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Sample records for aerospace structural applications

  1. Lattice Structures For Aerospace Applications

    NASA Astrophysics Data System (ADS)

    Del Olmo, E.; Grande, E.; Samartin, C. R.; Bezdenejnykh, M.; Torres, J.; Blanco, N.; Frovel, M.; Canas, J.

    2012-07-01

    The way of mass reduction improving performances in the aerospace structures is a constant and relevant challenge in the space business. The designs, materials and manufacturing processes are permanently in evolution to explore and get mass optimization solutions at low cost. In the framework of ICARO project, EADS CASA ESPACIO (ECE) has designed, manufactured and tested a technology demonstrator which shows that lattice type of grid structures is a promising weight saving solution for replacing some traditional metallic and composite structures for space applications. A virtual testing methodology was used in order to support the design of a high modulus CFRP cylindrical lattice technology demonstrator. The manufacturing process, based on composite Automatic Fiber Placement (AFP) technology developed by ECE, allows obtaining high quality low weight lattice structures potentially applicable to a wide range of aerospace structures. Launcher payload adaptors, satellite platforms, antenna towers or instrument supports are some promising candidates.

  2. A review of multifunctional structure technology for aerospace applications

    NASA Astrophysics Data System (ADS)

    Sairajan, K. K.; Aglietti, G. S.; Mani, K. M.

    2016-03-01

    The emerging field of multifunctional structure (MFS) technologies enables the design of systems with reduced mass and volume, thereby improving their overall efficiency. It requires developments in different engineering disciplines and their integration into a single system without degrading their individual performances. MFS is particularly suitable for aerospace applications where mass and volume are critical to the cost of the mission. This article reviews the current state of the art of multifunctional structure technologies relevant to aerospace applications.

  3. Challenges for Insertion of Structural Nanomaterials in Aerospace Applications

    NASA Technical Reports Server (NTRS)

    Sochi, Emilie J.

    2012-01-01

    In the two decades since Iijima's report on carbon nanotubes (CNT), there has been great interest in realizing the benefits of mechanical properties observed at the nanoscale in large-scale structures. The weight savings possible due to dramatic improvements in mechanical properties relative to state-of-the-art material systems can be game changing for applications like aerospace vehicles. While there has been significant progress in commercial production of CNTs, major aerospace applications that take advantage of properties offered by this material have yet to be realized. This paper provides a perspective on the technical challenges and barriers for insertion of CNTs as an emerging material technology in aerospace applications and proposes approaches that may reduce the typical timeframe for technology maturation and insertion into aerospace structures.

  4. Development of lightweight structural health monitoring systems for aerospace applications

    NASA Astrophysics Data System (ADS)

    Pearson, Matthew

    This thesis investigates the development of structural health monitoring systems (SHM) for aerospace applications. The work focuses on each aspect of a SHM system covering novel transducer technologies and damage detection techniques to detect and locate damage in metallic and composite structures. Secondly the potential of energy harvesting and power arrangement methodologies to provide a stable power source is assessed. Finally culminating in the realisation of smart SHM structures. 1. Transducer Technology A thorough experimental study of low profile, low weight novel transducers not normally used for acoustic emission (AE) and acousto-ultrasonics (AU) damage detection was conducted. This included assessment of their performance when exposed to aircraft environments and feasibility of embedding these transducers in composites specimens in order to realise smart structures. 2. Damage Detection An extensive experimental programme into damage detection utilising AE and AU were conducted in both composites and metallic structures. These techniques were used to assess different damage mechanism within these materials. The same transducers were used for novel AE location techniques coupled with AU similarity assessment to successfully detect and locate damage in a variety of structures. 3. Energy Harvesting and Power Management Experimental investigations and numerical simulations were undertaken to assess the power generation levels of piezoelectric and thermoelectric generators for typical vibration and temperature differentials which exist in the aerospace environment. Furthermore a power management system was assessed to demonstrate the ability of the system to take the varying nature of the input power and condition it to a stable power source for a system. 4. Smart Structures The research conducted is brought together into a smart carbon fibre wing showcasing the novel embedded transducers for AE and AU damage detection and location, as well as vibration energy

  5. Application of thermal spray coatings to aerospace structures

    SciTech Connect

    Novak, H.L.

    1994-12-31

    Reusable launch vehicles located by the ocean are subject to harsh seacoast environments before launch and immersion after splashdown at sea and tow back to the refurbishment facility. The use of various thermal spray processes for depositing corrosion and erosion protective materials to the alloy substrates has potential for enhancing the corrosion/erosion resistance and useful life of those expensive large reusable aerospace structures. Thermal spray processes such as high velocity oxygen fuel (HVOF), plasma, arc spray and conventional oxygen fuel spray and the IVD process (pure aluminum only) have been used to coat test panels and scrap flight hardware with various applied materials. Pure aluminum, aluminum/aluminum oxide matrix (DURALCAN), and pure zinc have been applied over 2219-T87 aluminum alloy, 4340 steel alloy substrates. Salt spray testing has been conducted in accordance with ASTM B-117 as well as beach exposure tests at Kennedy Space Center, Florida. Adhesion tests have been performed for all materials applied to the various substrates as well as monitoring of substrate temperatures during the spray process. The pure aluminum, zinc, and aluminum/aluminum oxide matrix material afforded excellent corrosion protection in both beach exposure and salt spray environments. in conclusion, tests and actual applications have shown that the various thermal spray processes and coating materials have significant potential for enhancing corrosion/erosion resistance and extending the useful service life of expensive aerospace structures exposed to marine environments. The ability to effectively repair damaged IVD aluminum coated substrates using arc sprayed material adds flexibility to the maintenance process. Due to the excellent adhesion and corrosion protection of the substrate, tests are underway to determine if chromate conversion coating can be eliminated prior to primer/topcoat application.

  6. Titanium cholla : lightweight, high-strength structures for aerospace applications.

    SciTech Connect

    Atwood, Clinton J.; Voth, Thomas Eugene; Taggart, David G.; Gill, David Dennis; Robbins, Joshua H.; Dewhurst, Peter

    2007-10-01

    Aerospace designers seek lightweight, high-strength structures to lower launch weight while creating structures that are capable of withstanding launch loadings. Most 'light-weighting' is done through an expensive, time-consuming, iterative method requiring experience and a repeated design/test/redesign sequence until an adequate solution is obtained. Little successful work has been done in the application of generalized 3D optimization due to the difficulty of analytical solutions, the large computational requirements of computerized solutions, and the inability to manufacture many optimized structures with conventional machining processes. The Titanium Cholla LDRD team set out to create generalized 3D optimization routines, a set of analytically optimized 3D structures for testing the solutions, and a method of manufacturing these complex optimized structures. The team developed two new computer optimization solutions: Advanced Topological Optimization (ATO) and FlexFEM, an optimization package utilizing the eXtended Finite Element Method (XFEM) software for stress analysis. The team also developed several new analytically defined classes of optimized structures. Finally, the team developed a 3D capability for the Laser Engineered Net Shaping{trademark} (LENS{reg_sign}) additive manufacturing process including process planning for 3D optimized structures. This report gives individual examples as well as one generalized example showing the optimized solutions and an optimized metal part.

  7. Health monitoring studies on composite structures for aerospace applications

    SciTech Connect

    James, G.; Roach, D.; Hansche, B.; Meza, R.; Robinson, N.

    1996-02-01

    This paper discusses ongoing work to develop structural health monitoring techniques for composite aerospace structures such as aircraft control surfaces, fuselage sections or repairs, and reusable launch vehicle fuel tanks. The overall project is divided into four tasks: Operational evaluation, diagnostic measurements, information condensation, and damage detection. Five composite plates were constructed to study delaminations, disbonds, and fluid retention issues as the initial step in creating an operational system. These four square feet plates were graphite-epoxy with nomex honeycomb cores. The diagnostic measurements are composed of modal tests with a scanning laser vibrometer at over 500 scan points per plate covering the frequency range up to 2000 Hz. This data has been reduced into experimental dynamics matrices using a generic, software package developed at the University of Colorado at Boulder. The continuing effort will entail performing a series of damage identification studies to detect, localize, and determine the extent of the damage. This work is providing understanding and algorithm development for a global NDE technique for composite aerospace structures.

  8. Aerospace Applications of Microprocessors

    NASA Technical Reports Server (NTRS)

    1980-01-01

    An assessment of the state of microprocessor applications is presented. Current and future requirements and associated technological advances which allow effective exploitation in aerospace applications are discussed.

  9. IPAD applications to the design, analysis, and/or machining of aerospace structures. [Integrated Program for Aerospace-vehicle Design

    NASA Technical Reports Server (NTRS)

    Blackburn, C. L.; Dovi, A. R.; Kurtze, W. L.; Storaasli, O. O.

    1981-01-01

    A computer software system for the processing and integration of engineering data and programs, called IPAD (Integrated Programs for Aerospace-Vehicle Design), is described. The ability of the system to relieve the engineer of the mundane task of input data preparation is demonstrated by the application of a prototype system to the design, analysis, and/or machining of three simple structures. Future work to further enhance the system's automated data handling and ability to handle larger and more varied design problems are also presented.

  10. Integration of piezoceramic actuators in fiber-reinforced structures for aerospace applications

    NASA Astrophysics Data System (ADS)

    Duerr, Johannes K.; Herold-Schmidt, Ursula; Zaglauer, Helmut W.; Arendts, Franz J.

    1998-06-01

    Up to now experimental and theoretical research on active structures for aerospace applications has put the focus mainly on surface bonded actuators. Simultaneously peizoceramics became the major type of actuating device being investigated for smart structures.In this context various techniques of insulating, bonding and operating these actuators have been developed. However, especially with regard to actuators only a few investigations have dealt with embedding of these components into the load bearing structure so far. With increasing shares of fiber- reinforced plastics applied in aerospace products the option of integrating the actuation capability into the components should be reconsidered during the design process. This paper deals with different aspects related to the integration of piezoceramic actuators into fiber reinforced aerospace structures. An outline of the basic possibilities of either bonding an actuator to the structure's surface or embedding it into the composite is given while the emphasis is put on different aspects related to the latter technology. Subsequently recent efforts at Daimler-Benz Aerospace Dornier concerning aircraft components with surface bonded actuators are presented. Design considerations regarding embedded piezoceramic actuators are discussed. Finally some techniques of non-destructive testing applicable to structures with surface bonded as well as embedded piezoelectric actuators are described.

  11. Structural Efficiency of Composite Struts for Aerospace Applications

    NASA Technical Reports Server (NTRS)

    Jegley, Dawn C.; Wu, K. Chauncey; McKenney, Martin J.; Oremont, Leonard

    2011-01-01

    The structural efficiency of carbon-epoxy tapered struts is considered through trade studies, detailed analysis, manufacturing and experimentation. Since some of the lunar lander struts are more highly loaded than struts used in applications such as satellites and telescopes, the primary focus of the effort is on these highly loaded struts. Lunar lander requirements include that the strut has to be tapered on both ends, complicating the design and limiting the manufacturing process. Optimal stacking sequences, geometries, and materials are determined and the sensitivity of the strut weight to each parameter is evaluated. The trade study results indicate that the most efficient carbon-epoxy struts are 30 percent lighter than the most efficient aluminum-lithium struts. Structurally efficient, highly loaded struts were fabricated and loaded in tension and compression to determine if they met the design requirements and to verify the accuracy of the analyses. Experimental evaluation of some of these struts demonstrated that they could meet the greatest Altair loading requirements in both tension and compression. These results could be applied to other vehicles requiring struts with high loading and light weight.

  12. Aerospace applications of batteries

    NASA Technical Reports Server (NTRS)

    Habib, Shahid

    1993-01-01

    NASA has developed battery technology to meet the demanding requirements for aerospace applications; specifically, the space vacuum, launch loads, and high duty cycles. Because of unique requirements and operating environments associated with space applications, NASA has written its own standards and specifications for batteries.

  13. Qualifying of metallic materials and structures for aerospace applications

    NASA Astrophysics Data System (ADS)

    Frazier, William E.; Polakovics, Donald; Koegel, Wayne

    2001-03-01

    The U.S. Navy’s certification and qualification process for materials and structures is undertaken to ensure the flight safety and full mission capability of naval aviation weapon systems. A building-block process is practiced in which validated engineering data and concepts provide the foundation for continued technological development and innovation. For example, prior to developing material-property standards, the manufacturing process is frozen and fully characterized. The customer’s cost, schedule, and performance requirements must be carefully considered. Technologies are selected for immediate use or further R&D based upon a risk assessment that takes into account many factors, including technological maturity, lessons learned, the sponsor budget and schedule constraints, affordability, return on investment, and life-cycle cost impact. This paper explores the process that the navy uses to qualify its airframe alloys and structures.

  14. Photogrammetric techniques for aerospace applications

    NASA Astrophysics Data System (ADS)

    Liu, Tianshu; Burner, Alpheus W.; Jones, Thomas W.; Barrows, Danny A.

    2012-10-01

    Photogrammetric techniques have been used for measuring the important physical quantities in both ground and flight testing including aeroelastic deformation, attitude, position, shape and dynamics of objects such as wind tunnel models, flight vehicles, rotating blades and large space structures. The distinct advantage of photogrammetric measurement is that it is a non-contact, global measurement technique. Although the general principles of photogrammetry are well known particularly in topographic and aerial survey, photogrammetric techniques require special adaptation for aerospace applications. This review provides a comprehensive and systematic summary of photogrammetric techniques for aerospace applications based on diverse sources. It is useful mainly for aerospace engineers who want to use photogrammetric techniques, but it also gives a general introduction for photogrammetrists and computer vision scientists to new applications.

  15. Trends in aerospace structures

    NASA Technical Reports Server (NTRS)

    Card, M. F.

    1978-01-01

    Recent developments indicate that there may soon be a revolution in aerospace structures. Increases in allowable operational stress levels, utilization of high-strength, high-toughness materials, and new structural concepts will highlight this advancement. Improved titanium and aluminum alloys and high-modulus, high-strength advanced composites, with higher specific properties than aluminum and high-strength nickel alloys, are expected to be the principal materials. Significant advances in computer technology will cause major changes in the preliminary design cycle and permit solutions of otherwise too-complex interactive structural problems and thus the development of vehicles and components of higher performance. The energy crisis will have an impact on material costs and choices and will spur the development of more weight-efficient structures. There will also be significant spinoffs of aerospace structures technology, particularly in composites and design/analysis software.

  16. Applications of aerospace technology

    NASA Technical Reports Server (NTRS)

    Rouse, Doris J.

    1984-01-01

    The objective of the Research Triangle Institute Technology Transfer Team is to assist NASA in achieving widespread utilization of aerospace technology in terrestrial applications. Widespread utilization implies that the application of NASA technology is to benefit a significant sector of the economy and population of the Nation. This objective is best attained by stimulating the introduction of new or improved commercially available devices incorporating aerospace technology. A methodology is presented for the team's activities as an active transfer agent linking NASA Field Centers, industry associations, user groups, and the medical community. This methodology is designed to: (1) identify priority technology requirements in industry and medicine, (2) identify applicable NASA technology that represents an opportunity for a successful solution and commercial product, (3) obtain the early participation of industry in the transfer process, and (4) successfully develop a new product based on NASA technology.

  17. Advanced Ceramic Materials for Future Aerospace Applications

    NASA Technical Reports Server (NTRS)

    Misra, Ajay

    2015-01-01

    With growing trend toward higher temperature capabilities, lightweight, and multifunctionality, significant advances in ceramic matrix composites (CMCs) will be required for future aerospace applications. The presentation will provide an overview of material requirements for future aerospace missions, and the role of ceramics and CMCs in meeting those requirements. Aerospace applications will include gas turbine engines, aircraft structure, hypersonic and access to space vehicles, space power and propulsion, and space communication.

  18. Magnetic Gearboxes for Aerospace Applications

    NASA Technical Reports Server (NTRS)

    Perez-Diaz, Jose Luis; Diez-Jimenez, Efren; Alvarez-Valenzuela, Marco A.; Sanchez-Garcia-Casarrubios, Juan; Cristache, Christian; Valiente-Blanco, Ignacio

    2014-01-01

    Magnetic gearboxes are contactless mechanisms for torque-speed conversion. They present no wear, no friction and no fatigue. They need no lubricant and can be customized for other mechanical properties as stiffness or damping. Additionally, they can protect structures and mechanisms against overloads, limitting the transmitted torque. In this work, spur, planetary and "magdrive" or "harmonic drive" configurations are compared considering their use in aerospace applications. The most recent test data are summarized to provide some useful help for the design engineer.

  19. The application of thermoelastic stress analysis to full-scale aerospace structures

    NASA Astrophysics Data System (ADS)

    Fruehmann, R. K.; Dulieu-Barton, J. M.; Quinn, S.; Peton-Walter, J.; Mousty, P. A. N.

    2012-08-01

    Non-destructive evaluation (NDE) techniques that can be applied in-situ are particularly relevant to the testing of large scale structures that cannot easily be taken into a laboratory for inspection. The application of established laboratory based techniques to the inspection of such structures therefore brings with it a new set of challenges associated with the change in operating environment between the laboratory and 'the field'. The current work investigates the use of thermoelastic stress analysis (TSA) to inspect carbon fibre composite aerospace components for manufacturing defects and in-service damage. An initial study using single transient loads to obtain a measureable change in temperature that can be related to the change in the sum of the principal stresses showed a good agreement with the traditional methodology. However, for large structures, the energy required to obtain a sufficiently large stress change to obtain a resolvable measurement may require an actuator that is not easily portable. Hence a number of ideas have been proposed to reduce the power requirement and deal with small signal to noise ratios. This paper describes the use of natural frequency vibration modes to enable large stress changes to be generated with minimal power input. Established signal processing in the form of a lock-in amplifier and Fourier signal analysis is applied. Tests on a laboratory scale flat plate and full-scale representative wing skin and stringer specimen are presented.

  20. Structures Technology for Future Aerospace Systems

    NASA Technical Reports Server (NTRS)

    Noor, Ahmed K.; Venneri, Samuel L.; Paul, Donald B.; Hopkins, Mark A.

    2000-01-01

    An overview of structures technology for future aerospace systems is given. Discussion focuses on developments in component technologies that will improve the vehicle performance, advance the technology exploitation process, and reduce system life-cycle costs. The component technologies described are smart materials and structures, multifunctional materials and structures, affordable composite structures, extreme environment structures, flexible load bearing structures, and computational methods and simulation-based design. The trends in each of the component technologies are discussed and the applicability of these technologies to future aerospace vehicles is described.

  1. Micromechanical Machining Processes and their Application to Aerospace Structures, Devices and Systems

    NASA Technical Reports Server (NTRS)

    Friedrich, Craig R.; Warrington, Robert O.

    1995-01-01

    Micromechanical machining processes are those micro fabrication techniques which directly remove work piece material by either a physical cutting tool or an energy process. These processes are direct and therefore they can help reduce the cost and time for prototype development of micro mechanical components and systems. This is especially true for aerospace applications where size and weight are critical, and reliability and the operating environment are an integral part of the design and development process. The micromechanical machining processes are rapidly being recognized as a complementary set of tools to traditional lithographic processes (such as LIGA) for the fabrication of micromechanical components. Worldwide efforts in the U.S., Germany, and Japan are leading to results which sometimes rival lithography at a fraction of the time and cost. Efforts to develop processes and systems specific to aerospace applications are well underway.

  2. Aerospace management techniques: Commercial and governmental applications

    NASA Technical Reports Server (NTRS)

    Milliken, J. G.; Morrison, E. J.

    1971-01-01

    A guidebook for managers and administrators is presented as a source of useful information on new management methods in business, industry, and government. The major topics discussed include: actual and potential applications of aerospace management techniques to commercial and governmental organizations; aerospace management techniques and their use within the aerospace sector; and the aerospace sector's application of innovative management techniques.

  3. Aerospace applications of advanced aluminum alloys

    NASA Technical Reports Server (NTRS)

    Chellman, D. J.; Langenbeck, S. L.

    1993-01-01

    Advanced metallic materials within the Al-base family are being developed for applications on current and future aerospace vehicles. These advanced materials offer significant improvements in density, strength, stiffness, fracture resistance, and/or higher use temperature which translates into improved vehicle performance. Aerospace applications of advanced metallic materials include space structures, fighters, military and commercial transport aircraft, and missiles. Structural design requirements, including not only static and durability/damage tolerance criteria but also environmental considerations, drive material selections. Often trade-offs must be made regarding strength, fracture resistance, cost, reliability, and maintainability in order to select the optimum material for a specific application. These trade studies not only include various metallic materials but also many times include advanced composite materials. Details of material comparisons, aerospace applications, and material trades will be presented.

  4. Wiring for aerospace applications

    NASA Technical Reports Server (NTRS)

    Christian, J. L., Jr.; Dickman, J. E.; Bercaw, R. W.; Myers, I. T.; Hammoud, A. N.; Stavnes, M.; Evans, J.

    1992-01-01

    In this paper, the authors summarize the current state of knowledge of arc propagation in aerospace power wiring and efforts by the National Aeronautics and Space Administration (NASA) towards the understanding of the arc tracking phenomena in space environments. Recommendations will be made for additional testing. A database of the performance of commonly used insulating materials will be developed to support the design of advanced high power missions, such as Space Station Freedom and Lunar/Mars Exploration.

  5. Automatix Incorporated in aerospace applications

    NASA Astrophysics Data System (ADS)

    Hilmer, C.

    1983-03-01

    Robotic assembly and artificial vision applications are currently employed or have potential in aerospace manufacturing. Automatix vision guided robotics have been used for electronic component assembly, welding of aluminum alloys with both gas metal arc welding (MIG). Other applications include gas tungsten arc welding (TIG), and visual gauging. The unique control concept has provided a single robotic controller with virtual robotic arm interchangeability.

  6. Novel Nanolaminates for Aerospace Applications

    NASA Technical Reports Server (NTRS)

    Volz, Martin; Mazuruk, consty

    2006-01-01

    Nanolaminate manufacturing (NLM) is a new way of developing materials whose properties can far exceed those of homogeneous materials. Traditional alloys, composites and bulk laminates tend to average the properties of the materials from which they were made. With nanostructured materials, the high density of interfaces between dissimilar materials results in novel material properties. For example, materials made -from alternating nanoscale layers of metals and oxides have exhibited thermal conductivities far below those of the oxides themselves. Also, metallic nanolaminates can have peak strengths 100 times lager than the bulk constituent metals. Recent work at MSFC has focused on the development of nickel/aluminum oxide (Ni/Al2O3)) nanolaminates. Ni/Al2O3 nanolaminates are expected to have better strength, creep and fatigue resistance, oxygen compatibility, and corrosion resistance than the traditional metal-matrix composites of this material, which has been used in a variety of aerospace applications. A chemical vapor deposition (CW) system has been developed and optimized for the deposition of nanolaminates. Nanolaminates with layer thicknesses between 10 and 300 nm have been successfully grown and characterization has included scanning electron microscopy (SEM) and atomic force microscopy (AFM) Nanolaminates have a large variety of potential applications. They can be tailored to have both very small and anisotropic thermal conductivities and are promising as thermal coatings for both rock$ engine components and aerobraking structures. They also have the potential to be used in aerospace applications where strength at high temperatures, corrosion resistance or resistance to hydrogen embrittlement is important. Both CVD and magnetron sputtering facilities are available for the deposition of nanolayered materials. Characterization equipment includes SEM, AFM, X-ray diffraction, transmission electron microscopy, optical profilometry, and mechanical tensile pull

  7. High density interconnects for aerospace applications

    NASA Astrophysics Data System (ADS)

    Menozzi, Gaetan

    1988-08-01

    The technologies of large scale interconnectors were evaluated for chip and wire or leadless ceramic chip carriers. The packaging and interconnecting structures are either ceramic multilayer with multilayer thick film and cofired multilayer ceramic. Test results are given, technology status and next generation interconnects are described, and aerospace applications are presented.

  8. Aerospace applications of magnetic bearings

    NASA Technical Reports Server (NTRS)

    Downer, James; Goldie, James; Gondhalekar, Vijay; Hockney, Richard

    1994-01-01

    Magnetic bearings have traditionally been considered for use in aerospace applications only where performance advantages have been the primary, if not only, consideration. Conventional wisdom has been that magnetic bearings have certain performance advantages which must be traded off against increased weight, volume, electric power consumption, and system complexity. These perceptions have hampered the use of magnetic bearings in many aerospace applications because weight, volume, and power are almost always primary considerations. This paper will review progress on several active aerospace magnetic bearings programs at SatCon Technology Corporation. The magnetic bearing programs at SatCon cover a broad spectrum of applications including: a magnetically-suspended spacecraft integrated power and attitude control system (IPACS), a magnetically-suspended momentum wheel, magnetic bearings for the gas generator rotor of a turboshaft engine, a vibration-attenuating magnetic bearing system for an airborne telescope, and magnetic bearings for the compressor of a space-rated heat pump system. The emphasis of these programs is to develop magnetic bearing technologies to the point where magnetic bearings can be truly useful, reliable, and well tested components for the aerospace community.

  9. Aerospace applications of magnetic bearings

    NASA Astrophysics Data System (ADS)

    Downer, James; Goldie, James; Gondhalekar, Vijay; Hockney, Richard

    1994-05-01

    Magnetic bearings have traditionally been considered for use in aerospace applications only where performance advantages have been the primary, if not only, consideration. Conventional wisdom has been that magnetic bearings have certain performance advantages which must be traded off against increased weight, volume, electric power consumption, and system complexity. These perceptions have hampered the use of magnetic bearings in many aerospace applications because weight, volume, and power are almost always primary considerations. This paper will review progress on several active aerospace magnetic bearings programs at SatCon Technology Corporation. The magnetic bearing programs at SatCon cover a broad spectrum of applications including: a magnetically-suspended spacecraft integrated power and attitude control system (IPACS), a magnetically-suspended momentum wheel, magnetic bearings for the gas generator rotor of a turboshaft engine, a vibration-attenuating magnetic bearing system for an airborne telescope, and magnetic bearings for the compressor of a space-rated heat pump system. The emphasis of these programs is to develop magnetic bearing technologies to the point where magnetic bearings can be truly useful, reliable, and well tested components for the aerospace community.

  10. Wireless Sensing Opportunities for Aerospace Applications

    NASA Technical Reports Server (NTRS)

    Wilson, William; Atkinson, Gary

    2007-01-01

    Wireless sensors and sensor networks is an emerging technology area with many applications within the aerospace industry. Integrated vehicle health monitoring (IVHM) of aerospace vehicles is needed to ensure the safety of the crew and the vehicle, yet often high costs, weight, size and other constraints prevent the incorporation of instrumentation onto spacecraft. This paper presents a few of the areas such as IVHM, where new wireless sensing technology is needed on both existing vehicles as well as future spacecraft. From ground tests to inflatable structures to the International Space Station, many applications could receive benefits from small, low power, wireless sensors. This paper also highlights some of the challenges that need to overcome when implementing wireless sensor networks for aerospace vehicles.

  11. Interdisciplinary optimum design. [of aerospace structures

    NASA Technical Reports Server (NTRS)

    Sobieszczanski-Sobieski, Jaroslaw; Haftka, Raphael T.

    1986-01-01

    Problems related to interdisciplinary interactions in the design of a complex engineering systems are examined with reference to aerospace applications. The interdisciplinary optimization problems examined include those dealing with controls and structures, materials and structures, control and stability, structure and aerodynamics, and structure and thermodynamics. The discussion is illustrated by the following specific applications: integrated aerodynamic/structural optimization of glider wing; optimization of an antenna parabolic dish structure for minimum weight and prescribed emitted signal gain; and a multilevel optimization study of a transport aircraft.

  12. Aerospace materials for nonaerospace applications

    NASA Technical Reports Server (NTRS)

    Johnston, R. L.; Dawn, F. S.

    1974-01-01

    Many of the flame-resistant nonmetallic materials that were developed for the Apollo and Skylab programs are discussed for commercial and military applications. Interchanges of information are taking place with the government agencies, industries, and educational institutions, which are interested in applications of fire-safe nonmetallic materials. These materials are particularly applicable to the design of aircraft, mass transit interiors, residential and public building constructions, nursing homes and hospitals, and to other fields of fire safety applications. Figures 22, 23 and 24 show the potential nonaerospace applications of flame-resistant aerospace materials are shown.

  13. Anechoic Chambers: Aerospace Applications. (Latest Citations from the Aerospace Database)

    NASA Technical Reports Server (NTRS)

    1996-01-01

    The bibliography contains citations concerning the design, development, performance, and applications of anechoic chambers in the aerospace industry. Anechoic chamber testing equipment, techniques for evaluation of aerodynamic noise, microwave and radio antennas, and other acoustic measurement devices are considered. Shock wave studies on aircraft models and components, electromagnetic measurements, jet flow studies, and antenna radiation pattern measurements for industrial and military aerospace equipment are discussed. (Contains 50-250 citations and includes a subject term index and title list.)

  14. Anechoic Chambers: Aerospace Applications. (Latest Citations from the Aerospace Database)

    NASA Technical Reports Server (NTRS)

    1995-01-01

    The bibliography contains citations concerning the design, development, performance, and applications of anechoic chambers in the aerospace industry. Anechoic chamber testing equipment, techniques for evaluation of aerodynamic noise, microwave and radio antennas, and other acoustic measurement devices are considered. Shock wave studies on aircraft models and components, electromagnetic measurements, jet flow studies, and antenna radiation pattern measurements for industrial and military aerospace equipment are discussed. (Contains 50-250 citations and includes a subject term index and title list.)

  15. Validating finite element models of composite aerospace structures for damage detection applications

    NASA Astrophysics Data System (ADS)

    Oliver, J. A.; Kosmatka, J. B.; Hemez, François M.; Farrar, Charles R.

    2006-03-01

    Carbon-fiber-reinforced-polymer (CFRP) composites represent the future for advanced lightweight aerospace structures. However, reliable and cost-effective techniques for structural health monitoring (SHM) are needed. Modal and vibration-based analysis, when combined with validated finite element (FE) models, can provide a key tool for SHM. Finite element models, however, can easily give spurious and misleading results if not finely tuned and validated. These problems are amplified in complex structures with numerous joints and interfaces. A small series of all-composite test pieces emulating wings from a lightweight all-composite Unmanned Aerial Vehicle (UAV) have been developed to support damage detection and SHM research. Each wing comprises two CFRP prepreg and Nomex honeycomb co-cured skins and two CFRP prepreg spars bonded together in a secondary process using a structural adhesive to form the complete wings. The first of the set is fully healthy while the rest have damage in the form of disbonds built into the main spar-skin bondline. Detailed FE models were created of the four structural components and the assembled structure. Each wing component piece was subjected to modal characterization via vibration testing using a shaker and scanning laser Doppler vibrometer before assembly. These results were then used to correlate the FE model on a component-basis, through fitting and optimization of polynomial meta-models. Assembling and testing the full wing provided subsequent data that was used to validate the numerical model of the entire structure, assembled from the correlated component models. The correlation process led to the following average percent improvement between experimental and FE frequencies of the first 20 modes for each piece: top skin 10.98%, bottom skin 45.62%, main spar 25.56%, aft spar 10.79%. The assembled wing model with no further correlation showed an improvement of 32.60%.

  16. Cognitive engineering in aerospace applications

    NASA Technical Reports Server (NTRS)

    Woods, David D.

    1993-01-01

    The progress that was made with respect to the objectives and goals of the research that is being carried out in the Cognitive Systems Engineering Laboratory (CSEL) under a Cooperative Agreement with NASA Ames Research Center is described. The major objective of this project is to expand the research base in Cognitive Engineering to be able to support the development and human-centered design of automated systems for aerospace applications. This research project is in support of the Aviation Safety/Automation Research plan and related NASA research goals in space applications.

  17. Adaptive control with aerospace applications

    NASA Astrophysics Data System (ADS)

    Gadient, Ross

    Robust and adaptive control techniques have a rich history of theoretical development with successful application. Despite the accomplishments made, attempts to combine the best elements of each approach into robust adaptive systems has proven challenging, particularly in the area of application to real world aerospace systems. In this research, we investigate design methods for general classes of systems that may be applied to representative aerospace dynamics. By combining robust baseline control design with augmentation designs, our work aims to leverage the advantages of each approach. This research contributes the development of robust model-based control design for two classes of dynamics: 2nd order cascaded systems, and a more general MIMO framework. We present a theoretically justified method for state limiting via augmentation of a robust baseline control design. Through the development of adaptive augmentation designs, we are able to retain system performance in the presence of uncertainties. We include an extension that combines robust baseline design with both state limiting and adaptive augmentations. In addition we develop an adaptive augmentation design approach for a class of dynamic input uncertainties. We present formal stability proofs and analyses for all proposed designs in the research. Throughout the work, we present real world aerospace applications using relevant flight dynamics and flight test results. We derive robust baseline control designs with application to both piloted and unpiloted aerospace system. Using our developed methods, we add a flight envelope protecting state limiting augmentation for piloted aircraft applications and demonstrate the efficacy of our approach via both simulation and flight test. We illustrate our adaptive augmentation designs via application to relevant fixed-wing aircraft dynamics. Both a piloted example combining the state limiting and adaptive augmentation approaches, and an unpiloted example with

  18. Microelectronics packaging research directions for aerospace applications

    NASA Technical Reports Server (NTRS)

    Galbraith, L.

    2003-01-01

    The Roadmap begins with an assessment of needs from the microelectronics for aerospace applications viewpoint. Needs Assessment is divided into materials, packaging components, and radiation characterization of packaging.

  19. Energy Storage for Aerospace Applications

    NASA Technical Reports Server (NTRS)

    Perez-Davis, Marla E.; Loyselle, Patricia L.; Hoberecht, Mark A.; Manzo, Michelle A.; Kohout, Lisa L.; Burke, Kenneth A.; Cabrera, Carlos R.

    2001-01-01

    The NASA Glenn Research Center (GRC) has long been a major contributor to the development and application of energy storage technologies for NASAs missions and programs. NASA GRC has supported technology efforts for the advancement of batteries and fuel cells. The Electrochemistry Branch at NASA GRC continues to play a critical role in the development and application of energy storage technologies, in collaboration with other NASA centers, government agencies, industry and academia. This paper describes the work in batteries and fuel cell technologies at the NASA Glenn Research Center. It covers a number of systems required to ensure that NASAs needs for a wide variety of systems are met. Some of the topics covered are lithium-based batteries, proton exchange membrane (PEM) fuel cells, and nanotechnology activities. With the advances of the past years, we begin the 21st century with new technical challenges and opportunities as we develop enabling technologies for batteries and fuel cells for aerospace applications.

  20. Automated design of aerospace structures

    NASA Technical Reports Server (NTRS)

    Fulton, R. E.; Mccomb, H. G.

    1974-01-01

    The current state-of-the-art in structural analysis of aerospace vehicles is characterized, automated design technology is discussed, and an indication is given of the future direction of research in analysis and automated design. Representative computer programs for analysis typical of those in routine use in vehicle design activities are described, and results are shown for some selected analysis problems. Recent and planned advances in analysis capability are indicated. Techniques used to automate the more routine aspects of structural design are discussed, and some recently developed automated design computer programs are described. Finally, discussion is presented of early accomplishments in interdisciplinary automated design systems, and some indication of the future thrust of research in this field is given.

  1. Development of Advanced Aluminum Alloys from Rapidly Solidified Powders for Aerospace Structural Applications

    DTIC Science & Technology

    1980-03-01

    density, compared to Al 7075 -T76, without significant loss in modu- lus, toughness, fatigue behavior , or stress corrosion resistance. Selective... 7075 -T76, without significant loss in modu- lus, toughness, fatigue behavior , or stress corrosion resistance. Selective application of the two advanced...density ratio, when compared to Al 7075 -T76 and without a significant loss in other properties important for structural applications. The program is

  2. Materials research. [research concerning materials for aerospace applications

    NASA Technical Reports Server (NTRS)

    1973-01-01

    The research is reported concerned with materials for aerospace applications. Areas reported include: electrical properties of glasses, oxides and metals; structural and high temperature properties of crystalline and amorphous materials; and physical properties, and microstructure of materials.

  3. Aerospace Power Technology for Potential Terrestrial Applications

    NASA Technical Reports Server (NTRS)

    Lyons, Valerie J.

    2012-01-01

    Aerospace technology that is being developed for space and aeronautical applications has great potential for providing technical advances for terrestrial power systems. Some recent accomplishments arising from activities being pursued at the National Aeronautics and Space Administration (NASA) Centers is described in this paper. Possible terrestrial applications of the new aerospace technology are also discussed.

  4. High Performance Fortran for Aerospace Applications

    NASA Technical Reports Server (NTRS)

    Mehrotra, Piyush; Zima, Hans; Bushnell, Dennis M. (Technical Monitor)

    2000-01-01

    This paper focuses on the use of High Performance Fortran (HPF) for important classes of algorithms employed in aerospace applications. HPF is a set of Fortran extensions designed to provide users with a high-level interface for programming data parallel scientific applications, while delegating to the compiler/runtime system the task of generating explicitly parallel message-passing programs. We begin by providing a short overview of the HPF language. This is followed by a detailed discussion of the efficient use of HPF for applications involving multiple structured grids such as multiblock and adaptive mesh refinement (AMR) codes as well as unstructured grid codes. We focus on the data structures and computational structures used in these codes and on the high-level strategies that can be expressed in HPF to optimally exploit the parallelism in these algorithms.

  5. Chemical Microsensor Development for Aerospace Applications

    NASA Technical Reports Server (NTRS)

    Xu, Jennifer C.; Hunter, Gary W.; Lukco, Dorothy; Chen, Liangyu; Biaggi-Labiosa, Azlin M.

    2013-01-01

    Numerous aerospace applications, including low-false-alarm fire detection, environmental monitoring, fuel leak detection, and engine emission monitoring, would benefit greatly from robust and low weight, cost, and power consumption chemical microsensors. NASA Glenn Research Center has been working to develop a variety of chemical microsensors with these attributes to address the aforementioned applications. Chemical microsensors using different material platforms and sensing mechanisms have been produced. Approaches using electrochemical cells, resistors, and Schottky diode platforms, combined with nano-based materials, high temperature solid electrolytes, and room temperature polymer electrolytes have been realized to enable different types of microsensors. By understanding the application needs and chemical gas species to be detected, sensing materials and unique microfabrication processes were selected and applied. The chemical microsensors were designed utilizing simple structures and the least number of microfabrication processes possible, while maintaining high yield and low cost. In this presentation, an overview of carbon dioxide (CO2), oxygen (O2), and hydrogen/hydrocarbons (H2/CxHy) microsensors and their fabrication, testing results, and applications will be described. Particular challenges associated with improving the H2/CxHy microsensor contact wire-bonding pad will be discussed. These microsensors represent our research approach and serve as major tools as we expand our sensor development toolbox. Our ultimate goal is to develop robust chemical microsensor systems for aerospace and commercial applications.

  6. Intelligent Multi-scale Sensors for Damage Identification and Mitigation in Woven Composites for Aerospace Structural Applications

    DTIC Science & Technology

    2012-08-15

    resulting from project: Journal Publications 1. R. Garret , K. Peters and M. A. Zikry (2009), “In-situ Impact-induced Damage Assessment of Woven...Polymer Composites,” to be submitted. Conference Proceedings Publications 1. R. Garret , J. Pearson, K. Peters and M. Zikry (2007...Structures Technologies for Civil, Mechanical and Aerospace Systems, Smart Materials and Structures, San Diego, CA, 6529. 2. R. Garret , K. Peters

  7. Application of artificial neural networks to the design optimization of aerospace structural components

    NASA Technical Reports Server (NTRS)

    Berke, Laszlo; Patnaik, Surya N.; Murthy, Pappu L. N.

    1993-01-01

    The application of artificial neural networks to capture structural design expertise is demonstrated. The principal advantage of a trained neural network is that it requires trivial computational effort to produce an acceptable new design. For the class of problems addressed, the development of a conventional expert system would be extremely difficult. In the present effort, a structural optimization code with multiple nonlinear programming algorithms and an artificial neural network code NETS were used. A set of optimum designs for a ring and two aircraft wings for static and dynamic constraints were generated by using the optimization codes. The optimum design data were processed to obtain input and output pairs, which were used to develop a trained artificial neural network with the code NETS. Optimum designs for new design conditions were predicted by using the trained network. Neural net prediction of optimum designs was found to be satisfactory for most of the output design parameters. However, results from the present study indicate that caution must be exercised to ensure that all design variables are within selected error bounds.

  8. New insulation constructions for aerospace wiring applications

    NASA Technical Reports Server (NTRS)

    Slenski, George

    1994-01-01

    Outlined in this presentation is the background to insulation constructions for aerospace wiring applications, the Air Force wiring policy, the purpose and contract requirements of new insulation constructions, the test plan, and the test results.

  9. Mobile Computing for Aerospace Applications

    NASA Technical Reports Server (NTRS)

    Alena, Richard; Swietek, Gregory E. (Technical Monitor)

    1994-01-01

    The use of commercial computer technology in specific aerospace mission applications can reduce the cost and project cycle time required for the development of special-purpose computer systems. Additionally, the pace of technological innovation in the commercial market has made new computer capabilities available for demonstrations and flight tests. Three areas of research and development being explored by the Portable Computer Technology Project at NASA Ames Research Center are the application of commercial client/server network computing solutions to crew support and payload operations, the analysis of requirements for portable computing devices, and testing of wireless data communication links as extensions to the wired network. This paper will present computer architectural solutions to portable workstation design including the use of standard interfaces, advanced flat-panel displays and network configurations incorporating both wired and wireless transmission media. It will describe the design tradeoffs used in selecting high-performance processors and memories, interfaces for communication and peripheral control, and high resolution displays. The packaging issues for safe and reliable operation aboard spacecraft and aircraft are presented. The current status of wireless data links for portable computers is discussed from a system design perspective. An end-to-end data flow model for payload science operations from the experiment flight rack to the principal investigator is analyzed using capabilities provided by the new generation of computer products. A future flight experiment on-board the Russian MIR space station will be described in detail including system configuration and function, the characteristics of the spacecraft operating environment, the flight qualification measures needed for safety review, and the specifications of the computing devices to be used in the experiment. The software architecture chosen shall be presented. An analysis of the

  10. Application of composites to the selective reinforcement of metallic aerospace structures. [application of structural design criteria for weight reduction

    NASA Technical Reports Server (NTRS)

    Brooks, W. A., Jr.; Mathauser, E. E.; Pride, R. A.

    1972-01-01

    The use of composite materials to selectively reinforce metallic structures provides a low-cost way to reduce weight and a means of minimizing the risks usually associated with the introduction of new materials. An overview is presented of the NASA Langley Research Center programs to identify the advantages and to develop the potential of the selective reinforcement approach to the use of composites. These programs have shown that selective reinforcement provides excellent strength and stiffness improvements to metallic structures. Significant weight savings can be obtained in a cost effective manner. Flight service programs which have been initiated to validate further the merits of selective reinforcement are described.

  11. Applications of integrated design/analysis systems in aerospace structural design

    NASA Technical Reports Server (NTRS)

    Mason, Philip; Lerner, Edwin; Sobel, Lawrence

    1989-01-01

    Integrated structural analysis and design systems and structural optimization procedures are being used in a production environment. Successful use of these systems requires experienced personnel. Interactive computer graphics can and will play a significant role in the analysis, optimization, design and manufacturing areas. Practical structural optimization procedures are tools that must be made available to the team. Much work still needs to be done to tie finite-element modeling to actual design details which are being tracked on systems such as CADAM or CATIA. More work needs to be done to automate the detailed design and analysis process. More emphasis should be placed on the real design problems.

  12. Novel Wiring Technologies for Aerospace Applications

    NASA Technical Reports Server (NTRS)

    Gibson, Tracy L.; Parrish, Lewis M.

    2014-01-01

    Because wire failure in aerospace vehicles could be catastrophic, smart wiring capabilities have been critical for NASA. Through the years, researchers at Kennedy Space Center (KSC) have developed technologies, expertise, and research facilities to meet this need. In addition to aerospace applications, NASA has applied its knowledge of smart wiring, including self-healing materials, to serve the aviation industry. This webinar will discuss the development efforts of several wiring technologies at KSC and provide insight into both current and future research objectives.

  13. Application of composites to the selective reinforcement of metallic aerospace structures

    NASA Technical Reports Server (NTRS)

    Brooks, W. A., Jr.; Mathauser, E. E.; Pride, R. A.

    1973-01-01

    The use of composite materials to selectively reinforce metallic structures provides a low-cost way to reduce weight and a means of minimizing the risks usually associated with the introduction of new materials. An overview is presented of the NASA Langley Research Center programs to identify the advantages and to develop the potential of the selective reinforcement approach to the use of composites. These programs have shown that selective reinforcement provides excellent strength and stiffness improvements to metallic structures. Significant weight savings can be obtained in a cost effective manner. Flight service programs which have been initiated to validate further the merits of selective reinforcement are described.

  14. Metal Matrix Composite Materials for Aerospace Applications

    NASA Technical Reports Server (NTRS)

    Bhat, Biliyar N.; Jones, C. S. (Technical Monitor)

    2001-01-01

    Metal matrix composites (MMC) are attractive materials for aerospace applications because of their high specific strength, high specific stiffness, and lower thermal expansion coefficient. They are affordable since complex parts can be produced by low cost casting process. As a result there are many commercial and Department of Defense applications of MMCs today. This seminar will give an overview of MMCs and their state-of-the-art technology assessment. Topics to be covered are types of MMCs, fabrication methods, product forms, applications, and material selection issues for design and manufacture. Some examples of current and future aerospace applications will also be presented and discussed.

  15. Review of the probabilistic failure analysis methodology and other probabilistic approaches for application in aerospace structural design

    NASA Technical Reports Server (NTRS)

    Townsend, J.; Meyers, C.; Ortega, R.; Peck, J.; Rheinfurth, M.; Weinstock, B.

    1993-01-01

    Probabilistic structural analyses and design methods are steadily gaining acceptance within the aerospace industry. The safety factor approach to design has long been the industry standard, and it is believed by many to be overly conservative and thus, costly. A probabilistic approach to design may offer substantial cost savings. This report summarizes several probabilistic approaches: the probabilistic failure analysis (PFA) methodology developed by Jet Propulsion Laboratory, fast probability integration (FPI) methods, the NESSUS finite element code, and response surface methods. Example problems are provided to help identify the advantages and disadvantages of each method.

  16. Advanced Materials and Coatings for Aerospace Applications

    NASA Technical Reports Server (NTRS)

    Miyoshi, Kazuhisa

    2004-01-01

    In the application area of aerospace tribology, researchers and developers must guarantee the highest degree of reliability for materials, components, and systems. Even a small tribological failure can lead to catastrophic results. The absence of the required knowledge of tribology, as Professor H.P. Jost has said, can act as a severe brake in aerospace vehicle systems-and indeed has already done so. Materials and coatings must be able to withstand the aerospace environments that they encounter, such as vacuum terrestrial, ascent, and descent environments; be resistant to the degrading effects of air, water vapor, sand, foreign substances, and radiation during a lengthy service; be able to withstand the loads, stresses, and temperatures encountered form acceleration and vibration during operation; and be able to support reliable tribological operations in harsh environments throughout the mission of the vehicle. This presentation id divided into two sections: surface properties and technology practice related to aerospace tribology. The first section is concerned with the fundamental properties of the surfaces of solid-film lubricants and related materials and coatings, including carbon nanotubes. The second is devoted to applications. Case studies are used to review some aspects of real problems related to aerospace systems to help engineers and scientists to understand the tribological issues and failures. The nature of each problem is analyzed, and the tribological properties are examined. All the fundamental studies and case studies were conducted at the NASA Glenn Research Center.

  17. Information processing for aerospace structural health monitoring

    NASA Astrophysics Data System (ADS)

    Lichtenwalner, Peter F.; White, Edward V.; Baumann, Erwin W.

    1998-06-01

    Structural health monitoring (SHM) technology provides a means to significantly reduce life cycle of aerospace vehicles by eliminating unnecessary inspections, minimizing inspection complexity, and providing accurate diagnostics and prognostics to support vehicle life extension. In order to accomplish this, a comprehensive SHM system will need to acquire data from a wide variety of diverse sensors including strain gages, accelerometers, acoustic emission sensors, crack growth gages, corrosion sensors, and piezoelectric transducers. Significant amounts of computer processing will then be required to convert this raw sensor data into meaningful information which indicates both the diagnostics of the current structural integrity as well as the prognostics necessary for planning and managing the future health of the structure in a cost effective manner. This paper provides a description of the key types of information processing technologies required in an effective SHM system. These include artificial intelligence techniques such as neural networks, expert systems, and fuzzy logic for nonlinear modeling, pattern recognition, and complex decision making; signal processing techniques such as Fourier and wavelet transforms for spectral analysis and feature extraction; statistical algorithms for optimal detection, estimation, prediction, and fusion; and a wide variety of other algorithms for data analysis and visualization. The intent of this paper is to provide an overview of the role of information processing for SHM, discuss various technologies which can contribute to accomplishing this role, and present some example applications of information processing for SHM implemented at the Boeing Company.

  18. NASA-UVa light aerospace alloy and structures technology program

    NASA Technical Reports Server (NTRS)

    Gangloff, Richard P.; Haviland, John K.; Herakovich, Carl T.; Pilkey, Walter D.; Pindera, Marek-Jerzy; Scully, John R.; Stoner, Glenn E.; Swanson, Robert E.; Thornton, Earl A.; Wawner, Franklin E., Jr.

    1991-01-01

    The general objective of the NASA-UVa Light Aerospace Alloy and Structures Technology Program was to conduct research on the performance of next generation, light weight aerospace alloys, composites, and associated thermal gradient structures. The following research areas were actively investigated: (1) mechanical and environmental degradation mechanisms in advanced light metals and composites; (2) aerospace materials science; (3) mechanics of materials and composites for aerospace structures; and (4) thermal gradient structures.

  19. Recent advancement in optical fiber sensing for aerospace composite structures

    NASA Astrophysics Data System (ADS)

    Minakuchi, Shu; Takeda, Nobuo

    2013-12-01

    Optical fiber sensors have attracted considerable attention in health monitoring of aerospace composite structures. This paper briefly reviews our recent advancement mainly in Brillouin-based distributed sensing. Damage detection, life cycle monitoring and shape reconstruction systems applicable to large-scale composite structures are presented, and new technical concepts, "smart crack arrester" and "hierarchical sensing system", are described as well, highlighting the great potential of optical fiber sensors for the structural health monitoring (SHM) field.

  20. Aerospace applications of nickel-cadmium batteries

    SciTech Connect

    Habib, S. )

    1993-05-01

    Some recent NASA applications of Ni-Cd batteries are Magellan, Topex/Poseidon, and the Tracking and Data Relay Satellite. Each of these automated spacecraft has a design lifetime of at least 3 years. Characteristics of the battery systems for each of these applications are given. Other topics discussed include the NASA standard Ni-Cd battery, the aerospace flight battery systems program, and the impact of the pending OHSA ruling.

  1. Technology Applications Team: Applications of aerospace technology

    NASA Technical Reports Server (NTRS)

    1993-01-01

    Highlights of the Research Triangle Institute (RTI) Applications Team activities over the past quarter are presented in Section 1.0. The Team's progress in fulfilling the requirements of the contract is summarized in Section 2.0. In addition to our market-driven approach to applications project development, RTI has placed increased effort on activities to commercialize technologies developed at NASA Centers. These Technology Commercialization efforts are summarized in Section 3.0. New problem statements prepared by the Team in the reporting period are presented in Section 4.0. The Team's transfer activities for ongoing projects with the NASA Centers are presented in Section 5.0. Section 6.0 summarizes the status of four add-on tasks. Travel for the reporting period is described in Section 7.0. The RTI Team staff and consultants and their project responsibilities are listed in Appendix A. The authors gratefully acknowledge the contributions of many individuals to the RTI Technology Applications Team program. The time and effort contributed by managers, engineers, and scientists throughout NASA were essential to program success. Most important to the program has been a productive working relationship with the NASA Field Center Technology Utilization (TU) Offices. The RTI Team continues to strive for improved effectiveness as a resource to these offices. Industry managers, technical staff, medical researchers, and clinicians have been cooperative and open in their participation. The RTI Team looks forward to continuing expansion of its interaction with U.S. industry to facilitate the transfer of aerospace technology to the private sector.

  2. Research needs in aerospace structural dynamics

    NASA Technical Reports Server (NTRS)

    Amos, A. K.; Goetz, R. C.

    1979-01-01

    The perspective of a NASA Ad Hoc Study Committee on future research needs in structural dynamics within the aerospace industry is presented. It identifies the common aspects of the design process across the industry and establishes the role of structural dynamics in it through a discussion of various design considerations having their basis in structural dynamics. The specific structural dynamics issues involved in these considerations are identified and assessed as to their current technological status and trends. Projections of future requirements based on this assessment are made and areas of research to meet them are identified.

  3. Actively controlled shaft seals for aerospace applications

    NASA Technical Reports Server (NTRS)

    Salant, Richard F.

    1991-01-01

    The main objective is to determine the feasibility of utilizing controllable mechanical seals for aerospace applications. A potential application was selected as a demonstration case: the buffer gas seal in a LOX (liquid oxygen) turbopump. Currently, floating ring seals are used in this application. Their replacement with controllable mechanical seals would result in substantially reduced leakage rates. This would reduce the required amount of stored buffer gas, and therefore increase the vehicle payload. For such an application, a suitable controllable mechanical seal was designed and analyzed.

  4. Computational composite mechanics for aerospace propulsion structures

    NASA Technical Reports Server (NTRS)

    Chamis, Christos C.

    1987-01-01

    Specialty methods are presented for the computational simulation of specific composite behavior. These methods encompass all aspects of composite mechanics, impact, progressive fracture and component specific simulation. Some of these methods are structured to computationally simulate, in parallel, the composite behavior and history from the initial frabrication through several missions and even to fracture. Select methods and typical results obtained from such simulations are described in detail in order to demonstrate the effectiveness of computationally simulating: (1) complex composite structural behavior in general, and (2) specific aerospace propulsion structural components in particular.

  5. Computational composite mechanics for aerospace propulsion structures

    NASA Technical Reports Server (NTRS)

    Chamis, C. C.

    1986-01-01

    Specialty methods are presented for the computational simulation of specific composite behavior. These methods encompass all aspects of composite mechanics, impact, progressive fracture and component specific simulation. Some of these methods are structured to computationally simulate, in parallel, the composite behavior and history from the initial fabrication through several missions and even to fracture. Select methods and typical results obtained from such simulations are described in detail in order to demonstrate the effectiveness of computationally simulating (1) complex composite structural behavior in general and (2) specific aerospace propulsion structural components in particular.

  6. Chemical Gas Sensors for Aerospace Applications

    NASA Technical Reports Server (NTRS)

    Hunter, Gary W.; Liu, C. C.

    1998-01-01

    Chemical sensors often need to be specifically designed (or tailored) to operate in a given environment. It is often the case that a chemical sensor that meets the needs of one application will not function adequately in another application. The more demanding the environment and specialized the requirement, the greater the need to adapt exiting sensor technologies to meet these requirements or, as necessary, develop new sensor technologies. Aerospace (aeronautic and space) applications are particularly challenging since often these applications have specifications which have not previously been the emphasis of commercial suppliers. Further, the chemical sensing needs of aerospace applications have changed over the years to reflect the changing emphasis of society. Three chemical sensing applications of particular interest to the National Aeronautics and Space Administration (NASA) which illustrate these trends are launch vehicle leak detection, emission monitoring, and fire detection. Each of these applications reflects efforts ongoing throughout NASA. As described in NASA's "Three Pillars for Success", a document which outlines NASA's long term response to achieve the nation's priorities in aerospace transportation, agency wide objectives include: improving safety and decreasing the cost of space travel, significantly decreasing the amount of emissions produced by aeronautic engines, and improving the safety of commercial airline travel. As will be discussed below, chemical sensing in leak detection, emission monitoring, and fire detection will help enable the agency to meet these objectives. Each application has vastly different problems associated with the measurement of chemical species. Nonetheless, the development of a common base technology can address the measurement needs of a number of applications.

  7. Bearing and gear steels for aerospace applications

    NASA Technical Reports Server (NTRS)

    Zaretsky, Erwin V.

    1990-01-01

    Research in metallurgy and processing for bearing and gear steels has resulted in improvements in rolling-element bearing and gear life for aerospace application by a factor of approximately 200 over that obtained in the early 1940's. The selection and specification of a bearing or gear steel is dependent on the integration of multiple metallurgical and physical variables. For most aerospace bearings, through-hardened VIM-VAR AISI M-50 steel is the material of preference. For gears, the preferential material is case-carburized VAR AISI 9310. However, the VAR processing for this material is being replaced by VIM-VAR processing. Since case-carburized VIM-VAR M-50NiL incorporates the desirable qualities of both the AISI M-50 and AISI 9310 materials, optimal life and reliability can be achieved in both bearings and gears with a single steel. Hence, this material offers the promise of a common steel for both bearings and gears for future aerospace applications.

  8. Aerospace applications of pulsed plasmas

    NASA Astrophysics Data System (ADS)

    Starikovskiy, Andrey

    2012-10-01

    The use of a thermal equilibrium plasma for combustion control dates back more than a hundred years to the advent of internal combustion (IC) engines and spark ignition systems. The same principles are still applied today to achieve high efficiency in various applications. Recently, the potential use of nonequilibrium plasma for ignition and combustion control has garnered increasing interest due to the possibility of plasma-assisted approaches for ignition and flame stabilization. During the past decade, significant progress has been made toward understanding the mechanisms of plasma chemistry interactions, energy redistribution and the nonequilibrium initiation of combustion. In addition, a wide variety of fuels have been examined using various types of discharge plasmas. Plasma application has been shown to provide additional combustion control, which is necessary for ultra-lean flames, high-speed flows, cold low-pressure conditions of high-altitude gas turbine engine (GTE) relight, detonation initiation in pulsed detonation engines (PDE) and distributed ignition control in homogeneous charge-compression ignition (HCCI) engines, among others. The present paper describes the current understanding of the nonequilibrium excitation of combustible mixtures by electrical discharges and plasma-assisted ignition and combustion. Nonequilibrium plasma demonstrates an ability to control ultra-lean, ultra-fast, low-temperature flames and appears to be an extremely promising technology for a wide range of applications, including aviation GTEs, piston engines, ramjets, scramjets and detonation initiation for pulsed detonation engines. To use nonequilibrium plasma for ignition and combustion in real energetic systems, one must understand the mechanisms of plasma-assisted ignition and combustion and be able to numerically simulate the discharge and combustion processes under various conditions.

  9. Key Issues for Aerospace Applications of Ceramic Matrix Composites

    NASA Technical Reports Server (NTRS)

    Clinton, R. G., Jr.; Levine, S. R.

    1998-01-01

    Ceramic matrix composites (CMC) offer significant advantages for future aerospace applications including turbine engine and liquid rocket engine components, thermal protection systems, and "hot structures". Key characteristics which establish ceramic matrix composites as attractive and often enabling choices are strength retention at high temperatures and reduced weight relative to currently used metallics. However, due to the immaturity of this class of materials which is further compounded by the lack of experience with CMC's in the aerospace industry, there are significant challenges involved in the development and implementation of ceramic matrix composites into aerospace systems. Some of the more critical challenges are attachment and load transfer methodologies; manufacturing techniques, particularly scale up to large and thick section components; operational environment resistance; damage tolerance; durability; repair techniques; reproducibility; database availability; and the lack of validated design and analysis tools. The presentation will examine the technical issues confronting the application of ceramic matrix composites to aerospace systems and identify the key material systems having potential for substantial payoff relative to the primary requirements of light weight and reduced cost for future systems. Current programs and future research opportunities will be described in the presentation which will focus on materials and processes issues.

  10. The pultrusion process for structures on advanced aerospace transportation systems

    NASA Technical Reports Server (NTRS)

    Wilson, Maywood L.; Macconochie, Ian O.; Johnson, Gary S.

    1986-01-01

    The pultrusion process, which has the potential for use in the manufacture of structures for aerospace hardware, is described. In this process, reinforcing fibers are pulled continuously through a resin system for wetting and subsequently through a heated die for polymerization. By using this process, fabrication of very long lengths of high strength, lightweight structures with consistently high quality for aerospace applications is possible. The more conventional processes involve hand lay-up, vacuum bagging, autoclaving or oven curing techniques such that lengths of structural elements produced are limited by the lengths of autoclaves or curing ovens. Several types of developmental structural elements are described in which fiberglass, aramid, graphite, and hybrid fiber systems have been used as reinforcements in an epoxy matrix and their flexural properties compared. Reinforcement fibers having tailor-made orientations which achieve tailor-made strength in the pultrusions are described. The potential aerospace applications for the pultruded products are described with advantages cited over conventional hand lay-up methods.

  11. Potential aerospace applications of high temperature superconductors

    NASA Technical Reports Server (NTRS)

    Selim, Raouf

    1994-01-01

    The recent discovery of High Temperature Superconductors (HTS) with superconducting transition temperature, T(sub c), above the boiling point of liquid nitrogen has opened the door for using these materials in new and practical applications. These materials have zero resistance to electric current, have the capability of carrying large currents and as such have the potential to be used in high magnetic field applications. One of the space applications that can use superconductors is electromagnetic launch of payloads to low-earth-orbit. An electromagnetic gun-type launcher can be used in small payload systems that are launched at very high velocity, while sled-type magnetically levitated launcher can be used to launch larger payloads at smaller velocities. Both types of launchers are being studied by NASA and the aerospace industry. The use of superconductors will be essential in any of these types of launchers in order to produce the large magnetic fields required to obtain large thrust forces. Low Temperature Superconductor (LTS) technology is mature enough and can be easily integrated in such systems. As for the HTS, many leading companies are currently producing HTS coils and magnets that potentially can be mass-produced for these launchers. It seems that designing and building a small-scale electromagnetic launcher is the next logical step toward seriously considering this method for launching payloads into low-earth-orbit. A second potential application is the use of HTS to build sensitive portable devices for the use in Non Destructive Evaluation (NDE). Superconducting Quantum Interference Devices (SQUID's) are the most sensitive instruments for measuring changes in magnetic flux. By using HTS in SQUID's, one will be able to design a portable unit that uses liquid nitrogen or a cryocooler pump to explore the use of gradiometers or magnetometers to detect deep cracks or corrosion in structures. A third use is the replacement of Infra-Red (IR) sensor leads on

  12. Materials Control for Aerospace Applications

    NASA Technical Reports Server (NTRS)

    Ferguson, Michael

    2005-01-01

    The distant future of mankind and the ultimate survivability of the human race, as it is known today, will depend on mans' ability to break earthly bonds and establish new territorial positions throughout the universe. Man must therefore be positioned to not only travel to, but also, to readily adapt to numerous and varying environments. For this mass migration across the galaxies nothing is as import to the human race as is NASA's future missions into Low Earth Orbit (LEO), to the moon, and/or Mars. These missions will form the building blocks to eternity for mankind. From these missions, NASA will develop the foundations for these building blocks based on sound engineering and scientific principles, both known and yet to be discovered. The integrity of the program will lead to development, tracking and control of the most basic elements of hardware production: That being development and control of applications of space flight materials. Choosing the right material for design purposes involves many considerations, such as governmental regulations associated with manufacturing operations, both safety of usage and of manufacturing, general material usage requirements, material longevity and performance requirements, material interfacing compatibility and material usage environments. Material performance is subject to environmental considerations in as much as a given material may perform exceptionally well at standard temperatures and pressures while performing poorly under non-standard conditions. These concerns may be found true for materials relative to the extreme temperatures and vacuum gradients of high altitude usage. The only way to assure that flight worthy materials are used in design is through testing. However, as with all testing, it requires both time on schedule and cost to the operation. One alternative to this high cost testing approach is to rely on a materials control system established by NASA. The NASA community relies on the MAPTIS materials

  13. Actively controlled shaft seals for aerospace applications

    NASA Technical Reports Server (NTRS)

    Salant, Richard F.

    1991-01-01

    Actively controlled mechanical seals have recently been developed for industrial use. This study investigates the feasibility of using such seals for aerospace applications. In a noncontacting mechanical seal, the film thickness depends on the geometry of the seal interface. The amount of coning, which is a measure of the radial convergence or divergence of the seal interface, has a primary effect on the film thickness. Active control of the film thickness is established by controlling the coning with a piezoelectric material. A mathematical model has been formulated to predict the performance of an actively controlled mechanical seal.

  14. Lightweight acoustic treatments for aerospace applications

    NASA Astrophysics Data System (ADS)

    Naify, Christina Jeanne

    2011-12-01

    Increase in the use of composites for aerospace applications has the benefit of decreased structural weight, but at the cost of decreased acoustic performance. Stiff, lightweight structures (such as composites) are traditionally not ideal for acoustic insulation applications because of high transmission loss at low frequencies. A need has thus arisen for effective sound insulation materials for aerospace and automotive applications with low weight addition. Current approaches, such as the addition of mass law dominated materials (foams) also perform poorly when scaled to small thickness and low density. In this dissertation, methods which reduce sound transmission without adding significant weight are investigated. The methods presented are intended to be integrated into currently used lightweight structures such as honeycomb sandwich panels and to cover a wide range of frequencies. Layering gasses of differing acoustic impedances on a panel substantially reduced the amount of sound energy transmitted through the panel with respect to the panel alone or an equivalent-thickness single species gas layer. The additional transmission loss derives from successive impedance mismatches at the interfaces between gas layers and the resulting inefficient energy transfer. Attachment of additional gas layers increased the transmission loss (TL) by as much as 17 dB at high (>1 kHz) frequencies. The location and ordering of the gasses with respect to the panel were important factors in determining the magnitude of the total TL. Theoretical analysis using a transfer matrix method was used to calculate the frequency dependence of sound transmission for the different configurations tested. The method accurately predicted the relative increases in TL observed with the addition of different gas layer configurations. To address low-frequency sound insulation, membrane-type locally resonant acoustic materials (LRAM) were fabricated, characterized, and analyzed to understand their

  15. Advanced Hybrid Materials for Aerospace Propulsion Applications (Briefing Charts)

    DTIC Science & Technology

    2013-02-01

    Viewgraph 3. DATES COVERED (From - To) February 2013- April 2013 4. TITLE AND SUBTITLE Advanced hybrid materials for aerospace propulsion applications ...Many material improvements are needed for specific aerospace propulsion applications . Because the industrial community in extremely risk-averse, the...activities focused on inert materials for solid rocket propulsion applications , including the development of alternative high-temperature thermosetting

  16. Optical Information Processing for Aerospace Applications

    NASA Technical Reports Server (NTRS)

    1981-01-01

    Current research in optical processing is reviewed. Its role in future aerospace systems is determined. The development of optical devices and components demonstrates that system concepts can be implemented in practical aerospace configurations.

  17. Application of fracture mechanics and half-cycle theory to the prediction of fatigue life of aerospace structural components

    NASA Technical Reports Server (NTRS)

    Ko, William L.

    1989-01-01

    The service life of aircraft structural components undergoing random stress cycling was analyzed by the application of fracture mechanics. The initial crack sizes at the critical stress points for the fatigue crack growth analysis were established through proof load tests. The fatigue crack growth rates for random stress cycles were calculated using the half-cycle method. A new equation was developed for calculating the number of remaining flights for the structural components. The number of remaining flights predicted by the new equation is much lower than that predicted by the conventional equation. This report describes the application of fracture mechanics and the half-cycle method to calculate the number of remaining flights for aircraft structural components.

  18. Potential teleoperator applications in manned aerospace systems

    NASA Technical Reports Server (NTRS)

    Johnsen, E. G.

    1973-01-01

    The trend of teleoperator development is toward digital computer controlled systems which utilize local sensor-computer-actuator loops to avoid obstacles and to sense manipulator grip-and-slip. The potential applications of advanced teleoperator technology to manned aerospace systems include long manipulator booms to be mounted on the shuttle. These can transfer cargo from the space shuttle and can acquire and retrieve objects in space. Free-flying teleoperators capable of acquiring, inspecting, repairing or refurbishing satellites in orbit are another space application. Another potential application of teleoperator technology is the concept of using an anthropomorphous teleoperator in lieu of man to control aircraft or spacecraft normally controlled by a human pilot.

  19. Lithium-Ion Batteries for Aerospace Applications

    NASA Technical Reports Server (NTRS)

    Surampudi, S.; Halpert, G.; Marsh, R. A.; James, R.

    1999-01-01

    This presentation reviews: (1) the goals and objectives, (2) the NASA and Airforce requirements, (3) the potential near term missions, (4) management approach, (5) the technical approach and (6) the program road map. The objectives of the program include: (1) develop high specific energy and long life lithium ion cells and smart batteries for aerospace and defense applications, (2) establish domestic production sources, and to demonstrate technological readiness for various missions. The management approach is to encourage the teaming of universities, R&D organizations, and battery manufacturing companies, to build on existing commercial and government technology, and to develop two sources for manufacturing cells and batteries. The technological approach includes: (1) develop advanced electrode materials and electrolytes to achieve improved low temperature performance and long cycle life, (2) optimize cell design to improve specific energy, cycle life and safety, (3) establish manufacturing processes to ensure predictable performance, (4) establish manufacturing processes to ensure predictable performance, (5) develop aerospace lithium ion cells in various AH sizes and voltages, (6) develop electronics for smart battery management, (7) develop a performance database required for various applications, and (8) demonstrate technology readiness for the various missions. Charts which review the requirements for the Li-ion battery development program are presented.

  20. Progress in patch repair of aerospace composite structures

    NASA Astrophysics Data System (ADS)

    Hou, Weiguo; Zhang, Weifang; Tang, Qingyun

    2011-11-01

    With the rapid application of the composite structure in the aerospace industry, more load-bearing structures and components are used with composites instead of conventional engineering materials. However, the composite structures are inevitably suffered damages in the complex environment, the composites structures repair become more important in the airplane maintenance. This paper describes the composites patch repair progress. Firstly, the flaws and damages concerned to composite structures are concluded, and also the repair principles are presented. Secondly, the advantages and disadvantages for different repair methods are analyzed, as well as the different bonded repair and their applicability to different structures is discussed. According the recent research in theory and experiment, the scarf repair effects under different parameters are analyzed. Finally, the failure mechanisms of repair structure are discussed, and some prospects are put forward.

  1. Progress in patch repair of aerospace composite structures

    NASA Astrophysics Data System (ADS)

    Hou, Weiguo; Zhang, Weifang; Tang, Qingyun

    2012-04-01

    With the rapid application of the composite structure in the aerospace industry, more load-bearing structures and components are used with composites instead of conventional engineering materials. However, the composite structures are inevitably suffered damages in the complex environment, the composites structures repair become more important in the airplane maintenance. This paper describes the composites patch repair progress. Firstly, the flaws and damages concerned to composite structures are concluded, and also the repair principles are presented. Secondly, the advantages and disadvantages for different repair methods are analyzed, as well as the different bonded repair and their applicability to different structures is discussed. According the recent research in theory and experiment, the scarf repair effects under different parameters are analyzed. Finally, the failure mechanisms of repair structure are discussed, and some prospects are put forward.

  2. Structural Health Management for Future Aerospace Vehicles

    NASA Technical Reports Server (NTRS)

    Prosser, W. H.; Allison, S. G.; Woodard, S. E.; Wincheski, R. A.; Cooper, E. G.; Price, D. C.; Hedley, M.; Prokopenko, M.; Scott, D. A.; Tessler, A.

    2004-01-01

    Structural Health Management (SHM) will be of critical importance to provide the safety, reliability and affordability necessary for the future long duration space missions described in America's Vision for Space Exploration. Long duration missions to the Moon, Mars and beyond cannot be accomplished with the current paradigm of periodic, ground based structural integrity inspections. As evidenced by the Columbia tragedy, this approach is also inadequate for the current Shuttle fleet, thus leading to its initial implementation of on-board SHM sensing for impact detection as part of the return to flight effort. However, future space systems, to include both vehicles as well as structures such as habitation modules, will require an integrated array of onboard in-situ sensing systems. In addition, advanced data systems architectures will be necessary to communicate, store and process massive amounts of SHM data from large numbers of diverse sensors. Further, improved structural analysis and design algorithms will be necessary to incorporate SHM sensing into the design and construction of aerospace structures, as well as to fully utilize these sensing systems to provide both diagnosis and prognosis of structural integrity. Ultimately, structural integrity information will feed into an Integrated Vehicle Health Management (IVHM) system that will provide real-time knowledge of structural, propulsion, thermal protection and other critical systems for optimal vehicle management and mission control. This paper will provide an overview of NASA research and development in the area of SHM as well as to highlight areas of technology improvement necessary to meet these future mission requirements.

  3. Artificial Immune System Approaches for Aerospace Applications

    NASA Technical Reports Server (NTRS)

    KrishnaKumar, Kalmanje; Koga, Dennis (Technical Monitor)

    2002-01-01

    Artificial Immune Systems (AIS) combine a priori knowledge with the adapting capabilities of biological immune system to provide a powerful alternative to currently available techniques for pattern recognition, modeling, design, and control. Immunology is the science of built-in defense mechanisms that are present in all living beings to protect against external attacks. A biological immune system can be thought of as a robust, adaptive system that is capable of dealing with an enormous variety of disturbances and uncertainties. Biological immune systems use a finite number of discrete "building blocks" to achieve this adaptiveness. These building blocks can be thought of as pieces of a puzzle which must be put together in a specific way-to neutralize, remove, or destroy each unique disturbance the system encounters. In this paper, we outline AIS models that are immediately applicable to aerospace problems and identify application areas that need further investigation.

  4. Development of Structural Health Management Technology for Aerospace Vehicles

    NASA Technical Reports Server (NTRS)

    Prosser, W. H.

    2003-01-01

    As part of the overall goal of developing Integrated Vehicle Health Management (IVHM) systems for aerospace vehicles, NASA has focused considerable resources on the development of technologies for Structural Health Management (SHM). The motivations for these efforts are to increase the safety and reliability of aerospace structural systems, while at the same time decreasing operating and maintenance costs. Research and development of SHM technologies has been supported under a variety of programs for both aircraft and spacecraft including the Space Launch Initiative, X-33, Next Generation Launch Technology, and Aviation Safety Program. The major focus of much of the research to date has been on the development and testing of sensor technologies. A wide range of sensor technologies are under consideration including fiber-optic sensors, active and passive acoustic sensors, electromagnetic sensors, wireless sensing systems, MEMS, and nanosensors. Because of their numerous advantages for aerospace applications, most notably being extremely light weight, fiber-optic sensors are one of the leading candidates and have received considerable attention.

  5. Aerospace Flywheel Technology Development for IPACS Applications

    NASA Technical Reports Server (NTRS)

    McLallin, Kerry L.; Jansen, Ralph H.; Fausz, Jerry; Bauer, Robert D.

    2001-01-01

    The National Aeronautics and Space Administration (NASA) and the Air Force Research Laboratory (AFRL) are cooperating under a space act agreement to sponsor the research and development of aerospace flywheel technologies to address mutual future mission needs. Flywheel technology offers significantly enhanced capability or is an enabling technology. Generally these missions are for energy storage and/or integrated power and attitude control systems (IPACS) for mid-to-large satellites in low earth orbit. These missions require significant energy storage as well as a CMG or reaction wheel function for attitude control. A summary description of the NASA and AFRL flywheel technology development programs is provided, followed by specific descriptions of the development plans for integrated flywheel system tests for IPACS applications utilizing both fixed and actuated flywheel units. These flywheel system development tests will be conducted at facilities at AFRL and NASA Glenn Research Center and include participation by industry participants Honeywell and Lockheed Martin.

  6. Development of Sensors for Aerospace Applications

    NASA Technical Reports Server (NTRS)

    Medelius, Pedro

    2005-01-01

    Advances in technology have led to the availability of smaller and more accurate sensors. Computer power to process large amounts of data is no longer the prevailing issue; thus multiple and redundant sensors can be used to obtain more accurate and comprehensive measurements in a space vehicle. The successful integration and commercialization of micro- and nanotechnology for aerospace applications require that a close and interactive relationship be developed between the technology provider and the end user early in the project. Close coordination between the developers and the end users is critical since qualification for flight is time-consuming and expensive. The successful integration of micro- and nanotechnology into space vehicles requires a coordinated effort throughout the design, development, installation, and integration processes

  7. Physics in Aerospace and Military Applications

    NASA Astrophysics Data System (ADS)

    Tat, Hong

    2006-12-01

    Aerospace, which includes both commercial and military applications, provides a wide variety of challenging opportunities in physics. I have worked primarily in the area of sensors with projects including airport baggage scanners and defect detection for the Space Shuttle. In my current role on the Army's Future Combat Systems, we use physical models to predict battlefield sensor performance. This talk will focus on the physical principles involved in modeling electro-optical sensor performance, including the fundamental concept of minimum resolvable contrast and minimum resolvable temperature curves. I will also touch upon my experiences at Boeing and give an overview of the range of physics-related projects at Boeing. Approved for Public Release, Distribution Unlimited, TACOM 15 SEP 2006, case 06-188

  8. Capacitance-based damage detection sensing for aerospace structural composites

    NASA Astrophysics Data System (ADS)

    Bahrami, P.; Yamamoto, N.; Chen, Y.; Manohara, H.

    2014-04-01

    Damage detection technology needs improvement for aerospace engineering application because detection within complex composite structures is difficult yet critical to avoid catastrophic failure. Damage detection is challenging in aerospace structures because not all the damage detection technology can cover the various defect types (delamination, fiber fracture, matrix crack etc.), or conditions (visibility, crack length size, etc.). These defect states are expected to become even more complex with future introduction of novel composites including nano-/microparticle reinforcement. Currently, non-destructive evaluation (NDE) methods with X-ray, ultrasound, or eddy current have good resolutions (< 0.1 mm), but their detection capabilities is limited by defect locations and orientations and require massive inspection devices. System health monitoring (SHM) methods are often paired with NDE technologies to signal out sensed damage, but their data collection and analysis currently requires excessive wiring and complex signal analysis. Here, we present a capacitance sensor-based, structural defect detection technology with improved sensing capability. Thin dielectric polymer layer is integrated as part of the structure; the defect in the structure directly alters the sensing layer's capacitance, allowing full-coverage sensing capability independent of defect size, orientation or location. In this work, capacitance-based sensing capability was experimentally demonstrated with a 2D sensing layer consisting of a dielectric layer sandwiched by electrodes. These sensing layers were applied on substrate surfaces. Surface indentation damage (~1mm diameter) and its location were detected through measured capacitance changes: 1 to 250 % depending on the substrates. The damage detection sensors are light weight, and they can be conformably coated and can be part of the composite structure. Therefore it is suitable for aerospace structures such as cryogenic tanks and rocket

  9. Amplified piezoelectric actuators: from aerospace to underwater applications

    NASA Astrophysics Data System (ADS)

    Bouchilloux, Philippe; Claeyssen, Frank; Le Letty, Ronan

    2004-07-01

    Aerospace and underwater applications typically require actuators capable of large displacements, precise positioning, and fast response times. To meet these requirements, several classes of actuators based on low-voltage piezoelectric materials have been developed, and, in the case of the Amplified Piezoelectric Actuators (APA series), space qualified. The APA actuators offer large displacements (up to 1mm), large deformations (up to 3%), and large forces (up to 1kN) at low electrical power. These actuators can withstand large external forces and have successfully passed severe qualification tests such as centrifugal accelerations and vibration forces encountered during space launch. Aerospace applications of APAs include scientific instrumentation, such as telescopes and microscopes, microsatellite propulsion valves, and structural vibration control. Aeronautical applications include active flap control in aircraft wings and helicopter blades. Underwater applications focus on the silencing of ships, the piezodiagnostic (NDE) of structural defects in pipelines and hulls, and guidance systems of unmanned vehicles. This paper reviews the use of piezoelectric actuators, in particular APAs, in such applications. Qualification results, when available, are presented and discussed.

  10. [Application of lower body negative pressure (LBNP) in aerospace medicine].

    PubMed

    Wu, Ping; Xie, Bao-sheng; Huang, Wei-fen

    2002-06-01

    Effects of LBNP is similar to that produced by gravitational force, especially as a stress factor on the cardiovascular system as has been concerned in the area of aerospace medicine. This paper described experimental equipment, methods and physiological effects of LBNP, especially its application in the area of aerospace medicine. Several aspects for future research were put forward.

  11. Aerospace Applications of Non-Equilibrium Plasma

    NASA Technical Reports Server (NTRS)

    Blankson, Isaiah M.

    2016-01-01

    Nonequilibrium plasma/non-thermal plasma/cold plasmas are being used in a wide range of new applications in aeronautics, active flow control, heat transfer reduction, plasma-assisted ignition and combustion, noise suppression, and power generation. Industrial applications may be found in pollution control, materials surface treatment, and water purification. In order for these plasma processes to become practical, efficient means of ionization are necessary. A primary challenge for these applications is to create a desired non-equilibrium plasma in air by preventing the discharge from transitioning into an arc. Of particular interest is the impact on simulations and experimental data with and without detailed consideration of non-equilibrium effects, and the consequences of neglecting non-equilibrium. This presentation will provide an assessment of the presence and influence of non-equilibrium phenomena for various aerospace needs and applications. Specific examples to be considered will include the forward energy deposition of laser-induced non-equilibrium plasmoids for sonic boom mitigation, weakly ionized flows obtained from pulsed nanosecond discharges for an annular Hall type MHD generator duct for turbojet energy bypass, and fundamental mechanisms affecting the design and operation of novel plasma-assisted reactive systems in dielectric liquids (water purification, in-pipe modification of fuels, etc.).

  12. Optical Information Processing for Aerospace Applications 2

    NASA Technical Reports Server (NTRS)

    Stermer, R. L. (Compiler)

    1984-01-01

    Current research in optical processing, and determination of its role in future aerospace systems was reviewed. It is shown that optical processing offers significant potential for aircraft and spacecraft control, pattern recognition, and robotics. It is demonstrated that the development of optical devices and components can be implemented in practical aerospace configurations.

  13. Thermal oxidation induced degradation of carbon fiber reinforced composites and carbon nanotube sheet enhanced fiber/matrix interface for high temperature aerospace structural applications

    NASA Astrophysics Data System (ADS)

    Haque, Mohammad Hamidul

    Recent increase in the use of carbon fiber reinforced polymer matrix composite, especially for high temperature applications in aerospace primary and secondary structures along with wind energy and automotive industries, have generated new challenges to predict its failure mechanisms and service life. This dissertation reports the experimental study of a unidirectional carbon fiber reinforced bismaleimide (BMI) composites (CFRC), an excellent candidate for high temperature aerospace components, undergoing thermal oxidation at 260 °C in air for over 3000 hours. The key focus of the work is to investigate the mechanical properties of the carbon fiber BMI composite subjected to thermal aging in three key aspects - first, studying its bulk flexural properties (in macro scale), second, characterizing the crack propagation along the fiber direction, representing the interfacial bonding strength between fiber and matrix (in micro scale), and third, introducing nano-structured materials to modify the interface (in nano scale) between the carbon fiber and BMI resin and mechanical characterization to study its influence on mitigating the aging effect. Under the first category, weight loss and flexural properties have been monitored as the oxidation propagates through the fiber/matrix interface. Dynamic mechanical analysis and micro-computed tomography analysis have been performed to analyze the aging effects. In the second category, the long-term effects of thermal oxidation on the delamination (between the composite plies) and debonding (between fiber and matrix) type fracture toughness have been characterized by preparing two distinct types of double cantilever beam specimens. Digital image correlation has been used to determine the deformation field and strain distribution around the crack propagation path. Finally the resin system and the fiber/matrix interface have been modified using nanomaterials to mitigate the degradations caused by oxidation. Nanoclay modified

  14. High-Temperature Strain Sensing for Aerospace Applications

    NASA Technical Reports Server (NTRS)

    Piazza, Anthony; Richards, Lance W.; Hudson, Larry D.

    2008-01-01

    Thermal protection systems (TPS) and hot structures are utilizing advanced materials that operate at temperatures that exceed abilities to measure structural performance. Robust strain sensors that operate accurately and reliably beyond 1800 F are needed but do not exist. These shortcomings hinder the ability to validate analysis and modeling techniques and hinders the ability to optimize structural designs. This presentation examines high-temperature strain sensing for aerospace applications and, more specifically, seeks to provide strain data for validating finite element models and thermal-structural analyses. Efforts have been made to develop sensor attachment techniques for relevant structural materials at the small test specimen level and to perform laboratory tests to characterize sensor and generate corrections to apply to indicated strains. Areas highlighted in this presentation include sensors, sensor attachment techniques, laboratory evaluation/characterization of strain measurement, and sensor use in large-scale structures.

  15. Large stable aluminum optics for aerospace applications

    NASA Astrophysics Data System (ADS)

    Vukobratovich, Daniel; Schaefer, John P.

    2011-09-01

    Aluminum mirrors offer the advantages of lower cost, shorter fabrication time, more rugged mounting, and same material athermalization when compared to classical glass mirrors. In the past these advantages were offset by controversial dimensional stability and high surface scatter, limiting applications to IR systems. Raytheon developed processes to improve long term stability, and reduce surface scatter. Six 380 mm aperture aluminum mirrors made using these processes showed excellent stability, with figure changes of less than 0.01 wave RMS(1 wave = 633 nm) when cycled 10 times between -51 and +71 deg. C. The VQ process developed at ELCAN reduces surface scatter in bare aluminum mirrors to below 20 angstroms RMS, and has been used in thousands of production mirrors up to 300 mm aperture. These processes were employed in the fabrication of two lightweight single arch 600 mm aluminum mirrors. The two mirrors were produced in four months, with a mounted surface figure of 0.22 waves RMS and surface roughness of 20 angstroms. Mounted fundamental frequency was 218 Hz, and no figure distortion was observed at preload levels four times higher than design. Subsequently the mirrors performed well when subjected to severe environmental loadings in a Raytheon test system. This technology is being extended to ultra-lightweight sandwich mirrors, which are competitive with other material technologies used in advanced aerospace applications such as high-altitude UAV surveillance systems and satellite optics.

  16. Applications of aerospace technology to petroleum exploration. Volume 2: Appendices

    NASA Technical Reports Server (NTRS)

    Jaffe, L. D.

    1976-01-01

    Participants in the investigation of problem areas in oil exploration are listed and the data acquisition methods used to determine categories to be studied are described. Specific aerospace techniques applicable to the tasks identified are explained and their costs evaluated.

  17. Lessons learned from modal testing of aerospace structures

    NASA Astrophysics Data System (ADS)

    Hunt, David L.; Brillhart, Ralph D.

    1993-02-01

    The primary factors affecting the accuracy and the time required to perform modal tests on aerospace structures are discussed, and the lessons learned from modal tests performed over the past 15 yrs are examined. Case histories of modal testing on aerospace structures are reviewed, including the Galileo satellite and the Space Shuttle solid rocket motor and test stand. Currently recommended approaches to the modal testing are addressed.

  18. NASA-UVA light aerospace alloy and structures technology program

    NASA Technical Reports Server (NTRS)

    Gangloff, Richard P.; Haviland, John K.; Herakovich, Carl T.; Pilkey, Walter D.; Pindera, Marek-Jerzy; Stoner, Glenn E.; Swanson, Robert E.; Thornton, Earl A.; Wawner, Franklin E., Jr.; Wert, John A.

    1990-01-01

    The objective of the Light Aerospace Alloy and Structures Technology Program is to conduct interdisciplinary graduate student research on the performance of next generation, light weight aerospace alloys, composites, and associated thermal gradient structures. Individual technical objectives are established for each project. Efforts aim to produce basic understanding of material behavior, monolithic and composite alloys, processing methods, solid and mechanics analyses, measurement advances, and a pool of educated graduate students. Progress is reported for 11 areas of study.

  19. Biomimetic optical sensor for aerospace applications

    NASA Astrophysics Data System (ADS)

    Frost, Susan A.; Gorospe, George E.; Wright, Cameron H. G.; Barrett, Steven F.

    2015-05-01

    We report on a fiber optic sensor based on the physiological aspects of the eye and vision-related neural layers of the common housefly (Musca domestica) that has been developed and built for aerospace applications. The intent of the research is to reproduce select features from the fly's vision system that are desirable in image processing, including high functionality in low-light and low-contrast environments, sensitivity to motion, compact size, lightweight, and low power and computation requirements. The fly uses a combination of overlapping photoreceptor responses that are well approximated by Gaussian distributions and neural superposition to detect image features, such as object motion, to a much higher degree than just the photoreceptor density would imply. The Gaussian overlap in the biomimetic sensor comes from the front-end optical design, and the neural superposition is accomplished by subsequently combining the signals using analog electronics. The fly eye sensor is being developed to perform real-time tracking of a target on a flexible aircraft wing experiencing bending and torsion loads during flight. We report on results of laboratory experiments using the fly eye sensor to sense a target moving across its field of view.

  20. Finite element simulation of adaptive aerospace structures with SMA actuators

    NASA Astrophysics Data System (ADS)

    Frautschi, Jason; Seelecke, Stefan

    2003-07-01

    The particular demands of aerospace engineering have spawned many of the developments in the field of adaptive structures. Shape memory alloys are particularly attractive as actuators in these types of structures due to their large strains, high specific work output and potential for structural integration. However, the requisite extensive physical testing has slowed development of potential applications and highlighted the need for a simulation tool for feasibility studies. In this paper we present an implementation of an extended version of the M'ller-Achenbach SMA model into a commercial finite element code suitable for such studies. Interaction between the SMA model and the solution algorithm for the global FE equations is thoroughly investigated with respect to the effect of tolerances and time step size on convergence, computational cost and accuracy. Finally, a simulation of a SMA-actuated flexible trailing edge of an aircraft wing modeled with beam elements is presented.

  1. Aerospace Applications Of High Temperature Superconductivity

    NASA Astrophysics Data System (ADS)

    Anderson, W. W.

    1988-05-01

    The existence of superconductors with TcOOK (which implies device operating temper-atures the order of Top ≍45K) opens up a variety of potential applications within the aerospace/defense industry. This is partly due to the existence of well developed cooler technologies to reach this temperature regime and partly due to the present operation of some specialized components at cryogenic temperatures. In particular, LWIR focal planes may operate at 10K with some of the signal processing electronics at an intermediate temperature of 40K. Addition of high Tc superconducting components in the latter system may be "free" in the sense of additional system complexity required. The established techniques for cooling in the 20K to 50K temperature regime are either open cycle, expendable material (stored gas with Joule-Thomson expansion, liquid cryogen or solid cryogen) or mechanical refrigerators (Stirling cycle, Brayton cycle or closed cycle Joule-Thomson). The high Tc materials may also contribute to the development of coolers through magnetically levitated bearings or providing the field for a stage of magnetic refrigeration. The discovery of materials with Tc, 90K has generated a veritable shopping list of applications. The superconductor properties which are of interest for applications are (1) zero resistance, (2) Meissner effect, (3) phase coherence and (4) existence of an energy gap. The zero resistance property is significant in the development of high field magnets requiring neglible power to maintain the field. In addition to the publicized applications to rail guns and electromagnetic launcher, we can think of space born magnets for charged particle shielding or whistler mode propagation through a plasma sheath. Conductor losses dominate attenuation and dispersion in microstrip transmission lines. While the surface impedance of a superconductor is non vanishing, significant improvements in signal transmission may be obtained. The Meissner effect may be utilized

  2. Advances in Computational Stability Analysis of Composite Aerospace Structures

    SciTech Connect

    Degenhardt, R.; Araujo, F. C. de

    2010-09-30

    European aircraft industry demands for reduced development and operating costs. Structural weight reduction by exploitation of structural reserves in composite aerospace structures contributes to this aim, however, it requires accurate and experimentally validated stability analysis of real structures under realistic loading conditions. This paper presents different advances from the area of computational stability analysis of composite aerospace structures which contribute to that field. For stringer stiffened panels main results of the finished EU project COCOMAT are given. It investigated the exploitation of reserves in primary fibre composite fuselage structures through an accurate and reliable simulation of postbuckling and collapse. For unstiffened cylindrical composite shells a proposal for a new design method is presented.

  3. Actively controlled shaft seals for aerospace applications

    NASA Technical Reports Server (NTRS)

    Salant, Richard F.

    1994-01-01

    This study experimentally investigates an actively controlled mechanical seal for aerospace applications. The seal of interest is a gas seal, which is considerably more compact than previous actively controlled mechanical seals that were developed for industrial use. In a mechanical seal, the radial convergence of the seal interface has a primary effect on the film thickness. Active control of the film thickness is established by controlling the radial convergence of the seal interface with piezoelectric actuator. An actively controlled mechanical seal was initially designed and evaluated using a mathematical model. Based on these results, a seal was fabricated and tested under laboratory conditions. The seal was tested with both helium and air, at rotational speeds up to 3770 rad/sec, and at sealed pressures as high as 1.48 x 10(exp 6) Pa. The seal was operated with both manual control and with a closed-loop control system that used either the leakage rate or face temperature as the feedback. The output of the controller was the voltage applied to the piezoelectric actuator. The seal operated successfully for both short term tests (less than one hour) and for longer term tests (four hours) with a closed-loop control system. The leakage rates were typically 5-15 slm (standard liters per minute), and the face temperatures were generally maintained below 100 C. When leakage rate was used as the feedback signal, the setpoint leakage rate was typically maintained within 1 slm. However, larger deviations occurred during sudden changes in sealed pressure. When face temperature was used as the feedback signal, the setpoint face temperature was generally maintained within 3 C, with larger deviations occurring when the sealed pressure changed suddenly.

  4. Parameter estimation of large flexible aerospace structures with application to the control of the Maypole Deployable Reflector

    NASA Technical Reports Server (NTRS)

    Balas, M. J.

    1981-01-01

    Systems such as the Maypole deployable reflector have a distributed parameter nature. The flexible column and hoop structure and the circular antenna of 30-100 meter diameter which it supports are described by partial, rather than ordinary, differential equations. Progress completed in reduced order modelling andd controller design and digital parameter estimation and control is summarized. Topics covered include depolyment and on-orbit operation; quasi-static (steady state) operation; dynamic distributed parameter system; autoregressive moving average identification; frequency domain procedures; direct or implicit active control; adaptive observers; parameter estimation using a linear reinforcement learning factor; feedback control; and reduced order modeling for nonlinear systems.

  5. Environmentally friendly power sources for aerospace applications

    NASA Astrophysics Data System (ADS)

    Lapeña-Rey, Nieves; Mosquera, Jonay; Bataller, Elena; Ortí, Fortunato; Dudfield, Christopher; Orsillo, Alessandro

    between the two power sources [N. Lapeña-Rey, J. Mosquera, E. Bataller, F. Ortí, SAE 2007 Aerotech Congress & Exhibition, 2007 (Publication number: 2007-01-3906)]. The demonstrator airplane constitutes an example of the successful implementation of novel clean power sources in aviation. The detailed description of the airplane and its subsystems is given elsewhere [N. Lapeña-Rey, J. Mosquera, E. Bataller, F. Ortí, SAE 2007 Aerotech Congress & Exhibition, 2007 (Publication number: 2007-01-3906)]. This paper focuses specially on the power sources design and pre-flight tests giving special attention to those requirements derived from aerospace applications.

  6. PMR polyimide composites for aerospace applications

    NASA Technical Reports Server (NTRS)

    Serafini, T. T.

    1982-01-01

    Fiber reinforced PMR polyimides are finding increased acceptance as engineering materials for high performance structural applications. Prepreg materials based on this novel class of highly processable, high temperature resistant polyimides, are commercially available and the PMR concept was incorporated in several industrial applications. The status of PMR polyimides is reviewed. Emphasis is given to the chemistry, processing, and applications of the first generation PMR polyimides known as PMR-15.

  7. Transient thermographic technique for NDI of aerospace composite structures

    NASA Astrophysics Data System (ADS)

    McCullough, Robert W.

    2004-04-01

    Transient thermography is well established as a capable tool for non-destructive testing (NDT) in aerospace composite structures (see for example Favro, et. al 1995). The basic process involves altering the steady state thermal condition of a structure by adding or removing thermal energy (heat) and then observing the transient temperature patterns on a surface by means of a sensitive infrared imaging system. Many techniques for heat addition have been tried including most commonly convective and radiative transfer to external surfaces. As an NDT technique it is especially appealing for composite structures whose constituent thermal properties may vary considerably leading to interesting and illuminating transient patterns (Favro, et. al. 1993). We have developed a novel application of transient thermography with an application to detecting bonding flaws in boron/epoxy skinned aluminum honeycomb composite structures as found for example in the F14 and F15 aircraft. The technique described below uses induction to selectively heat the structure near the flaw region and has potential benefits in a range of applications.

  8. Application of Smart Solid State Sensor Technology in Aerospace Applications

    NASA Technical Reports Server (NTRS)

    Hunter, Gary W.; Xu, Jennifer C.; Dungan, L.K.; Makel, D.; Ward, B.; Androjna, D.

    2008-01-01

    Aerospace applications require a range of chemical sensing technologies to monitor conditions in both space vehicles and aircraft operations. One example is the monitoring of oxygen. For example, monitoring of ambient oxygen (O2) levels is critical to ensuring the health, safety, and performance of humans living and working in space. Oxygen sensors can also be incorporated in detection systems to determine if hazardous leaks are occurring in space propulsion systems and storage facilities. In aeronautic applications, O2 detection has been investigated for fuel tank monitoring. However, as noted elsewhere, O2 is not the only species of interest in aerospace applications with a wide range of species of interest being relevant to understand an environmental or vehicle condition. These include combustion products such as CO, HF, HCN, and HCl, which are related to both the presence of a fire and monitoring of post-fire clean-up operations. This paper discusses the development of an electrochemical cell platform based on a polymer electrolyte, NAFION, and a three-electrode configuration. The approach has been to mature this basic platform for a range of applications and to test this system, combined with "Lick and Stick" electronics, for its viability to monitor an environment related to astronaut crew health and safety applications with an understanding that a broad range of applications can be addressed with a core technology.

  9. Study on application of aerospace technology to improve surgical implants

    NASA Technical Reports Server (NTRS)

    Johnson, R. E.; Youngblood, J. L.

    1982-01-01

    The areas where aerospace technology could be used to improve the reliability and performance of metallic, orthopedic implants was assessed. Specifically, comparisons were made of material controls, design approaches, analytical methods and inspection approaches being used in the implant industry with hardware for the aerospace industries. Several areas for possible improvement were noted such as increased use of finite element stress analysis and fracture control programs on devices where the needs exist for maximum reliability and high structural performance.

  10. Aerospace applications of high temperature superconductivity

    NASA Technical Reports Server (NTRS)

    Connolly, D. J.; Heinen, V. O.; Aron, P. R.; Lazar, J.; Romanofsky, Robert R.

    1990-01-01

    A review is presented of all the applications that are part of the NASA program to develop space technology capitalizing on the potential benefit of high temperature superconducting materials. The applications in three major areas are being pursued: sensors and cryogenic systems, space communications, and propulsion and power systems. This review places emphasis on space communications applications and the propulsion and power applications. It is concluded that the power and propulsion applications will eventually be limited by structural considerations rather than by the availability of suitable superconductors. A cursory examination of structural limitations implied by the virial theorem suggested that there is an upper limit to the size of high field magnetic systems that are feasible in space.

  11. Aerospace Applications of Magnetic Suspension Technology, part 1

    NASA Technical Reports Server (NTRS)

    Groom, Nelson J. (Editor); Britcher, Colin P. (Editor)

    1991-01-01

    Papers presented at the conference on aerospace applications of magnetic suspension technology are compiled. The following subject areas are covered: pointing and isolation systems; microgravity and vibration isolation; bearing applications; wind tunnel model suspension systems; large gap magnetic suspension systems; control systems; rotating machinery; science and application of superconductivity; and sensors.

  12. Ethernet for Aerospace Applications - Ethernet Heads for the Skies

    NASA Technical Reports Server (NTRS)

    Grams, Paul R.

    2015-01-01

    One of the goals of aerospace applications is to reduce the cost and complexity of avionic systems. Ethernet is a highly scalable, flexible, and popular protocol. The aerospace market is large, with a forecasted production of over 50,000 turbine-powered aircraft valued at $1.7 trillion between 2012 and 2022. Boeing estimates demand for commercial aircraft by 2033 to total over 36,000 with a value of over $5 trillion. In 2014 US airlines served over 750 million passengers and this is growing over 2% yearly. Electronic fly-by-wire is now used for all airliners and high performance aircraft. Although Ethernet has been widely used for four decades, its use in aerospace applications is just beginning to become common. Ethernet is the universal solution in commercial networks because of its high bandwidths, lower cost, openness, reliability, maintainability, flexibility, and interoperability. However, when Ethernet was designed applications with time-critical, safety relevant and deterministic requirements were not given much consideration. Many aerospace applications use a variety of communication architectures that add cost and complexity. Some of them are SpaceWire, MIL-STD-1553, Avionics Full Duplex Switched Ethernet (AFDX), and Time-Triggered Ethernet (TTE). Aerospace network designers desire to decrease the number of networks to reduce cost and effort while improving scalability, flexibility, openness, maintainability, and reliability. AFDX and TTE are being considered more for critical aerospace systems because they provide redundancy, failover protection, guaranteed timing, and frame priority and are based on Ethernet IEEE 802.3. This paper explores the use of AFDX and TTE for aerospace applications.

  13. Actively Controlled Shaft Seals for Aerospace Applications

    NASA Technical Reports Server (NTRS)

    Salant, Richard F.; Wolff, Paul

    1995-01-01

    This study experimentally investigates an actively controlled mechanical seal for aerospace applications. The seal of interest is a gas seal, which is considerably more compact than previous actively controlled mechanical seals that were developed for industrial use. In a mechanical seal, the radial convergence of the seal interface has a primary effect on the film thickness. Active control of the film thickness is established by controlling the radial convergence of the seal interface with a piezoelectric actuator. An actively controlled mechanical seal was initially designed and evaluated using a mathematical model. Based on these results, a seal was fabricated and tested under laboratory conditions. The seal was tested with both helium and air, at rotational speeds up to 3770 rad/sec, and at sealed pressures as high as 1.48 x 10(exp 6) Pa. The seal was operated with both manual control and with a closed-loop control system that used either the leakage rate or face temperature as the feedback. The output of the controller was the voltage applied to the piezoelectric actuator. The seal operated successfully for both short term tests (less than one hour) and for longer term tests (four hours) with a closed-loop control system. The leakage rates were typically 5-15 slm (standard liters per minute), and the face temperatures were generally maintained below 100C. When leakage rate was used as the feedback signal, the setpoint leakage rate was typically maintained within 1 slm. However, larger deviations occurred during sudden changes in sealed pressure. When face temperature was used as the feedback signal, the setpoint face temperature was generally maintained within 3 C, with larger deviations occurring when the sealed pressure changes suddenly. the experimental results were compared to the predictions from the mathematical model. The model was successful in predicting the trends in leakage rate that occurred as the balance ratio and sealed pressure changed

  14. Actively controlled shaft seals for aerospace applications

    NASA Astrophysics Data System (ADS)

    Salant, Richard F.

    1995-07-01

    This study experimentally investigates an actively controlled mechanical seal for aerospace applications. The seal of interest is a gas seal, which is considerably more compact than previous actively controlled mechanical seals that were developed for industrial use. In a mechanical seal, the radial convergence of the seal interface has a primary effect on the film thickness. Active control of the film thickness is established by controlling the radial convergence of the seal interface with a piezoelectric actuator. An actively controlled mechanical seal was initially designed and evaluated using a mathematical model. Based on these results, a seal was fabricated and tested under laboratory conditions. The seal was tested with both helium and air, at rotational speeds up to 3770 rad/sec, and at sealed pressures as high as 1.48 x 10(exp 6) Pa. The seal was operated with both manual control and with a closed-loop control system that used either the leakage rate or face temperature as the feedback. The output of the controller was the voltage applied to the piezoelectric actuator. The seal operated successfully for both short term tests (less than one hour) and for longer term tests (four hours) with a closed-loop control system. The leakage rates were typically 5-15 slm (standard liters per minute), and the face temperatures were generally maintained below 100C. When leakage rate was used as the feedback signal, the setpoint leakage rate was typically maintained within 1 slm. However, larger deviations occurred during sudden changes in sealed pressure. When face temperature was used as the feedback signal, the setpoint face temperature was generally maintained within 3 C, with larger deviations occurring when the sealed pressure changes suddenly. the experimental results were compared to the predictions from the mathematical model. The model was successful in predicting the trends in leakage rate that occurred as the balance ratio and sealed pressure changed

  15. A critical review of nanotechnologies for composite aerospace structures

    NASA Astrophysics Data System (ADS)

    Kostopoulos, Vassilis; Masouras, Athanasios; Baltopoulos, Athanasios; Vavouliotis, Antonios; Sotiriadis, George; Pambaguian, Laurent

    2017-03-01

    The past decade extensive efforts have been invested in understanding the nano-scale and revealing the capabilities offered by nanotechnology products to structural materials. Integration of nano-particles into fiber composites concludes to multi-scale reinforced composites and has opened a new wide range of multi-functional materials in industry. In this direction, a variety of carbon based nano-fillers has been proposed and employed, individually or in combination in hybrid forms, to approach the desired performance. Nevertheless, a major issue faced lately more seriously due to the interest of industry is on how to incorporate these nano-species into the final composite structure through existing manufacturing processes and infrastructure. This interest originates from several industrial applications needs that request the development of new multi-functional materials which combine enhanced mechanical, electrical and thermal properties. In this work, an attempt is performed to review the most representative processes and related performances reported in literature and the experience obtained on nano-enabling technologies of fiber composite materials. This review focuses on the two main composite manufacturing technologies used by the aerospace industry; Prepreg/Autoclave and Resin Transfer technologies. It addresses several approaches for nano-enabling of composites for these two routes and reports latest achieved results focusing on performance of nano-enabled fiber reinforced composites extracted from literature. Finally, this review work identifies the gap between available nano-technology integration routes and the established industrial composite manufacturing techniques and the challenges to increase the Technology Readiness Level to reach the demands for aerospace industry applications.

  16. A critical review of nanotechnologies for composite aerospace structures

    NASA Astrophysics Data System (ADS)

    Kostopoulos, Vassilis; Masouras, Athanasios; Baltopoulos, Athanasios; Vavouliotis, Antonios; Sotiriadis, George; Pambaguian, Laurent

    2016-07-01

    The past decade extensive efforts have been invested in understanding the nano-scale and revealing the capabilities offered by nanotechnology products to structural materials. Integration of nano-particles into fiber composites concludes to multi-scale reinforced composites and has opened a new wide range of multi-functional materials in industry. In this direction, a variety of carbon based nano-fillers has been proposed and employed, individually or in combination in hybrid forms, to approach the desired performance. Nevertheless, a major issue faced lately more seriously due to the interest of industry is on how to incorporate these nano-species into the final composite structure through existing manufacturing processes and infrastructure. This interest originates from several industrial applications needs that request the development of new multi-functional materials which combine enhanced mechanical, electrical and thermal properties. In this work, an attempt is performed to review the most representative processes and related performances reported in literature and the experience obtained on nano-enabling technologies of fiber composite materials. This review focuses on the two main composite manufacturing technologies used by the aerospace industry; Prepreg/Autoclave and Resin Transfer technologies. It addresses several approaches for nano-enabling of composites for these two routes and reports latest achieved results focusing on performance of nano-enabled fiber reinforced composites extracted from literature. Finally, this review work identifies the gap between available nano-technology integration routes and the established industrial composite manufacturing techniques and the challenges to increase the Technology Readiness Level to reach the demands for aerospace industry applications.

  17. A Hazardous Gas Detection System for Aerospace and Commercial Applications

    NASA Technical Reports Server (NTRS)

    Hunter, G. W.; Neudeck, P. G.; Chen, L. - Y.; Makel, D. B.; Liu, C. C.; Wu, Q. H.; Knight, D.

    1998-01-01

    The detection of explosive conditions in aerospace propulsion applications is important for safety and economic reasons. Microfabricated hydrogen, oxygen, and hydrocarbon sensors as well as the accompanying hardware and software are being developed for a range of aerospace safety applications. The development of these sensors is being done using MEMS (Micro ElectroMechanical Systems) based technology and SiC-based semiconductor technology. The hardware and software allows control and interrogation of each sensor head and reduces accompanying cabling through multiplexing. These systems are being applied on the X-33 and on an upcoming STS-95 Shuttle mission. A number of commercial applications are also being pursued. It is concluded that this MEMS-based technology has significant potential to reduce costs and increase safety in a variety of aerospace applications.

  18. A Hazardous Gas Detection System for Aerospace and Commercial Applications

    NASA Technical Reports Server (NTRS)

    Hunter, G. W.; Neudeck, P. G.; Chen, L.-Y.; Makel, D. B.; Liu, C. C.; Wu, Q. H.; Knight, D.

    1998-01-01

    The detection of explosive conditions in aerospace propulsion applications is important for safety and economic reasons. Microfabricated hydrogen, oxygen, and hydrocarbon sensors as well as the accompanying hardware and software are being, developed for a range of aerospace safety applications. The development of these sensors is being done using MEMS (Micro ElectroMechanical Systems) based technology and SiC-based semiconductor technology. The hardware and software allows control and interrocation of each sensor head and reduces accompanying cabling through multiplexing. These systems are being, applied on the X-33 and on an upcoming STS-95 Shuttle mission. A number of commercial applications are also being pursued. It is concluded that this MEMS-based technology has significant potential to reduce costs and increase safety in a variety of aerospace applications.

  19. A standardized diode cryogenic temperature sensor for aerospace applications

    NASA Astrophysics Data System (ADS)

    Courts, Samuel Scott

    2016-03-01

    The model DT-670-SD cryogenic diode temperature sensor, manufactured by Lake Shore Cryotronics, Inc. has been used on numerous aerospace space missions since its introduction nearly 15 years ago. While the sensing element is a diode, it is operated in a non-standard manner when used as a temperature sensor over the 1.4-500 K temperature range. For this reason, the NASA and MIL-type test and performance standards designed to ensure high reliability of diode aerospace parts don't properly define the inspection and test protocol for the DT-670-SD temperature sensor as written. This requires each aerospace application to develop unique test and inspection protocols for the project, typically for a small number of sensors, resulting in expensive sensors with a long lead time. With over 30 years of experience in supplying cryogenic temperature sensors for aerospace applications, Lake Shore has developed screening and qualification inspection and test protocols to provide "commercial off-the-shelf (COTS)" DT-670-SD temperature sensors that should meet the requirements of most high-reliability applications including aerospace. Parts from acceptance and qualified lots will be available at a base sensor level with the ability to specify an interchangeability tolerance, calibration range, mounting adaptor, and/or lead extension for final configuration. This work presents details of this acceptance and qualification inspection and test protocol as well as performance characteristics of the DT-670-SD cryogenic temperature sensors when inspected and tested to this protocol.

  20. Capillary Pumped Loops for aerospace application

    NASA Astrophysics Data System (ADS)

    Gottschlich, Joseph M.

    1989-09-01

    The Capillary Pumped Loop (CPL) is a two-phase aerospace thermal transport system with many advantageous performance characteristics. While retaining the passive nature of the heat pipe, it has demonstrated an order of magnitude greater thermal transport capacity over high performance arterial heat pipes. In this survey paper, the CPL is described and its brief history discussed. A postulated analytical design model based on thermodynamic principles is presented. Both demonstrated and potential performance advantages are given. Finally, opportunities for future research are suggested.

  1. Optical micromachined pressure sensor for aerospace applications

    NASA Astrophysics Data System (ADS)

    Angelidis, Diogenes; Parsons, Philip

    1992-08-01

    An optical pressure sensor has been designed using silicon micromachining technology. A resonant silicon beam is mounted above a diaphragm and its resonant frequency changes with applied pressure. The sensor is temperature compensated by way of a second pressure-insensitive resonator. Both resonators are optically addressed via the same optical fiber. The sensor is designed to give an overall accuracy of 0.5 percent full-scale pressure, which is currently between 130 kPa or 3 MPa. Optical technology allows the optical pressure sensor to operate in a harsh aerospace environment where electronic pressure sensors cannot survive.

  2. High Temperature Polymer Film Dielectrics for Aerospace Power Conditioning Capacitor Applications

    DTIC Science & Technology

    2008-10-01

    AFRL-RZ-WP-TP-2010-2128 HIGH TEMPERATURE POLYMER FILM DIELECTRICS FOR AEROSPACE POWER CONDITIONING CAPACITOR APPLICATIONS (Postprint...AND SUBTITLE HIGH TEMPERATURE POLYMER FILM DIELECTRICS FOR AEROSPACE POWER CONDITIONING CAPACITOR APPLICATIONS (Postprint) 5a. CONTRACT NUMBER...development of compact capacitors which are thermally robust for operation in a variety of aerospace power conditioning applications. While such applications

  3. Advanced aerospace composite material structural design using artificial intelligent technology

    SciTech Connect

    Sun, S.H.; Chen, J.L.; Hwang, W.C.

    1993-12-31

    Due to the complexity in the prediction of property and behavior, composite material has not substituted for metal widely yet, though it has high specific-strength and high specific-modulus that are more important in the aerospace industry. In this paper two artificial intelligent techniques, the expert systems and neural network technology, were introduced to the structural design of composite material. Expert System which has good ability in symbolic processing can helps us to solve problem by saving experience and knowledge. It is, therefore, a reasonable way to combine expert system technology to tile composite structural design. The development of a prototype expert system to help designer during the process of composite structural design is presented. Neural network is a network similar to people`s brain that can simulate the thinking way of people and has the ability of learning from the training data by adapting the weights of network. Because of the bottleneck in knowledge acquisition processes, the application of neural network and its learning ability to strength design of composite structures are presented. Some examples are in this paper to demonstrate the idea.

  4. Titanium/beryllium laminates - Fabrication, mechanical properties, and potential aerospace applications

    NASA Technical Reports Server (NTRS)

    Chamis, C. C.; Lark, R. F.

    1978-01-01

    The paper describes an investigation to assess the fabricability, mechanical properties, and possible aerospace applications of adhesively-bonded titanium/beryllium Tiber laminates. The results of the investigation indicate that structural laminates can be made which have: a modulus of elasticity comparable to steel, fracture strength comparable to the yield strength of titanium, density comparable to aluminum, impact resistance comparable to titanium, and little or no notch sensitivity. These laminates can have stiffness and weight advantages over other materials, including advanced fiber composites, in some aerospace applications where buckling resistance, vibration frequencies, and weight considerations control the design.

  5. Stochastic Simulation Tool for Aerospace Structural Analysis

    NASA Technical Reports Server (NTRS)

    Knight, Norman F.; Moore, David F.

    2006-01-01

    Stochastic simulation refers to incorporating the effects of design tolerances and uncertainties into the design analysis model and then determining their influence on the design. A high-level evaluation of one such stochastic simulation tool, the MSC.Robust Design tool by MSC.Software Corporation, has been conducted. This stochastic simulation tool provides structural analysts with a tool to interrogate their structural design based on their mathematical description of the design problem using finite element analysis methods. This tool leverages the analyst's prior investment in finite element model development of a particular design. The original finite element model is treated as the baseline structural analysis model for the stochastic simulations that are to be performed. A Monte Carlo approach is used by MSC.Robust Design to determine the effects of scatter in design input variables on response output parameters. The tool was not designed to provide a probabilistic assessment, but to assist engineers in understanding cause and effect. It is driven by a graphical-user interface and retains the engineer-in-the-loop strategy for design evaluation and improvement. The application problem for the evaluation is chosen to be a two-dimensional shell finite element model of a Space Shuttle wing leading-edge panel under re-entry aerodynamic loading. MSC.Robust Design adds value to the analysis effort by rapidly being able to identify design input variables whose variability causes the most influence in response output parameters.

  6. Puncture Self-Healing Polymers for Aerospace Applications

    NASA Technical Reports Server (NTRS)

    Gordon, Keith L.; Penner, Ronald K.; Bogert, Phil B.; Yost, W. T.; Siochi, Emilie J.

    2011-01-01

    Space exploration launch costs on the order of $10K per pound provide ample incentive to seek innovative, cost-effective ways to reduce structural mass without sacrificing safety and reliability. Damage-tolerant structural systems can provide a route to avoiding weight penalty while enhancing vehicle safety and reliability. Self-healing polymers capable of spontaneous puncture repair show great promise to mitigate potentially catastrophic damage from events such as micrometeoroid penetration. Effective self-repair requires these materials to heal instantaneously following projectile penetration while retaining structural integrity. Poly(ethylene-co-methacrylic acid) (EMMA), also known as Surlyn is an ionomer-based copolymer that undergoes puncture reversal (self-healing) following high impact puncture at high velocities. However EMMA is not a structural engineering polymer, and will not meet the demands of aerospace applications requiring self-healing engineering materials. Current efforts to identify candidate self-healing polymer materials for structural engineering systems are reported. Rheology, high speed thermography, and high speed video for self-healing semi-crystalline and amorphous polymers will be reported.

  7. Research and Development of Rapid Design Systems for Aerospace Structure

    NASA Technical Reports Server (NTRS)

    Schaeffer, Harry G.

    1999-01-01

    This report describes the results of research activities associated with the development of rapid design systems for aerospace structures in support of the Intelligent Synthesis Environment (ISE). The specific subsystems investigated were the interface between model assembly and analysis; and, the high performance NASA GPS equation solver software system in the Windows NT environment on low cost high-performance PCs.

  8. An overview of interferometric metrology and NDT techniques and applications for the aerospace industry

    NASA Astrophysics Data System (ADS)

    Georges, Marc P.; Thizy, Cédric; Languy, Fabian; Vandenrijt, Jean-François

    2016-08-01

    We review some full-field interferometric techniques which have been successfully applied in different applications related to the aerospace industry. The first part of the paper concerns the long-wave infrared (LWIR) digital holographic interferometry which allows the measurement large displacements that occur when space structures undergo large temperature excursions. A second part of the paper concerns different developments in interferometric nondestructive testing (NDT) techniques intended to improve their usability in aerospace industrial environments. Among others, we discuss LWIR speckle interferometry for simultaneous deformation and temperature variation measurements and new post-processing techniques applied to shearography for an easier detection of flaws in composite structures.

  9. Optical Characterization of Window Materials for Aerospace Applications

    NASA Technical Reports Server (NTRS)

    Tedjojuwono, Ken K.; Clark, Natalie; Humphreys, William M., Jr.

    2013-01-01

    An optical metrology laboratory has been developed to characterize the optical properties of optical window materials to be used for aerospace applications. Several optical measurement systems have been selected and developed to measure spectral transmittance, haze, clarity, birefringence, striae, wavefront quality, and wedge. In addition to silica based glasses, several optical lightweight polymer materials and transparent ceramics have been investigated in the laboratory. The measurement systems and selected empirical results for non-silica materials are described. These measurements will be used to form the basis of acceptance criteria for selection of window materials for future aerospace vehicle and habitat designs.

  10. Optical characterization of window materials for aerospace applications

    NASA Astrophysics Data System (ADS)

    Tedjojuwono, Ken K.; Clark, Natalie; Humphreys, William M.

    2013-09-01

    An optical metrology laboratory has been developed to characterize the optical properties of optical window materials to be used for aerospace applications. Several optical measurement systems have been selected and developed to measure spectral transmittance, haze, clarity, birefringence, striae, wavefront quality, and wedge. In addition to silica based glasses, several optical lightweight polymer materials and transparent ceramics have been investigated in the laboratory. The measurement systems and selected empirical results for non-silica materials are described. These measurements will be used to form the basis of acceptance criteria for selection of window materials for future aerospace vehicle and habitat designs.

  11. Suitability of 2-Wire Ethernet Solutions for Aerospace Applications

    NASA Astrophysics Data System (ADS)

    Thain, A.; Le Sergent, F.; Marot, C.; Pasquier, B.

    2016-05-01

    The 100BASE-T1protocol is an Ethernet protocol allowing communications at 100 Mb/s on a single unshielded twisted pair cable. It was defined by the OPEN Alliance[1] working group that mainly comprised automobile manufacturers and suppliers, and therefore is specified for short cable lengths up to 15m. The technology originates from Broadcom who markets it as BroadR-Reach. It is of interest to the aerospace industry as a means of reducing weight, cost and installation time. In this paper we report on EMC tests performed to assess the suitability of the protocol for aerospace applications.

  12. Ceramic Integration Technologies for Energy and Aerospace Applications

    NASA Technical Reports Server (NTRS)

    Singh, Mrityunjay; Asthana, Ralph N.

    2007-01-01

    Robust and affordable integration technologies for advanced ceramics are required to improve the performance, reliability, efficiency, and durability of components, devices, and systems based on them in a wide variety of energy, aerospace, and environmental applications. Many thermochemical and thermomechanical factors including joint design, analysis, and optimization must be considered in integration of similar and dissimilar material systems.

  13. A standardized Cernox™ cryogenic temperature sensor for aerospace applications

    NASA Astrophysics Data System (ADS)

    Courts, Samuel Scott

    2014-11-01

    The success of any aerospace mission depends upon the reliability of the discrete components comprising the instrument. To this end, many test standards have been developed to define test protocols and methods for the parts used in these missions. To date, no recognized MIL-type standard exists for cryogenic temperature sensors that are used from room temperature to 20 K or below. The aerospace applications utilizing these sensors require the procuring entity to develop a specification which the sensor manufacturer uses to screen and qualify a single build lot for flight use. The individual applications often require only a small number of sensors with the end result being a relatively high cost and long delivery time. Over the past two decades, Lake Shore Cryotronics, Inc. has worked with many aerospace companies to supply Cernox™ cryogenic temperature sensors for numerous missions. The experience gained from this work has led to the development of a manufacturing and test protocol resulting in 'off-the-shelf' cryogenic temperature sensors that should meet the requirements for many aerospace applications. Sensors will be available at the base part level with the ability to configure the delivered part with regard to lead wire material, package adapter, lead wire extensions, and calibration as appropriate or necessary for the application. This work presents details of this manufacturing, inspection, and test protocol as well as performance characteristics of Cernox™ temperature sensors when inspected and tested to this protocol.

  14. Aerospace Applications of Magnetic Suspension Technology, part 2

    NASA Technical Reports Server (NTRS)

    Groom, Nelson J. (Editor); Britcher, Colin P. (Editor)

    1991-01-01

    In order to examine the state of technology of all areas of magnetic suspension with potential aerospace applications, and to review related recent developments in sensors and control approaches, superconducting technology, and design/implementation practices, a workshop was held at NASA-Langley. Areas of concern are pointing and isolation systems, microgravity and vibration isolation, bearing applications, wind tunnel model suspension systems, large gap magnetic suspension systems, controls, rotating machinery, science and applications of superconductivity, and sensors. Papers presented are included.

  15. Aerospace toxicology overview: aerial application and cabin air quality.

    PubMed

    Chaturvedi, Arvind K

    2011-01-01

    Aerospace toxicology is a rather recent development and is closely related to aerospace medicine. Aerospace toxicology can be defined as a field of study designed to address the adverse effects of medications, chemicals, and contaminants on humans who fly within or outside the atmosphere in aviation or on space flights. The environment extending above and beyond the surface of the Earth is referred to as aerospace. The term aviation is frequently used interchangeably with aerospace. The focus of the literature review performed to prepare this paper was on aerospace toxicology-related subject matters, aerial application and aircraft cabin air quality. Among the important topics addressed are the following: · Aerial applications of agricultural chemicals, pesticidal toxicity, and exposures to aerially applied mixtures of chemicals and their associated formulating solvents/surfactants The safety of aerially encountered chemicals and the bioanalytical methods used to monitor exposures to some of them · The presence of fumes and smoke, as well as other contaminants that may generally be present in aircraft/space vehicle cabin air · And importantly, the toxic effects of aerially encountered contaminants, with emphasis on the degradation products of oils, fluids, and lubricants used in aircraft, and finally · Analytical methods used for monitoring human exposure to CO and HCN are addressed in the review, as are the signs and symptoms associated with exposures to these combustion gases. Although many agricultural chemical monitoring studies have been published, few have dealt with the occurrence of such chemicals in aircraft cabin air. However, agricultural chemicals do appear in cabin air; indeed, attempts have been made to establish maximum allowable concentrations for several of the more potentially toxic ones that are found in aircraft cabin air. In this article, I emphasize the need for precautionary measures to be taken to minimize exposures to aerially

  16. Electron Beam Irradiated Intercalated CNT Yarns For Aerospace Applications

    NASA Technical Reports Server (NTRS)

    Waters, Deborah L.; Gaier, James R.; Williams, Tiffany S.; Lopez Calero, Johnny E.; Ramirez, Christopher; Meador, Michael A.

    2015-01-01

    Multi-walled CNT yarns have been experimentally and commercially created to yield lightweight, high conductivity fibers with good tensile properties for application as electrical wiring and multifunctional tendons. Multifunctional tendons are needed as the cable structures in tensegrity robots for use in planetary exploration. These lightweight robust tendons can provide mechanical strength for movement of the robot in addition to power distribution and data transmission. In aerospace vehicles, such as Orion, electrical wiring and harnessing mass can approach half of the avionics mass. Use of CNT yarns as electrical power and data cables could reduce mass of the wiring by thirty to seventy percent. These fibers have been intercalated with mixed halogens to increase their specific electrical conductivity to that near copper. This conductivity, combined with the superior strength and fatigue resistance makes it an attractive alternative to copper for wiring and multifunctional tendon applications. Electron beam irradiation has been shown to increase mechanical strength in pristine CNT fibers through increased cross-linking. Both pristine and intercalated CNT yarns have been irradiated using a 5-megavolt electron beam for various durations and the conductivities and tensile properties will be discussed. Structural information obtained using a field emission scanning electron microscope, energy dispersive X-ray spectroscopy (EDS), and Raman spectroscopy will correlate microstructural details with bulk properties.

  17. Aerospace Sensor Systems: From Sensor Development To Vehicle Application

    NASA Technical Reports Server (NTRS)

    Hunter, Gary W.

    2008-01-01

    This paper presents an overview of years of sensor system development and application for aerospace systems. The emphasis of this work is on developing advanced capabilities for measurement and control of aeropropulsion and crew vehicle systems as well as monitoring the safety of those systems. Specific areas of work include chemical species sensors, thin film thermocouples and strain gages, heat flux gages, fuel gages, SiC based electronic devices and sensors, space qualified electronics, and MicroElectroMechanical Systems (MEMS) as well as integrated and multifunctional sensor systems. Each sensor type has its own technical challenges related to integration and reliability in a given application. The general approach has been to develop base sensor technology using microfabrication techniques, integrate sensors with "smart" hardware and software, and demonstrate those systems in a range of aerospace applications. Descriptions of the sensor elements, their integration into sensors systems, and examples of sensor system applications will be discussed. Finally, suggestions related to the future of sensor technology will be given. It is concluded that smart micro/nano sensor technology can revolutionize aerospace applications, but significant challenges exist in maturing the technology and demonstrating its value in real-life applications.

  18. Lubricative coatings of copper oxide for aerospace applications

    NASA Astrophysics Data System (ADS)

    Goto, Masahiro; Kasahara, Akira; Oishi, Tetsuo; Konishi, Youko; Tosa, Masahiro

    2003-08-01

    Lubricative coatings of copper oxide on a stainless-steel substrate were synthesized by a rf magnetron sputter deposition method with a different gas ratio of oxygen and argon in sputter plasma. The crystal structure of the coatings was analyzed with x-ray diffraction spectroscopy. The friction force of the coating films in atmospheric pressure and in an ultrahigh vacuum (UHV) was evaluated by a vacuum pin-on-disk tribometer with different ball probes. Friction coefficients (μ) as low as 0.03 and 0.05 for a stainless-steel ball were achieved in atmospheric pressure and in an UHV, respectively. A value of μ=0.04 was also realized for a silicon nitride ball both in atmospheric pressure and in an UHV. Surface energy was analyzed by a contact angle measuring method which reveals that the behavior of the frictional properties correspond with that of the surface energy. Since the coatings consist of oxide, they will be applicable to a low-frictional coating with resistance to oxidation for aerospace applications in a low Earth orbit environment.

  19. Acceptance Criteria for Aerospace Structural Adhesives.

    DTIC Science & Technology

    ADHESIVES, *AIRFRAMES, PRIMERS, STRUCTURAL ENGINEERING, CHEMICAL COMPOSITION, MECHANICAL PROPERTIES, INDUSTRIAL PRODUCTION , DATA ACQUISITION , PARTICLE SIZE, ACCEPTANCE TESTS, ELASTOMERS, BONDING, QUALITY CONTROL, .

  20. Microfabricated Chemical Gas Sensors and Sensor Arrays for Aerospace Applications

    NASA Technical Reports Server (NTRS)

    Hunter, Gary W.

    2005-01-01

    Aerospace applications require the development of chemical sensors with capabilities beyond those of commercially available sensors. In particular, factors such as minimal sensor size, weight, and power consumption are particularly important. Development areas which have potential aerospace applications include launch vehicle leak detection, engine health monitoring, and fire detection. Sensor development for these applications is based on progress in three types of technology: 1) Micromachining and microfabrication (Microsystem) technology to fabricate miniaturized sensors; 2) The use of nanocrystalline materials to develop sensors with improved stability combined with higher sensitivity; 3) The development of high temperature semiconductors, especially silicon carbide. This presentation discusses the needs of space applications as well as the point-contact sensor technology and sensor arrays being developed to address these needs. Sensors to measure hydrogen, hydrocarbons, nitrogen oxides (NO,), carbon monoxide, oxygen, and carbon dioxide are being developed as well as arrays for leak, fire, and emissions detection. Demonstrations of the technology will also be discussed. It is concluded that microfabricated sensor technology has significant potential for use in a range of aerospace applications.

  1. Implications of Pb-free microelectronics assembly in aerospace applications

    NASA Technical Reports Server (NTRS)

    Shapiro, A. A.; Bonner, J. K.; Ogunseitan, D.; Saphores, J. D.; Schoenung, J.

    2003-01-01

    The commercial microelectronics industry is rapidly moving to completely Pb-free assembly strategies within the next decade. This trend is being driven by existing and proposed legislation in Europe and in Japan. The microelectronics industry has become truly global, as indicated by major U .S. firms who already adopted Pb-free implementation programs. Among these forward-looking firms are AT&T, IBM, Motorola, HP and Intel to name a few.Following Moore's law, advances in microelectronics are happening very rapidly. In many cases, commercial industry is ahead of the aerospace sector in technology. Progress by commercial industry, along with cost, drives the use of Commercial Off-The-Shelf (COTS) parts for military and space applications. We can thus anticipate that the aerospace industry will, at some point, be forced to use Pb-free components and subsystems as part of their standard business practices. In this paper we attempt to provide a snapshot of the commercial industry trends and how they may impact electronics in the aerospace environment. In addition, we also look at different strategies for implementation. Finally we present data collected on a recent NASA project to focus on finding suitable alternatives to eutectic tin-lead solders and solder pastes. The world is moving toward implementation of environmentally friendly manufacturing techniques. The aerospace industry will be forced to deal with issues related with Pb free assembly, either by availability or legislation. This paper provides some insight into some of the tradeoffs that should be considered.

  2. Advanced Materials and Multifunctional Structures for Aerospace Vehicles

    DTIC Science & Technology

    2006-10-01

    through covalent integration of functional nanotubes ”, Advanced Functional Materials, 14(7) (2004) 643-648. 185 R.Z. Ma, J. Wu, B.Q. Wei, J. Liang, and...on Advanced Materials for Multi Functional Structures in Aerospace Vehicles. The advanced synthesis, processing and the characterization techniques...when more than one primary function is performed either simultaneously or sequentially in time. These systems are based on metallic, ceramic and

  3. Recent GRC Aerospace Technologies Applicable to Terrestrial Energy Systems

    NASA Technical Reports Server (NTRS)

    Kankam, David; Lyons, Valerie J.; Hoberecht, Mark A.; Tacina, Robert R.; Hepp, Aloysius F.

    2000-01-01

    This paper is an overview of a wide range of recent aerospace technologies under development at the NASA Glenn Research Center, in collaboration with other NASA centers, government agencies, industry and academia. The focused areas are space solar power, advanced power management and distribution systems, Stirling cycle conversion systems, fuel cells, advanced thin film photovoltaics and batteries, and combustion technologies. The aerospace-related objectives of the technologies are generation of space power, development of cost-effective and reliable, high performance power systems, cryogenic applications, energy storage, and reduction in gas-turbine emissions, with attendant clean jet engines. The terrestrial energy applications of the technologies include augmentation of bulk power in ground power distribution systems, and generation of residential, commercial and remote power, as well as promotion of pollution-free environment via reduction in combustion emissions.

  4. Wear Characteristics of Oleophobic Coatings in Aerospace Applications

    NASA Astrophysics Data System (ADS)

    Shams, Hamza; Basit, Kanza

    2016-05-01

    This paper investigates the wear characteristics of oleophobic coatings when applied over Inconel 718, which has widespread applications in the aerospace industry. Coatings once applied were selectively exposed to controlled uni-and then multi-directional stand storm conditions. Size and speed of sand particles colliding with the work surface were carefully moderated to simulate sand storm conditions. Study of friction was performed using Lateral Force Microscopy (LFM) coupled with standard optical microscopy. The analysis has been used to devise a coefficient of friction value and in turn suggest wear behavior of the coated surface including the time associated with exposure of the base substrate. The analysis after validation aims to suggest methods for safe usage of these coatings for aerospace applications.

  5. Wear Characteristics of Oleophobic Coatings in Aerospace Applications

    NASA Astrophysics Data System (ADS)

    Shams, Hamza; Siddiqui, Bilal A.; Saleem, Sajid

    This paper investigates the wear characteristics of oleophobic coatings when applied over Inconel 718, which has widespread applications in the aerospace industry. Coatings once applied were selectively exposed to controlled uni-and then multi-directional stand storm conditions. Size and speed of sand particles colliding with the work surface were carefully moderated to simulate sand storm conditions. Study of friction was performed using Lateral Force Microscopy (LFM) coupled with standard optical microscopy. The analysis has been used to devise a coefficient of friction value and in turn suggest wear behavior of the coated surface including the time associated with exposure of the base substrate. The analysis after validation aims to suggest methods for safe usage of these coatings for aerospace applications.

  6. Aerospace applications of high temperature superconductivity

    NASA Technical Reports Server (NTRS)

    Heinen, V. O.; Connolly, D. J.

    1991-01-01

    Space application of high temperature superconducting (HTS) materials may occur before most terrestrial applications because of the passive cooling possibilities in space and because of the economic feasibility of introducing an expensive new technology which has a significant system benefit in space. NASA Lewis Research Center has an ongoing program to develop space technology capitalizing on the potential benefit of HTS materials. The applications being pursued include space communications, power and propulsion systems, and magnetic bearings. In addition, NASA Lewis is pursuing materials research to improve the performance of HTS materials for space applications.

  7. The design and fabrication of microstrip omnidirectional array antennas for aerospace applications

    NASA Technical Reports Server (NTRS)

    Campbell, T. G.; Appleton, M. W.; Lusby, T. K.

    1976-01-01

    A microstrip antenna design concept was developed that will provide quasi-omnidirectional radiation pattern characteristics about cylindrical and conical aerospace structures. L-band and S-band antenna arrays were designed, fabricated, and, in some cases, flight tested for rocket, satellite, and aircraft drone applications. Each type of array design is discussed along with a thermal cover design that was required for the sounding rocket applications.

  8. Additive Manufacturing of Superalloys for Aerospace Applications (Preprint)

    DTIC Science & Technology

    2008-03-01

    minimum quality standards, for example, as defined in MIL-STD 2219 , Fusion Welding for Aerospace Applications, Class A. Typical features that one...properties at room temperature and elevated temperatures, creep stress rupture, and some low cycle fatigue . Selected typical results are shown for... fatigue test results for IN 718 using the EBWD process. Strain-controlled LCF at 1000oF, A=1.0, strain=0.4%. 3 Creep testing results for IN 718 using

  9. Hybrid Control Systems: Design and Analysis for Aerospace Applications

    DTIC Science & Technology

    2009-02-28

    COVERED (From - To) 15-02-2006 - 30-11-200! 4. TITLE AND SUBTITLE Hybrid control systems : Design and analysis for aerospace applications 5a...of this research was to contribute to the fundamental understanding of hybrid control systems and to explore the use of hybrid feedback in problems...of interest to the Air Force. We aimed to provide a solid, foundational understanding of hybrid systems that will enable the vast potential of hybrid

  10. Magnetic Gearing Versus Conventional Gearing in Actuators for Aerospace Applications

    NASA Technical Reports Server (NTRS)

    Puchhammer, Gregor

    2014-01-01

    Magnetic geared actuators (MGA) are designed to perform highly reliable, robust and precise motion on satellite platforms or aerospace vehicles. The design allows MGA to be used for various tasks in space applications. In contrast to conventional geared drives, the contact and lubrication free force transmitting elements lead to a considerable lifetime and range extension of drive systems. This paper describes the fundamentals of magnetic wobbling gears (MWG) and the deduced inherent characteristics, and compares conventional and magnetic gearing.

  11. Finite element analysis of composites materials for aerospace applications

    NASA Astrophysics Data System (ADS)

    Nurhaniza, M.; Ariffin, M. K. A.; Ali, Aidy; Mustapha, F.; Noraini, A. W.

    2010-05-01

    Composites materials are intended to be used more extensively as an alternative of aluminum structure in aircraft and aerospace applications. This is due to their attractive properties as high strength-to-weight ratio and stiffness-to-weight ratio. Besides that it clarifies the growing interest for composites materials due to advantages of lightweight, high strength, high stiffness, superior fatigue life, tremendous corrosion resistance and low cost manufacturing. In this study, a finite element analysis (FEA) of fiberglass unidirectional E-type was analyzed in the framework of ABAQUS finite element commercial software. The analysis was done to quantify the mechanical properties and response of unidirectional E-glass in term of tensile, compression and thermal responses. From the analysis, the maximum and minimum values of stress and strain for E-glass 21xK43 Gevetex and Silenka E-glass 1200tex were obtained and stress-strain curve is presented. The ultimate load of failure, elastic behavior, tensile strength and other properties for each laminated plates under tensile and thermal-stress are determined from stress-strain curves. The simulation will run twice for each material where the first simulation based on orientation angles of 45° for ply-1, -45° for ply-2 and 90° for ply-3 while the second simulation, the orientation angles is 0° for all plies. The simulation is successfully conducted and verified by experimental data.

  12. Engineering derivatives from biological systems for advanced aerospace applications

    NASA Technical Reports Server (NTRS)

    Winfield, Daniel L.; Hering, Dean H.; Cole, David

    1991-01-01

    The present study consisted of a literature survey, a survey of researchers, and a workshop on bionics. These tasks produced an extensive annotated bibliography of bionics research (282 citations), a directory of bionics researchers, and a workshop report on specific bionics research topics applicable to space technology. These deliverables are included as Appendix A, Appendix B, and Section 5.0, respectively. To provide organization to this highly interdisciplinary field and to serve as a guide for interested researchers, we have also prepared a taxonomy or classification of the various subelements of natural engineering systems. Finally, we have synthesized the results of the various components of this study into a discussion of the most promising opportunities for accelerated research, seeking solutions which apply engineering principles from natural systems to advanced aerospace problems. A discussion of opportunities within the areas of materials, structures, sensors, information processing, robotics, autonomous systems, life support systems, and aeronautics is given. Following the conclusions are six discipline summaries that highlight the potential benefits of research in these areas for NASA's space technology programs.

  13. Computational technology for high-temperature aerospace structures

    NASA Technical Reports Server (NTRS)

    Noor, A. K.; Card, M. F.

    1992-01-01

    The status and some recent developments of computational technology for high-temperature aerospace structures are summarized. Discussion focuses on a number of aspects including: goals of computational technology for high-temperature structures; computational material modeling; life prediction methodology; computational modeling of high-temperature composites; error estimation and adaptive improvement strategies; strategies for solution of fluid flow/thermal/structural problems; and probabilistic methods and stochastic modeling approaches, integrated analysis and design. Recent trends in high-performance computing environment are described and the research areas which have high potential for meeting future technological needs are identified.

  14. Aerospace Structural Materials Handbook Supplement GRCop-84

    NASA Technical Reports Server (NTRS)

    Ellis, David L.; Gray, Hugh R. (Technical Monitor); Nathel, Michael (Technical Monitor)

    2001-01-01

    GRCop-84 is a high strength-high conductivity copper-based alloy developed at NASA Glenn Research Center for combustion chamber liners of regeneratively cooled rocket engines. It also has promise for other high heat flux applications operating at temperatures up to 700 C (1292 F) and potentially higher. The alloy must be made by powder metallurgy techniques such as gas atomization. Slower cooling rates such as those experienced during casting do not develop a proper microstructure. Once made into powder, the alloy exhibits excellent processability using conventional consolidation and forming techniques, e.g., extrusion and rolling. GRCop-84 is strengthened by a combination of dispersion and precipitation strengthening by fine (50-500 nanometer (2-20 microinch)) Cr2Nb particles and Hall-Petch strengthening from a fine copper grain size. The presence of a high volume fraction of particles prevents grain boundary sliding at high temperatures and contributes to the alloy's overall good high temperature mechanical properties. Maximum thermal conductivity is obtained by using two alloying elements (Cr, Nb) with limited solubility in solid Cu that form a high temperature intermetallic compound with an even lower solid solubility. The resulting matrix of the alloy is nearly pure copper. The limited solubility also minimizes Cr2Nb particle coarsening at elevated temperatures and enhances microstructural and mechanical property stability. Further enhancement of the microstructural stability is obtained by using a high volume fraction (approx. 14 vol.%) of Cr2Nb particles that effectively pin grain growth.

  15. Biomechanics finds practical applications in aerospace research

    NASA Astrophysics Data System (ADS)

    Yanghe, X.

    1984-10-01

    Biomechanics is a branch of science which studies the mechanical properties of biological parts using the basic principles of mechanics and engineering. Formulas and quantitative calculations are used to analyze and understand physiological phenomena. Problems caused by weightlessness, coronary heart disease, blood circulation, use of medication, and application of biomechanics in aviation rescue are discussed.

  16. Fiber optic interferometric sensors for aerospace applications

    NASA Technical Reports Server (NTRS)

    Cho, Y. C.

    1994-01-01

    This paper addresses two fiber optic sensor development programs in the Photonics Laboratory, NASA Ames Research Center, one in progress and the other being initiated. The ongoing program involves development of advanced acoustic sensors for wind tunnel applications. The new undertaking involves development of a novel sensor technique for studies of aerodynamic transition from laminar to turbulent flow.

  17. Electrically conducting polymers for aerospace applications

    NASA Technical Reports Server (NTRS)

    Meador, Mary Ann B.; Gaier, James R.; Good, Brian S.; Sharp, G. R.; Meador, Michael A.

    1991-01-01

    Current research on electrically conducting polymers from 1974 to the present is reviewed focusing on the development of materials for aeronautic and space applications. Problems discussed include extended pi-systems, pyrolytic polymers, charge-transfer systems, conductive matrix resins for composite materials, and prospects for the use of conducting polymers in space photovoltaics.

  18. Structural health management of aerospace hotspots under fatigue loading

    NASA Astrophysics Data System (ADS)

    Soni, Sunilkumar

    Sustainability and life-cycle assessments of aerospace systems, such as aircraft structures and propulsion systems, represent growing challenges in engineering. Hence, there has been an increasing demand in using structural health monitoring (SHM) techniques for continuous monitoring of these systems in an effort to improve safety and reduce maintenance costs. The current research is part of an ongoing multidisciplinary effort to develop a robust SHM framework resulting in improved models for damage-state awareness and life prediction, and enhancing capability of future aircraft systems. Lug joints, a typical structural hotspot, were chosen as the test article for the current study. The thesis focuses on integrated SHM techniques for damage detection and characterization in lug joints. Piezoelectric wafer sensors (PZTs) are used to generate guided Lamb waves as they can be easily used for onboard applications. Sensor placement in certain regions of a structural component is not feasible due to the inaccessibility of the area to be monitored. Therefore, a virtual sensing concept is introduced to acquire sensor data from finite element (FE) models. A full three dimensional FE analysis of lug joints with piezoelectric transducers, accounting for piezoelectrical-mechanical coupling, was performed in Abaqus and the sensor signals were simulated. These modeled sensors are called virtual sensors. A combination of real data from PZTs and virtual sensing data from FE analysis is used to monitor and detect fatigue damage in aluminum lug joints. Experiments were conducted on lug joints under fatigue loads and sensor signals collected were used to validate the simulated sensor response. An optimal sensor placement methodology for lug joints is developed based on a detection theory framework to maximize the detection rate and minimize the false alarm rate. The placement technique is such that the sensor features can be directly correlated to damage. The technique accounts for a

  19. Nonlinear analyses of composite aerospace structures in sonic fatigue

    NASA Technical Reports Server (NTRS)

    Mei, Chuh

    1992-01-01

    The primary research effort of this project is the development of analytical methods for the prediction of nonlinear random response of composite aerospace structures subjected to combined acoustic and thermal loads. The progress, accomplishments, and future plans of three random response research topics are discussed, namely acoustics-structure interactions using boundary/finite element methods, nonlinear vibrations of beams and composite plates under harmonic and random excitations, and numerical simulation of the nonlinear response of composite plates under combined thermal and acoustic loading.

  20. Comparison and analysis of two modern methods in the structural health monitoring techniques in aerospace

    NASA Astrophysics Data System (ADS)

    Riahi, Mohammad; Ahmadi, Alireza

    2016-04-01

    Role of air transport in the development and expansion of world trade leading to economic growth of different countries is undeniable. Continuing the world's trade sustainability without expansion of aerospace is next to impossible. Based on enormous expenses for design, manufacturing and maintenance of different aerospace structures, correct and timely diagnosis of defects in those structures to provide for maximum safety has the highest importance. Amid all this, manufacturers of commercial and even military aircrafts are after production of less expensive, lighter, higher fuel economy and nonetheless, higher safety. As such, two events has prevailed in the aerospace industries: (1) Utilization of composites for the fuselage as well as other airplane parts, (2) using modern manufacturing methods. Arrival of two these points have created the need for upgrading of the present systems as well as innovating newer methods in diagnosing and detection of defects in aerospace structures. Despite applicability of nondestructive testing (NDT) methods in aerospace for decades, due to some limitations in the defect detection's certainty, particularly for composite material and complex geometries, shadow of doubt has fallen on maintaining complete confidence in using NDT. These days, two principal approach are ahead to tackle the above mentioned problems. First, approach for the short range is the creative and combinational mean to increase the reliability of NDT and for the long run, innovation of new methods on the basis of structural health monitoring (SHM) is in order. This has led to new philosophy in the maintenance area and in some instances; field of design has also been affected by it.

  1. Proceedings: Ejector Workshop for Aerospace Applications

    DTIC Science & Technology

    1982-06-01

    triggering of a light source and superposition of all the schlieren images on a single photographic film. By this means, the images of the coherent...structure associated with the trigger signal are reinforced and those from the random tur- bulence tend to cancel. This method was used in our experiments...the cir- tudes, three frequencies (20, 30, 40Hz) at three * cuit trigger level. The signals were then vali- downstream stations (20, 40, 60x/h). Both

  2. Electrospun Electroactive Polymers for Aerospace Applications

    NASA Technical Reports Server (NTRS)

    Pawlowski, Kristin J.; St.Clair, Tyler L.; McReynolds, Amber C.; Park, Cheol; Ounaies, Zoubeida; Siochi, Emilie J.; Harrison, Joycelyn S.

    2003-01-01

    Electrospun piezoelectric polymers are being developed for use as a component on lightweight wings for micro-air vehicles (MAV). The goal is to incorporate fibers with tailored properties to permit dynamic control and maneuverability during flight. In particular, electrospun fiber mats of two piezoelectric polymers were investigated to ascertain their potential for the MAV application. In the work reported here, the typical experimental set-up for electrospinning was modified to induce fiber orientation in the spun mats. The morphologies of the resulting fibers and fiber mats were evaluated for various experimental conditions, and a comparison between oriented and unoriented fiber mats was carried out.

  3. Domestic applications for aerospace waste and water management technologies

    NASA Technical Reports Server (NTRS)

    Disanto, F.; Murray, R. W.

    1972-01-01

    Some of the aerospace developments in solid waste disposal and water purification, which are applicable to specific domestic problems are explored. Also provided is an overview of the management techniques used in defining the need, in utilizing the available tools, and in synthesizing a solution. Specifically, several water recovery processes will be compared for domestic applicability. Examples are filtration, distillation, catalytic oxidation, reverse osmosis, and electrodialysis. Solid disposal methods will be discussed, including chemical treatment, drying, incineration, and wet oxidation. The latest developments in reducing household water requirements and some concepts for reusing water will be outlined.

  4. Applications of aerospace technology in biology and medicine

    NASA Technical Reports Server (NTRS)

    1975-01-01

    Results of the medically related activities of the NASA Application Team Program at the Research Triangle Institute are reported. A survey of more than 300 major medical device manufacturers has been initiated for the purpose of determining their interest and opinions in regard to participating in the NASA Technology Utilization Program. Design and construction has been commissioned of a permanent exhibit of NASA Biomedical Application Team accomplishments for the aerospace building of the North Carolina Museum of Life and Science at Durham, North Carolina. The team has also initiated an expansion of its activities into the Northeastern United States.

  5. Micro/Nanoscale Chemicalsensor Systems for Aerospace Applications

    NASA Technical Reports Server (NTRS)

    Hunter, Gary; Xu, Jennifer; Evans, Laura; Biaggi-Labiosa, Azlin; Ward, Benjamin; Rowe, Scott; Makel, Darby; Liu, Chung Chiun; Dutta, Prabir; Berger, Gordon; VanderWal, Randy

    2010-01-01

    The aerospace industry requires development of a range of chemical-sensor technologies for applications including emissions monitoring as well as fuel-leak and fire detection. Improvements in sensing technology are necessary to increase safety, reduce emissions, and increase performance. The overall aim is to develop intelligent-vehicle systems that can autonomously monitor their state and respond to environmental changes. A range of chemical sensors is under development to meet these needs, based in part on microfabrication technology which produces sensors of minimal size, weight, and power consumption. We have fabricated a range of sensor platforms, integrated them with hardware to form complete sensor systems, and demonstrated their applicability.

  6. Advancement of braiding/resin transfer molding from commercial to aerospace applications

    NASA Astrophysics Data System (ADS)

    Sharpless, Garrett C.

    1991-03-01

    The braiding process, which produces dry fiber preforms fabricated to net shape for subsequent molding, and its compatible marriage to the resin transfer molding (RTM) process is producing a wide variety of composite products for commercial, recreational, and aircraft/aerospace applications. The design and fabrication of net-shaped braided preforms is the first step in the manufacture of braided/RTM composite parts. In most cases, braiding is the process of choice because the desired preform shape is usually complex. The stability of a braided structure makes it ideal for use in a subsequent RTM operation. The problems and techniques involved in the braiding of various complex preforms are discussed. The RTM process is then examined, along with its compatibility and flexibility with the braiding process in manufacturing. Examples are then presented of structurally demanding applications for braided/RTM composites in the aircraft and aerospace industries.

  7. Titanium/beryllium laminates: Fabrication, mechanical properties, and potential aerospace applications

    NASA Technical Reports Server (NTRS)

    Chamis, C. C.; Lark, R. F.

    1978-01-01

    The investigation indicated that structural laminates can be made which have: a modulus of elasticity comparable to steel, fracture strength of comparable to the yield strength of titanium, density comparable to aluminum, impact resistance comparable to titanium, and little or no notch sensitivity. These laminates can have stiffness and weight advantages over other materials including advanced fiber composites, in some aerospace applications where buckling resistance, vibration frequencies, and weight considerations control the design.

  8. Nonlinear analyses of composite aerospace structures in sonic fatigue

    NASA Technical Reports Server (NTRS)

    Mei, Chuh

    1993-01-01

    This report summarizes the semiannual research progress, accomplishments, and future plans performed under the NASA Langley Research Center Grant No. NAG-1-1358. The primary research effort of this project is the development of analytical methods for the prediction of nonlinear random response of composite aerospace structures subjected to combined acoustic and thermal loads. The progress, accomplishments, and future plates on four sonic fatigue research topics are described. The sonic fatigue design and passive control of random response of shape memory alloy hybrid composites presented in section 4, which is suited especially for HSCT, is a new initiative.

  9. A fiber optic temperature sensor for aerospace applications

    NASA Astrophysics Data System (ADS)

    Jensen, Stephen C.; Tilstra, Shelle D.; Barnabo, Geoffrey A.; Thomas, David C.; Phillips, Richard W.

    1991-02-01

    A fiber-optic temperature sensor has been developed for aerospace applications on the basis of the time rate of decay (TRD) principle, with a view to an operational temperature range of -60 to 350 C. This TRD system has completed qualification testing and will then undergo flight tests. Attention is presently given to the design and performance of four low temperature sensors that are subelements of the larger sensor system; in order to convert analog signals into over/under temperature indications, simple comparators are implemented in software.

  10. A Survey of Power Electronics Applications in Aerospace Technologies

    NASA Technical Reports Server (NTRS)

    Kankam, M. David; Elbuluk, Malik E.

    2001-01-01

    The insertion of power electronics in aerospace technologies is becoming widespread. The application of semiconductor devices and electronic converters, as summarized in this paper, includes the International Space Station, satellite power system, and motor drives in 'more electric' technology applied to aircraft, starter/generators and reusable launch vehicles. Flywheels, servo systems embodying electromechanical actuation, and spacecraft on-board electric propulsion are discussed. Continued inroad by power electronics depends on resolving incompatibility of using variable frequency for 400 Hz-operated aircraft equipment. Dual-use electronic modules should reduce system development cost.

  11. Graphite fiber reinforced glass matrix composites for aerospace applications

    NASA Technical Reports Server (NTRS)

    Prewo, K. M.; Bacon, J. F.; Dicus, D. L.

    1979-01-01

    The graphite fiber reinforced glass matrix composite system is described. Although this composite is not yet a mature material, it possesses low density, attractive mechanical properties at elevated temperatures, and good environmental stability. Properties are reported for a borosilicate glass matrix unidirectionally reinforced with 60 volume percent HMS graphite fiber. The flexural strength and fatigue characteristics at room and elevated temperature, resistance to thermal cycling and continuous high temperature oxidation, and thermal expansion characteristics of the composite are reported. The properties of this new composite are compared to those of advanced resin and metal matrix composites showing that graphite fiber reinforced glass matrix composites are attractive for aerospace applications.

  12. Smart Sensor Systems for Aerospace Applications: From Sensor Development to Application Testing

    NASA Technical Reports Server (NTRS)

    Hunter, G. W.; Xu, J. C.; Dungan, L. K.; Ward, B. J.; Rowe, S.; Williams, J.; Makel, D. B.; Liu, C. C.; Chang, C. W.

    2008-01-01

    The application of Smart Sensor Systems for aerospace applications is a multidisciplinary process consisting of sensor element development, element integration into Smart Sensor hardware, and testing of the resulting sensor systems in application environments. This paper provides a cross-section of these activities for multiple aerospace applications illustrating the technology challenges involved. The development and application testing topics discussed are: 1) The broadening of sensitivity and operational range of silicon carbide (SiC) Schottky gas sensor elements; 2) Integration of fire detection sensor technology into a "Lick and Stick" Smart Sensor hardware platform for Crew Exploration Vehicle applications; 3) Extended testing for zirconia based oxygen sensors in the basic "Lick and Stick" platform for environmental monitoring applications. It is concluded that that both core sensor platform technology and a basic hardware platform can enhance the viability of implementing smart sensor systems in aerospace applications.

  13. Reliability issues of COTS MEMS for aerospace applications

    NASA Astrophysics Data System (ADS)

    Ramesham, Rajeshuni; Ghaffarian, Reza; Kim, Namsoo P.

    1999-08-01

    During the last decade, research and development of microelectromechanical systems (MEMS) has shown a significant promise for a variety of commercial applications including automobile and medical purposes. For example, accelerometers are widely used for air bag in automobile and pressure sensors for various industrial applications. Some of the MEMS devices have potential to become the commercial- off-the-shelf (COTS) components. While high reliability applications including aerospace require much more sophisticated technology development, they would achieve significant cost savings if they could utilize COTS components in their systems. This paper reviews the current status of MEMS packaging technology from COTS to specific application provides lessons learned, and finally, identifies a need for a systematic approach for this purpose.

  14. Hybrid planar lightwave circuits for defense and aerospace applications

    NASA Astrophysics Data System (ADS)

    Zhang, Hua; Bidnyk, Serge; Yang, Shiquan; Balakrishnan, Ashok; Pearson, Matt; O'Keefe, Sean

    2010-04-01

    We present innovations in Planar Lightwave Circuits (PLCs) that make them ideally suited for use in advanced defense and aerospace applications. We discuss PLCs that contain no micro-optic components, no moving parts, pose no spark or fire hazard, are extremely small and lightweight, and are capable of transporting and processing a range of optical signals with exceptionally high performance. This PLC platform is designed for on-chip integration of active components such as lasers and detectors, along with transimpedance amplifiers and other electronics. These active components are hybridly integrated with our silica-on-silicon PLCs using fully-automated robotics and image recognition technology. This PLC approach has been successfully applied to the design and fabrication of multi-channel transceivers for aerospace applications. The chips contain hybrid DFB lasers and high-efficiency detectors, each capable of running over 10 Gb/s, with mixed digital and analog traffic multiplexed to a single optical fiber. This highlyintegrated functionality is combined onto a silicon chip smaller than 4 x 10 mm, weighing < 5 grams. These chip-based transceivers have been measured to withstand harsh g-forces, including sinusoidal vibrations with amplitude of 20 g acceleration, followed by mechanical shock of 500 g acceleration. The components operate over a wide range of temperatures, with no device failures after extreme temperature cycling through a range of > 125 degC, and more than 2,000 hours operating at 95 degC ambient air temperature. We believe that these recent advancements in planar lightwave circuits are poised to revolutionize optical communications and interconnects in the aerospace and defense industries.

  15. NASA-UVA light aerospace alloy and structures technology program

    NASA Technical Reports Server (NTRS)

    Gangloff, Richard P.; Haviland, John K.; Herakovich, Carl T.; Pilkey, Walter D.; Pindera, Marek-Jerzy; Thornton, Earl A.; Stoner, Glenn E.; Swanson, Robert E.; Wawner, Franklin E., Jr.; Wert, John A.

    1989-01-01

    The report on progress achieved in accomplishing of the NASA-UVA Light Aerospace Alloy and Structures Technology Program is presented. The objective is to conduct interdisciplinary graduate student research on the performance of next generation, light weight aerospace alloys and associated thermal gradient structures in close collaboration with researchers. The efforts will produce basic understanding of material behavior, new monolithic and composite alloys, processing methods, solid and fluid mechanics analyses, measurement advances, and a pool of educated graduate students. The presented accomplishments include: research on corrosion fatigue of Al-Li-Cu alloy 2090; research on the strengthening effect of small In additions to Al-Li-Cu alloys; research on localized corrosion of Al-Li alloys; research on stress corrosion cracking of Al-Li-Cu alloys; research on fiber-matrix reaction studies (Ti-1100 and Ti-15-3 matrices containing SCS-6, SCS-9, and SCS-10 fibers); and research on methods for quantifying non-random particle distribution in materials that has led to generation of a set of computer programs that can detect and characterize clusters in particles.

  16. Aerospace Application of Fiber Optic Strain Measurement Technology in Cryogenic Environments

    NASA Astrophysics Data System (ADS)

    Mizutani, Tadahito; Takeda, Nobuo

    Strain and temperature measurement, especially in cryogenic environments, was studied using fiber Bragg grating (FBG) sensors for the purpose of the aerospace structural health monitoring. Although the relationship between the applied strain and the Bragg wavelength shift was the same as that at room temperature, the temperature-wavelength relationship became non-linear under cryogenic environment. In order to show the applicability of the sensor in aerospace applications, FBG strain and temperature sensors were embedded in a composite liquid hydrogen tank and measured in the cryogenic and pressurized environment. Encapsulated and small-size temperature sensors were used in this article and the temperature drift of the strain sensor was compensated by using the output of the temperature sensor. It was revealed throughout the experiment that the optical power loss could be critical in the case of existing large temperature difference. The practical solution for this issue was also discussed in this article.

  17. Finite element thermo-viscoplastic analysis of aerospace structures

    NASA Technical Reports Server (NTRS)

    Pandey, Ajay K.; Dechaumphai, Pramote; Thornton, Earl A.

    1990-01-01

    The time-dependent thermo-viscoplastic response of aerospace structures subjected to intense aerothermal loads is predicted using the finite-element method. The finite-element analysis uses the Bodner-Partom unified viscoplastic constitutive relations to determine rate-dependent nonlinear material behavior. The methodology is verified by comparison with experimental data and other numerical results for a uniaxially-loaded bar. The method is then used (1) to predict the structural response of a rectangular plate subjected to line heating along a centerline, and (2) to predict the thermal-structural response of a convectively-cooled engine cowl leading edge subjected to aerodynamic shock-shock interference heating. Compared to linear elastic analysis, the viscoplastic analysis results in lower peak stresses and regions of plastic deformations.

  18. Active sensors for health monitoring of aging aerospace structures

    SciTech Connect

    GIURGIUTIU,VICTOR; REDMOND,JAMES M.; ROACH,DENNIS P.; RACKOW,KIRK A.

    2000-03-08

    A project to develop non-intrusive active sensors that can be applied on existing aging aerospace structures for monitoring the onset and progress of structural damage (fatigue cracks and corrosion) is presented. The state of the art in active sensors structural health monitoring and damage detection is reviewed. Methods based on (a) elastic wave propagation and (b) electro-mechanical (NM) impedance technique are sighted and briefly discussed. The instrumentation of these specimens with piezoelectric active sensors is illustrated. The main detection strategies (E/M impedance for local area detection and wave propagation for wide area interrogation) are discussed. The signal processing and damage interpretation algorithms are tuned to the specific structural interrogation method used. In the high-frequency EIM impedance approach, pattern recognition methods are used to compare impedance signatures taken at various time intervals and to identify damage presence and progression from the change in these signatures. In the wave propagation approach, the acoustic-ultrasonic methods identifying additional reflection generated from the damage site and changes in transmission velocity and phase are used. Both approaches benefit from the use of artificial intelligence neural networks algorithms that can extract damage features based on a learning process. Design and fabrication of a set of structural specimens representative of aging aerospace structures is presented. Three built-up specimens, (pristine, with cracks, and with corrosion damage) are used. The specimen instrumentation with active sensors fabricated at the University of South Carolina is illustrated. Preliminary results obtained with the E/M impedance method on pristine and cracked specimens are presented.

  19. Active sensors for health monitoring of aging aerospace structures

    SciTech Connect

    GIURGIUTIU,VICTOR; REDMOND,JAMES M.; ROACH,DENNIS P.; RACKOW,KIRK A.

    2000-02-29

    A project to develop non-intrusive active sensors that can be applied on existing aging aerospace structures for monitoring the onset and progress of structural damage (fatigue cracks and corrosion) is presented. The state of the art in active sensors structural health monitoring and damage detection is reviewed. Methods based on (a) elastic wave propagation and (b) electro-mechanical (E/M) impedance technique are cited and briefly discussed. The instrumentation of these specimens with piezoelectric active sensors is illustrated. The main detection strategies (E/M impedance for local area detection and wave propagation for wide area interrogation) are discussed. The signal processing and damage interpretation algorithms are tuned to the specific structural interrogation method used. In the high-frequency E/M impedance approach, pattern recognition methods are used to compare impedance signatures taken at various time intervals and to identify damage presence and progression from the change in these signatures. In the wave propagation approach, the acousto-ultrasonic methods identifying additional reflection generated from the damage site and changes in transmission velocity and phase are used. Both approaches benefit from the use of artificial intelligence neural networks algorithms that can extract damage features based on a learning process. Design and fabrication of a set of structural specimens representative of aging aerospace structures is presented. Three built-up specimens (pristine, with cracks, and with corrosion damage) are used. The specimen instrumentation with active sensors fabricated at the University of South Carolina is illustrated. Preliminary results obtained with the E/M impedance method on pristine and cracked specimens are presented.

  20. An expert system for integrated structural analysis and design optimization for aerospace structures

    NASA Technical Reports Server (NTRS)

    1992-01-01

    The results of a research study on the development of an expert system for integrated structural analysis and design optimization is presented. An Object Representation Language (ORL) was developed first in conjunction with a rule-based system. This ORL/AI shell was then used to develop expert systems to provide assistance with a variety of structural analysis and design optimization tasks, in conjunction with procedural modules for finite element structural analysis and design optimization. The main goal of the research study was to provide expertise, judgment, and reasoning capabilities in the aerospace structural design process. This will allow engineers performing structural analysis and design, even without extensive experience in the field, to develop error-free, efficient and reliable structural designs very rapidly and cost-effectively. This would not only improve the productivity of design engineers and analysts, but also significantly reduce time to completion of structural design. An extensive literature survey in the field of structural analysis, design optimization, artificial intelligence, and database management systems and their application to the structural design process was first performed. A feasibility study was then performed, and the architecture and the conceptual design for the integrated 'intelligent' structural analysis and design optimization software was then developed. An Object Representation Language (ORL), in conjunction with a rule-based system, was then developed using C++. Such an approach would improve the expressiveness for knowledge representation (especially for structural analysis and design applications), provide ability to build very large and practical expert systems, and provide an efficient way for storing knowledge. Functional specifications for the expert systems were then developed. The ORL/AI shell was then used to develop a variety of modules of expert systems for a variety of modeling, finite element analysis, and

  1. Real-Time Impact Visualization Inspection of Aerospace Composite Structures with Distributed Sensors.

    PubMed

    Si, Liang; Baier, Horst

    2015-07-08

    For the future design of smart aerospace structures, the development and application of a reliable, real-time and automatic monitoring and diagnostic technique is essential. Thus, with distributed sensor networks, a real-time automatic structural health monitoring (SHM) technique is designed and investigated to monitor and predict the locations and force magnitudes of unforeseen foreign impacts on composite structures and to estimate in real time mode the structural state when impacts occur. The proposed smart impact visualization inspection (IVI) technique mainly consists of five functional modules, which are the signal data preprocessing (SDP), the forward model generator (FMG), the impact positioning calculator (IPC), the inverse model operator (IMO) and structural state estimator (SSE). With regard to the verification of the practicality of the proposed IVI technique, various structure configurations are considered, which are a normal CFRP panel and another CFRP panel with "orange peel" surfaces and a cutout hole. Additionally, since robustness against several background disturbances is also an essential criterion for practical engineering demands, investigations and experimental tests are carried out under random vibration interfering noise (RVIN) conditions. The accuracy of the predictions for unknown impact events on composite structures using the IVI technique is validated under various structure configurations and under changing environmental conditions. The evaluated errors all fall well within a satisfactory limit range. Furthermore, it is concluded that the IVI technique is applicable for impact monitoring, diagnosis and assessment of aerospace composite structures in complex practical engineering environments.

  2. Real-Time Impact Visualization Inspection of Aerospace Composite Structures with Distributed Sensors

    PubMed Central

    Si, Liang; Baier, Horst

    2015-01-01

    For the future design of smart aerospace structures, the development and application of a reliable, real-time and automatic monitoring and diagnostic technique is essential. Thus, with distributed sensor networks, a real-time automatic structural health monitoring (SHM) technique is designed and investigated to monitor and predict the locations and force magnitudes of unforeseen foreign impacts on composite structures and to estimate in real time mode the structural state when impacts occur. The proposed smart impact visualization inspection (IVI) technique mainly consists of five functional modules, which are the signal data preprocessing (SDP), the forward model generator (FMG), the impact positioning calculator (IPC), the inverse model operator (IMO) and structural state estimator (SSE). With regard to the verification of the practicality of the proposed IVI technique, various structure configurations are considered, which are a normal CFRP panel and another CFRP panel with “orange peel” surfaces and a cutout hole. Additionally, since robustness against several background disturbances is also an essential criterion for practical engineering demands, investigations and experimental tests are carried out under random vibration interfering noise (RVIN) conditions. The accuracy of the predictions for unknown impact events on composite structures using the IVI technique is validated under various structure configurations and under changing environmental conditions. The evaluated errors all fall well within a satisfactory limit range. Furthermore, it is concluded that the IVI technique is applicable for impact monitoring, diagnosis and assessment of aerospace composite structures in complex practical engineering environments. PMID:26184196

  3. Applications of aerospace technology in biology and medicine

    NASA Technical Reports Server (NTRS)

    Beall, H. C.; Beadles, R. L.; Brown, J. N., Jr.; Clingman, W. H.; Courtney, M. W.; Rouse, D. J.; Scearce, R. W.

    1979-01-01

    Medical products utilizing and incorporating aerospace technology were studied. A bipolar donor-recipient model for medical transfer is presented. The model is designed to: (1) identify medical problems and aerospace technology which constitute opportunities for successful medical products; (2) obtain early participation of industry in the transfer process; and (3) obtain acceptance by medical community of new medical products based on aerospace technology.

  4. Intercalated graphite fiber composites as EMI shields in aerospace structures

    NASA Technical Reports Server (NTRS)

    Gaier, James R.

    1990-01-01

    The requirements for electromagnetic interference (EMI) shielding in aerospace structures are complicated over that of ground structures by their weight limitations. As a result, the best EMI shielding materials must blend low density, high strength, and high elastic modulus with high shielding ability. In addition, fabrication considerations including penetrations and joints play a major role. The EMI shielding properties are calculated for shields formed from pristine and intercalated graphite fiber/epoxy composites and compared to preliminary experimental results and to shields made from aluminum. Calculations indicate that EMI shields could be fabricated from intercalated graphite composites which would have less than 12 percent of the mass of conventional aluminum shields, based on mechanical properties and shielding properties alone.

  5. Ground Operations Aerospace Language (GOAL). Volume 5: Application Studies

    NASA Technical Reports Server (NTRS)

    1973-01-01

    The Ground Operations Aerospace Language (GOAL) was designed to be used by test oriented personnel to write procedures which would be executed in a test environment. A series of discussions between NASA LV-CAP personnel and IBM resulted in some peripheral tasks which would aid in evaluating the applicability of the language in this environment, and provide enhancement for future applications. The results of these tasks are contained within this volume. The GOAL vocabulary provides a high degree of readability and retainability. To achieve these benefits, however, the procedure writer utilizes words and phrases of considerable length. Brief form study was undertaken to determine a means of relieving this burden. The study resulted in a version of GOAL which enables the writer to develop a dialect suitable to his needs and satisfy the syntax equations. The output of the compiler would continue to provide readability by printing out the standard GOAL language. This task is described.

  6. A Knowledge-Based System Developer for aerospace applications

    NASA Technical Reports Server (NTRS)

    Shi, George Z.; Wu, Kewei; Fensky, Connie S.; Lo, Ching F.

    1993-01-01

    A prototype Knowledge-Based System Developer (KBSD) has been developed for aerospace applications by utilizing artificial intelligence technology. The KBSD directly acquires knowledge from domain experts through a graphical interface then builds expert systems from that knowledge. This raises the state of the art of knowledge acquisition/expert system technology to a new level by lessening the need for skilled knowledge engineers. The feasibility, applicability , and efficiency of the proposed concept was established, making a continuation which would develop the prototype to a full-scale general-purpose knowledge-based system developer justifiable. The KBSD has great commercial potential. It will provide a marketable software shell which alleviates the need for knowledge engineers and increase productivity in the workplace. The KBSD will therefore make knowledge-based systems available to a large portion of industry.

  7. An overview of integrated flywheel technology for aerospace application

    NASA Technical Reports Server (NTRS)

    Keckler, C. R.; Groom, N. J.

    1985-01-01

    Space missions ranging from small scientific satellites to large manned spacecraft have, for many years, utilized systems of spinning flywheels to maintain vehicle attitude. These systems have included momentum and reaction wheels as well as control moment gyros. Extension of that technology to satisfy the additional tasks associated with energy storage has also been pursued. The combining of control and energy storage features into one system has been examined by NASA for space applications and demonstrated in the laboratory. The impact of technology advances in such areas as composite material rotors, magnetic suspensions, motor/generators, and electronics have prompted a re-evaluation of the viability of the flywheel storage system concept for aerospace applications. This paper summarizes the results of this re-examination and identifies shortfalls in the various technology areas.

  8. Studies in automatic speech recognition and its application in aerospace

    NASA Astrophysics Data System (ADS)

    Taylor, Michael Robinson

    Human communication is characterized in terms of the spectral and temporal dimensions of speech waveforms. Electronic speech recognition strategies based on Dynamic Time Warping and Markov Model algorithms are described and typical digit recognition error rates are tabulated. The application of Direct Voice Input (DVI) as an interface between man and machine is explored within the context of civil and military aerospace programmes. Sources of physical and emotional stress affecting speech production within military high performance aircraft are identified. Experimental results are reported which quantify fundamental frequency and coarse temporal dimensions of male speech as a function of the vibration, linear acceleration and noise levels typical of aerospace environments; preliminary indications of acoustic phonetic variability reported by other researchers are summarized. Connected whole-word pattern recognition error rates are presented for digits spoken under controlled Gz sinusoidal whole-body vibration. Correlations are made between significant increases in recognition error rate and resonance of the abdomen-thorax and head subsystems of the body. The phenomenon of vibrato style speech produced under low frequency whole-body Gz vibration is also examined. Interactive DVI system architectures and avionic data bus integration concepts are outlined together with design procedures for the efficient development of pilot-vehicle command and control protocols.

  9. Optical Fiber Strain Instrumentation for High Temperature Aerospace Structural Monitoring

    NASA Technical Reports Server (NTRS)

    Wang, A.

    2002-01-01

    The objective of the program is the development and laboratory demonstration of sensors based on silica optical fibers for measurement of high temperature strain for aerospace materials evaluations. A complete fiber strain sensor system based on white-light interferometry was designed and implemented. An experiment set-up was constructed to permit testing of strain measurement up to 850 C. The strain is created by bending an alumina cantilever beam to which is the fiber sensor is attached. The strain calibration is provided by the application of known beam deflections. To ensure the high temperature operation capability of the sensor, gold-coated single-mode fiber is used. Moreover, a new method of sensor surface attachment which permits accurate sensor gage length determination is also developed. Excellent results were obtained at temperatures up to 800-850 C.

  10. NASA technology applications team. Applications of aerospace technology

    NASA Technical Reports Server (NTRS)

    1991-01-01

    Discussed here are the activities of the Research Triangle Institute (RTI) Technology Applications Team for the period 1 October 1990 through 30 September 1991. Topics researched include automated data acquisition and analysis of highway pavement cracking, thermal insulation for refrigerators, the containment of paint removed from steel structures, improved technologies for Kuwait oil well control, sprayed zinc coatings for corrosion control of reinforcing steel in bridges, and the monitoring and life support of medically fragile children in the educational setting.

  11. Novel atmospheric extinction measurement techniques for aerospace laser system applications

    NASA Astrophysics Data System (ADS)

    Sabatini, Roberto; Richardson, Mark

    2013-01-01

    Novel techniques for laser beam atmospheric extinction measurements, suitable for manned and unmanned aerospace vehicle applications, are presented in this paper. Extinction measurements are essential to support the engineering development and the operational employment of a variety of aerospace electro-optical sensor systems, allowing calculation of the range performance attainable with such systems in current and likely future applications. Such applications include ranging, weaponry, Earth remote sensing and possible planetary exploration missions performed by satellites and unmanned flight vehicles. Unlike traditional LIDAR methods, the proposed techniques are based on measurements of the laser energy (intensity and spatial distribution) incident on target surfaces of known geometric and reflective characteristics, by means of infrared detectors and/or infrared cameras calibrated for radiance. Various laser sources can be employed with wavelengths from the visible to the far infrared portions of the spectrum, allowing for data correlation and extended sensitivity. Errors affecting measurements performed using the proposed methods are discussed in the paper and algorithms are proposed that allow a direct determination of the atmospheric transmittance and spatial characteristics of the laser spot. These algorithms take into account a variety of linear and non-linear propagation effects. Finally, results are presented relative to some experimental activities performed to validate the proposed techniques. Particularly, data are presented relative to both ground and flight trials performed with laser systems operating in the near infrared (NIR) at λ = 1064 nm and λ = 1550 nm. This includes ground tests performed with 10 Hz and 20 kHz PRF NIR laser systems in a large variety of atmospheric conditions, and flight trials performed with a 10 Hz airborne NIR laser system installed on a TORNADO aircraft, flying up to altitudes of 22,000 ft.

  12. Evaluation of Sc-Bearing Aluminum Alloy C557 for Aerospace Applications

    NASA Technical Reports Server (NTRS)

    Domack, Marcia S.; Dicus, Dennis L.

    2002-01-01

    The performance of the Al-Mg-Sc alloy C557 was evaluated to assess its potential for a broad range of aerospace applications, including airframe and launch vehicle structures. Of specific interest were mechanical properties at anticipated service temperatures and thermal stability of the alloy. Performance was compared with conventional airframe aluminum alloys and with other emerging aluminum alloys developed for specific service environments. Mechanical properties and metallurgical structure were evaluated for commercially rolled sheet in the as-received H116 condition and after thermal exposures at 107 C. Metallurgical analyses were performed to de.ne grain morphology and texture, strengthening precipitates, and to assess the effect of thermal exposure.

  13. Optimization of Aerospace Structure Subject to Damage Tolerance Criteria

    NASA Technical Reports Server (NTRS)

    Akgun, Mehmet A.

    1999-01-01

    The objective of this cooperative agreement was to seek computationally efficient ways to optimize aerospace structures subject to damage tolerance criteria. Optimization was to involve sizing as well as topology optimization. The work was done in collaboration with Steve Scotti, Chauncey Wu and Joanne Walsh at the NASA Langley Research Center. Computation of constraint sensitivity is normally the most time-consuming step of an optimization procedure. The cooperative work first focused on this issue and implemented the adjoint method of sensitivity computation in an optimization code (runstream) written in Engineering Analysis Language (EAL). The method was implemented both for bar and plate elements including buckling sensitivity for the latter. Lumping of constraints was investigated as a means to reduce the computational cost. Adjoint sensitivity computation was developed and implemented for lumped stress and buckling constraints. Cost of the direct method and the adjoint method was compared for various structures with and without lumping. The results were reported in two papers. It is desirable to optimize topology of an aerospace structure subject to a large number of damage scenarios so that a damage tolerant structure is obtained. Including damage scenarios in the design procedure is critical in order to avoid large mass penalties at later stages. A common method for topology optimization is that of compliance minimization which has not been used for damage tolerant design. In the present work, topology optimization is treated as a conventional problem aiming to minimize the weight subject to stress constraints. Multiple damage configurations (scenarios) are considered. Each configuration has its own structural stiffness matrix and, normally, requires factoring of the matrix and solution of the system of equations. Damage that is expected to be tolerated is local and represents a small change in the stiffness matrix compared to the baseline (undamaged

  14. A Conceptual Aerospace Vehicle Structural System Modeling, Analysis and Design Process

    NASA Technical Reports Server (NTRS)

    Mukhopadhyay, Vivek

    2007-01-01

    A process for aerospace structural concept analysis and design is presented, with examples of a blended-wing-body fuselage, a multi-bubble fuselage concept, a notional crew exploration vehicle, and a high altitude long endurance aircraft. Aerospace vehicle structures must withstand all anticipated mission loads, yet must be designed to have optimal structural weight with the required safety margins. For a viable systems study of advanced concepts, these conflicting requirements must be imposed and analyzed early in the conceptual design cycle, preferably with a high degree of fidelity. In this design process, integrated multidisciplinary analysis tools are used in a collaborative engineering environment. First, parametric solid and surface models including the internal structural layout are developed for detailed finite element analyses. Multiple design scenarios are generated for analyzing several structural configurations and material alternatives. The structural stress, deflection, strain, and margins of safety distributions are visualized and the design is improved. Over several design cycles, the refined vehicle parts and assembly models are generated. The accumulated design data is used for the structural mass comparison and concept ranking. The present application focus on the blended-wing-body vehicle structure and advanced composite material are also discussed.

  15. NASA-UVA light aerospace alloy and structures technology program (LA(sup 2)ST)

    NASA Technical Reports Server (NTRS)

    Gangloff, Richard P.; Haviland, John K.; Herakovich, Carl T.; Pilkey, Walter D.; Pindera, Marek-Jerzy; Scully, John R.; Starke, Edgar A., Jr.; Stoner, Glenn E.; Thornton, Earl A.; Wawner, Franklin E., Jr.

    1992-01-01

    The general objective of the Light Aerospace Alloy and Structures Technology (LA(sup 2)ST) Program is to conduct interdisciplinary graduate student research on the performance of next generation, light weight aerospace alloys, composites, and thermal gradient structures in collaboration with Langley researchers. Specific technical objectives are established for each research project. We aim to produce relevant data and basic understanding of material behavior and microstructure, new monolithic and composite alloys, advanced processing methods, new solid and fluid mechanics analyses, measurement advances, and critically, a pool of educated graduate students for aerospace technologies. Four research areas are being actively investigated, including: (1) Mechanical and Environmental Degradation Mechanisms in Advanced Light Metals and Composites; (2) Aerospace Materials Science; (3) Mechanics of Materials and Composites for Aerospace Structures; and (4) Thermal Gradient Structures.

  16. Evaluation of Li/CF(x)Cells For Aerospace Applications

    NASA Technical Reports Server (NTRS)

    Vaidyanathan, Hari; Rao, Gopalakrishna M.

    2007-01-01

    Panasonic commercialized LiICF(x) cell technology in the 1970's. This technology was a promising primary battery for Aerospace applications such as: Exploration missions, Launch vehicles, Tools and more. This technology offers Wide operation temperature range, Low self-discharge and High specific energy CF(x) cathode material has a theoretical specific energy of 2260 Wh/Kg. Specific energy however achieved as of now is only 10% of theoretical value unless used at a very low rate of C/1000. Research both at Government Labs and Industries is currently in progress to improve the performance. This viewgraph presentation describes the cells, and reviews the results of some of the research using tables and charts.

  17. Nondestructive Damage Evaluation in Ceramic Matrix Composites for Aerospace Applications

    PubMed Central

    Dassios, Konstantinos G.; Kordatos, Evangelos Z.; Aggelis, Dimitrios G.; Matikas, Theodore E.

    2013-01-01

    Infrared thermography (IRT) and acoustic emission (AE) are the two major nondestructive methodologies for evaluating damage in ceramic matrix composites (CMCs) for aerospace applications. The two techniques are applied herein to assess and monitor damage formation and evolution in a SiC-fiber reinforced CMC loaded under cyclic and fatigue loading. The paper explains how IRT and AE can be used for the assessment of the material's performance under fatigue. IRT and AE parameters are specifically used for the characterization of the complex damage mechanisms that occur during CMC fracture, and they enable the identification of the micromechanical processes that control material failure, mainly crack formation and propagation. Additionally, these nondestructive parameters help in early prediction of the residual life of the material and in establishing the fatigue limit of materials rapidly and accurately. PMID:23935428

  18. Nondestructive damage evaluation in ceramic matrix composites for aerospace applications.

    PubMed

    Dassios, Konstantinos G; Kordatos, Evangelos Z; Aggelis, Dimitrios G; Matikas, Theodore E

    2013-01-01

    Infrared thermography (IRT) and acoustic emission (AE) are the two major nondestructive methodologies for evaluating damage in ceramic matrix composites (CMCs) for aerospace applications. The two techniques are applied herein to assess and monitor damage formation and evolution in a SiC-fiber reinforced CMC loaded under cyclic and fatigue loading. The paper explains how IRT and AE can be used for the assessment of the material's performance under fatigue. IRT and AE parameters are specifically used for the characterization of the complex damage mechanisms that occur during CMC fracture, and they enable the identification of the micromechanical processes that control material failure, mainly crack formation and propagation. Additionally, these nondestructive parameters help in early prediction of the residual life of the material and in establishing the fatigue limit of materials rapidly and accurately.

  19. Bipolar Nickel-hydrogen Batteries for Aerospace Applications

    NASA Technical Reports Server (NTRS)

    Koehler, C. W.; Vanommering, G.; Puester, N. H.; Puglisi, V. J.

    1984-01-01

    A bipolar nickel-hydrogen battery which effectively addresses all key requirements for a spacecraft power system, including long-term reliability and low mass, is discussed. The design of this battery is discussed in the context of system requirements and nickel-hydrogen battery technology in general. To achieve the ultimate goal of an aerospace application of a bipolar Ni-H2 battery several objectives must be met in the design and development of the system. These objectives include: maximization of reliability and life; high specific energy and energy density; reasonable cost of manufacture, test, and integration; and ease in scaling for growth in power requirements. These basic objectives translate into a number of specific design requirements, which are discussed.

  20. NASA-UVA Light Aerospace Alloy and Structures Technology Program (LA2ST)

    NASA Technical Reports Server (NTRS)

    Scully, John R.; Shiflet, Gary J.; Stoner, Glenn E.; Wert, John A.

    1996-01-01

    The NASA-UVA Light Aerospace Alloy and Structures Technology (LA2ST) Program was initiated in 1986 and continues with a high level of activity. The objective of the LA2ST Program is to conduct interdisciplinary graduate student research on the performance of next generation, light-weight aerospace alloys, composites and thermal gradient structures in collaboration with NASA-Langley researchers. Specific technical objectives are presented for each research project. We generally aim to produce relevant data and basic understanding of material mechanical response, environmental/corrosion behavior, and microstructure; new monolithic and composite alloys; advanced processing methods; new solid and fluid mechanics analyses; measurement and modeling advances; and a pool of educated graduate students for aerospace technologies. Three research areas are being actively investigated, including: (1) Mechanical and environmental degradation mechanisms in advanced light metals, (2) Aerospace materials science, and (3) Mechanics of materials for light aerospace structures.

  1. Closed form solutions of constrained trajectories - Application in optimal ascent of aerospace plane

    NASA Technical Reports Server (NTRS)

    Lu, Ping; Samsundar, John

    1992-01-01

    The present consideration of the flight trajectory of hypersonic aerospace vehicles subject to a class of path constraints notes the constrained dynamics to constitute a natural two-timescale system, so that problems of trajectory optimization and guidance can be dramatically simplified by means of the asymptotic analytical solutions thus obtained. An illustrative application in ascent trajectory optimization for an aerospace vehicle is presented.

  2. Leak Detection and Location Technology Assessment for Aerospace Applications

    NASA Technical Reports Server (NTRS)

    Wilson, William C.; Coffey, Neil C.; Madaras, Eric I.

    2008-01-01

    Micro Meteoroid and Orbital Debris (MMOD) and other impacts can cause leaks in the International Space Station and other aerospace vehicles. The early detection and location of leaks is paramount to astronaut safety. Therefore this document surveys the state of the art in leak detection and location technology for aerospace vehicles.

  3. Smart structures in engineering and technology: an aerospace and automotive perspective

    NASA Astrophysics Data System (ADS)

    Boller, Christian

    2003-03-01

    This paper gives an overview on what was expected to be achieved in smart structures and materials for aerospace and automotive applications about a decade ago and what so far could be achieved. Although initial goals turned out to be somewhat over-ambitious, achievements so far are worth to be discussed and pursued. Major ongoing activities being on the verge to be transferred into application are therefore summarized and referenced. A major lack in smart structures technology transfer has been identified being procedures on how to identify which technologies have the most likely chance to be transferred into application. A procedure for this successfully applied in market research and product development is therefore described and proposed here.

  4. Multi-application controls: Robust nonlinear multivariable aerospace controls applications

    NASA Technical Reports Server (NTRS)

    Enns, Dale F.; Bugajski, Daniel J.; Carter, John; Antoniewicz, Bob

    1994-01-01

    This viewgraph presentation describes the general methodology used to apply Honywell's Multi-Application Control (MACH) and the specific application to the F-18 High Angle-of-Attack Research Vehicle (HARV) including piloted simulation handling qualities evaluation. The general steps include insertion of modeling data for geometry and mass properties, aerodynamics, propulsion data and assumptions, requirements and specifications, e.g. definition of control variables, handling qualities, stability margins and statements for bandwidth, control power, priorities, position and rate limits. The specific steps include choice of independent variables for least squares fits to aerodynamic and propulsion data, modifications to the management of the controls with regard to integrator windup and actuation limiting and priorities, e.g. pitch priority over roll, and command limiting to prevent departures and/or undesirable inertial coupling or inability to recover to a stable trim condition. The HARV control problem is characterized by significant nonlinearities and multivariable interactions in the low speed, high angle-of-attack, high angular rate flight regime. Systematic approaches to the control of vehicle motions modeled with coupled nonlinear equations of motion have been developed. This paper will discuss the dynamic inversion approach which explicity accounts for nonlinearities in the control design. Multiple control effectors (including aerodynamic control surfaces and thrust vectoring control) and sensors are used to control the motions of the vehicles in several degrees-of-freedom. Several maneuvers will be used to illustrate performance of MACH in the high angle-of-attack flight regime. Analytical methods for assessing the robust performance of the multivariable control system in the presence of math modeling uncertainty, disturbances, and commands have reached a high level of maturity. The structured singular value (mu) frequency response methodology is presented

  5. Recent advances in AM OLED technologies for application to aerospace and military systems

    NASA Astrophysics Data System (ADS)

    Sarma, Kalluri R.; Roush, Jerry; Chanley, Charles

    2012-06-01

    While initial AM OLED products have been introduced in the market about a decade ago, truly successful commercialization of OLEDs has started only a couple of years ago, by Samsung Mobile Display (SMD), with small high performance displays for smart phone applications. This success by Samsung has catalyzed significant interest in AM OLED technology advancement and commercialization by other display manufacturers. Currently, significant manufacturing capacity for AM OLED displays is being established by the industry to serve the growing demand for these displays. The current development in the AM OLED industry are now focused on the development and commercialization of medium size (~10") AM OLED panels for Tablet PC applications and large size (~55") panels for TV applications. This significant progress in commercialization of AM OLED technology is enabled by major advances in various enabling technologies that include TFT backplanes, OLED materials and device structures and manufacturing know-how. In this paper we will discuss these recent advances, particularly as they relate to supporting high performance applications such as aerospace and military systems, and then discuss the results of the OLED testing for aerospace applications.

  6. Metals Technology for Aerospace Applications in 2020: Development of High Temperature Aluminum Alloys For Aerospace Applications

    NASA Technical Reports Server (NTRS)

    Dicus, Dennis (Technical Monitor); Starke, Edgar A., Jr.

    2003-01-01

    The role of trace additions on the nucleation and stability of the primary strengthening phase, omega, is of paramount importance for the enhancement of mechanical properties for moderate temperature application of Al-Cu-Mg-(Ag) alloys. In order to better understand the competition for solute, which governs the microstructural evolution of these alloys, a series of Al-Cu-Mg-Si quaternary alloys were prepared to investigate the role of trace Si additions on the nucleation of the omega phase. Si additions were found to quell omega nucleation in conjunction with the enhanced matrix precipitation of competing phases. These initial results indicate that it is necessary to overcome a critical Mg/Si ratio for omega precipitation, rather than a particular Si content.

  7. Fiber optic oxygen sensor using fluorescence quenching for aerospace application

    NASA Astrophysics Data System (ADS)

    Panahi, Allen

    2012-06-01

    In this paper we explore Fluorescence Technology as applied to the design and development of O2 sensors that can be used for aerospace application and discuss the various test and measurement techniques used to estimate the O2 gas concentration. Jet fuel comprised of heavier hydrocarbon components is much less volatile, than jet fuel having a flash point of approximately 37° C and JP-4 having a flash point of approximately -17° C. In contrast, straight-run gasoline has a flash point of approximately -40°C. The flash point is the minimum temperature where a liquid fuel can generate enough vapor to form a flammable mixture with air. If the temperature is below the flash point there isn't enough fuel evaporating to form a flammable fuel-air mixture. Since jet fuel and gasoline have similar flammable concentration limits, gasoline must produce much more vapor at a given temperature to have such a low flash point; hence gasoline is much more volatile than jet fuel. We compare the various intensity based approaches and contrast them with the frequency domain techniques that measure phase to extract fluorescent lifetimes. An innovate compact measurement system using the frequency heterodyning cross correlation technique that can be used for various applications is described in detail while the benefits are explored together with some test data collected. The various inerting fuel tank requirements are explained.

  8. Applications of aerospace technology in biology and medicine

    NASA Technical Reports Server (NTRS)

    Rouse, D. J.

    1983-01-01

    Utilization of NASA technology and its application to medicine is discussed. The introduction of new or improved commercially available medical products and incorporation of aerospace technology is outlined. A biopolar donor-recipient model of medical technology transfer is presented to provide a basis for the methodology. The methodology is designed to: (1) identify medical problems and NASA technology that, in combination, constitute opportunities for successful medical products; (2) obtain the early participation of industry in the transfer process; and (3) obtain acceptance by the medical community of new medical products based on NASA technology. Two commercial transfers were completed: the ocular screening device, a system for quick detection of vision problems in preschool children, and Porta-Fib III, a hospital monitoring unit. Two institutional transfers were completed: implant materials testing, the application of NASA fracture control technology to improve reliability of metallic prostheses, and incinerator monitoring, a quadrupole mass spectrometer to monitor combustion products of municipal incinerators. Mobility aids for the blind and ultrasound diagnosis of burn depth are also studied.

  9. Aerospace applications of sodium batteries using novel cathode materials

    NASA Technical Reports Server (NTRS)

    Ratnakumar, B. V.; Di Stefano, S.; Bankston, C. P.

    1989-01-01

    Preliminary fundamental investigations aimed at evaluating sodium metal chloride systems for future aerospace applications are described. Since the sodium metal chloride systems are relatively new, the approach has been to characterize their fundamental properties in order to understand their limitations. To this end, a series of fundamental electrochemical investigations have been carried out, the results of which are reported here. The metal chloride cathodes show high exchange current densities which corroborate their good reversibility in a battery application. The reduction mechanisms appear to be complex and involve multielectron transfer steps and intermediates. Such intermediates in the reaction mechanism have already been identified in the case of FeCl2. Similar mechanisms may be operative in the case of NiCl2. CuCl2, however, exhibits a second relaxation loop in the impedance plot at low frequencies and also a sloping discharge curve, unlike FeCl2 and NiCl2, which may indicate the existence of monovalent copper in the reduction mechanism.

  10. High efficiency digital cooler electronics for aerospace applications

    NASA Astrophysics Data System (ADS)

    Kirkconnell, C. S.; Luong, T. T.; Shaw, L. S.; Murphy, J. B.; Moody, E. A.; Lisiecki, A. L.; Ellis, M. J.

    2014-06-01

    Closed-cycle cryogenic refrigerators, or cryocoolers, are an enabling technology for a wide range of aerospace applications, mostly related to infrared (IR) sensors. While the industry focus has tended to be on the mechanical cryocooler thermo mechanical unit (TMU) alone, implementation on a platform necessarily consists of the combination of the TMU and a mating set of command and control electronics. For some applications the cryocooler electronics (CCE) are technologically simple and low cost relative to the TMU, but this is not always the case. The relative cost and complexity of the CCE for a space-borne application can easily exceed that of the TMU, primarily due to the technical constraints and cost impacts introduced by the typical space radiation hardness and reliability requirements. High end tactical IR sensor applications also challenge the state of the art in cryocooler electronics, such as those for which temperature setpoint and frequency must be adjustable, or those where an informative telemetry set must be supported, etc. Generally speaking for both space and tactical applications, it is often the CCE that limits the rated lifetime and reliability of the cryocooler system. A family of high end digital cryocooler electronics has been developed to address these needs. These electronics are readily scalable from 10W to 500W output capacity; experimental performance data for nominally 25W and 100W variants are presented. The combination of a FPGA-based controller and dual H-bridge motor drive architectures yields high efficiency (>92% typical) and precision temperature control (+/- 30 mK typical) for a wide range of Stirling-class mechanical cryocooler types and vendors. This paper focuses on recent testing with the AIM INFRAROT-MODULE GmbH (AIM) SX030 and AIM SF100 cryocoolers.

  11. Advanced fusion welding processes, solid state joining and a successful marriage. [production of aerospace structures

    NASA Technical Reports Server (NTRS)

    Miller, F. R.

    1972-01-01

    Joining processes for aerospace systems combine fusion welding and solid state joining during production of metal structures. Detailed characteristics of electron beam welding, plasma arc welding, diffusion welding, inertia welding and weldbond processes are discussed.

  12. Applications of aerospace technology to petroleum extraction and reservoir engineering

    NASA Technical Reports Server (NTRS)

    Jaffe, L. D.; Back, L. H.; Berdahl, C. M.; Collins, E. E., Jr.; Gordon, P. G.; Houseman, J.; Humphrey, M. F.; Hsu, G. C.; Ham, J. D.; Marte, J. E.; Owen, W. A.

    1977-01-01

    Through contacts with the petroleum industry, the petroleum service industry, universities and government agencies, important petroleum extraction problems were identified. For each problem, areas of aerospace technology that might aid in its solution were also identified, where possible. Some of the problems were selected for further consideration. Work on these problems led to the formulation of specific concepts as candidate for development. Each concept is addressed to the solution of specific extraction problems and makes use of specific areas of aerospace technology.

  13. 75 FR 60721 - Aerospace Supplier Development Mission to China; Recruitment Reopened for Additional Applications

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-01

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF COMMERCE International Trade Administration Aerospace Supplier Development Mission to China; Recruitment Reopened for Additional Applications AGENCY: International Trade Administration, Department of Commerce. ACTION:...

  14. Current Trends on the Applicability of Ground Aerospace Materials Test Data to Space System Environments

    NASA Technical Reports Server (NTRS)

    Hirsch, David B.

    2010-01-01

    This slide presentation discusses the application of testing aerospace materials to the environment of space for flammability. Test environments include use of drop towers, and the parabolic flight to simulate the low gravity environment of space.

  15. SEPEC conference proceedings: Hypermedia and Information Reconstruction. Aerospace applications and research directions

    NASA Technical Reports Server (NTRS)

    1990-01-01

    Papers presented at the conference on hypermedia and information reconstruction are compiled. The following subject areas are covered: real-world hypermedia projects, aerospace applications, and future directions in hypermedia research and development.

  16. An overview of SAFENET and its implications for aerospace applications

    NASA Technical Reports Server (NTRS)

    Collins, George C.; Bown, Rodney L.

    1991-01-01

    The survivable, adaptable fiber optic embeddable network (SAFENET) is a draft standard for local area networking (LAN) developed by the Navy which, when adopted, will become a military standard. The standard is being developed for procurement specifications of computer resources to be used on ships and aircraft and has some of the real-time concerns that network standards for space vehicles have. Architecture and survivability are considered. It is noted that the token-ring LAN must implement the IEEE 802.5 recommended practice for dual ring reconfiguration, which is currently being reviewed for inclusion into the IEEE standard. A trunk coupling unit is used at each station to isolate a station from the ring in case of failure. Up to five stations can be bypassed in this fashion. Communication architecture has an OSI profile but differs from the standard concept of the seven layers by allowing alternate suits and breaking the layers into three groupings of services to allow for physical interfacing. It also provides several paths, even if only one profile is used. Management and synchronization protocols are discussed and security issues are addressed. Implications for aerospace applications are considered and it is projected that interoperability with the Navy and other U.S. Government systems may require SAFENET specifications for NASA systems.

  17. High efficiency pulse tube cryocoolers for aerospace applications

    NASA Astrophysics Data System (ADS)

    Dang, Haizheng

    2014-01-01

    This paper reviews the recent advances in Stirling-type pulse tube cryocoolers for aerospace applications in the author's group. Due to the special environment featuring the limited power supply and adverse rejection condition, high cooler efficiencies are emphasized and thus the approaches to realize them are stressed. The cold fingers involve three geometries, and designs and optimizations on key dimensional parameters of coaxial and in-line ones for given compressors are discussed and compared. The high performance moving-coil linear compressors are studied, and the optimizations on linear motor and flexure springs are briefly reviewed as examples of studies on the key compressor technologies. The mature single-stage coolers cover 25-200 K with the capacities varying from milliwatt levels to over 30 W, and the high efficiencies at typical temperatures such as 40 K, 60 K, 80 K and 95 K are presented. The two-stage arrangement is becoming another trend to achieve cooling below 25 K and also to simultaneously provide cooling powers at both stages. Some typical development programs are introduced and a brief overview of the data package is updated.

  18. Fundamental Mechanisms, Predictive Modeling, and Novel Aerospace Applications of Plasma Assisted Combustion

    DTIC Science & Technology

    2011-11-01

    Fundamental Mechanisms, Predictive Modeling, and Novel Aerospace Applications of Plasma Assisted Combustion Yiguang Ju AFOSR MURI Review Meeting...SUBTITLE Fundamental Mechanisms, Predictive Modeling, and Novel Aerospace Applications of Plasma Assisted Combustion 5a. CONTRACT NUMBER 5b. GRANT...stabilization • Combustion completion F135 engine: (F35, 2011) Mach 6-8 Ignition instability Plasma assisted combustion Plasma Ions/electrons Excited species

  19. Development and Application of Microfabricated Chemical Gas Sensors For Aerospace Applications

    NASA Technical Reports Server (NTRS)

    Hunter, G. W.; Neudeck, P. G.; Fralick, G.; Thomas, V.; Liu, C. C.; Wu, Q. H.; Sawayda, M. S.; Jin, A.; Hammond, J.; Makel, D.; Hall, G.

    1990-01-01

    Aerospace applications require the development of chemical sensors with capabilities beyond those of commercially available sensors. In particular, factors such as minimal sensor size, weight, and power consumption are particularly important. Development areas which have potential aerospace applications include launch vehicle leak detection, engine health monitoring and control, and fire detection. Sensor development for these applications is based on progress in three types of technology: 1) Micromachining and microfabrication (Microsystem) technology to fabricate miniaturized sensors. 2) The use of nanocrystalline materials to develop sensors with improved stability combined with higher sensitivity. 3) The development of high temperature semiconductors, especially silicon carbide. Sensor development for each application involves its own challenges in the fields of materials science and fabrication technology. This paper discusses the needs of space applications and the point-contact sensor technology being developed to address these needs. Sensors to measure hydrogen, hydrocarbons, nitrogen oxides (Nox, carbon monoxide, oxygen, and carbon dioxide are being developed. A description is given of each sensor type and its present stage of development. Demonstration and application these sensor technologies will be described. The demonstrations range from use of a microsystem based hydrogen sensor on the Shuttle to engine demonstration of a nanocrystalline based sensor for NO, detection. It is concluded that microfabricated sensor technology has significant potential for use in a range of aerospace applications.

  20. Shape memory polymers and their composites in aerospace applications: a review

    NASA Astrophysics Data System (ADS)

    Liu, Yanju; Du, Haiyang; Liu, Liwu; Leng, Jinsong

    2014-02-01

    As a new class of smart materials, shape memory polymers and their composites (SMPs and SMPCs) can respond to specific external stimulus and remember the original shape. There are many types of stimulus methods to actuate the deformation of SMPs and SMPCs, of which the thermal- and electro-responsive components and structures are common. In this review, the general mechanism of SMPs and SMPCs are first introduced, the stimulus methods are then discussed to demonstrate the shape recovery effect, and finally, the applications of SMPs and SMPCs that are reinforced with fiber materials in aerospace are reviewed. SMPC hinges and booms are discussed in the part on components; the booms can be divided again into foldable SMPC truss booms, coilable SMPC truss booms and storable tubular extendible member (STEM) booms. In terms of SMPC structures, the solar array and deployable panel, reflector antenna and morphing wing are introduced in detail. Considering the factors of weight, recovery force and shock effect, SMPCs are expected to have great potential applications in aerospace.

  1. NASA-UVA light aerospace alloy and structures technology program (LA2ST)

    NASA Technical Reports Server (NTRS)

    Gangloff, Richard P.; Starke, Edger A., Jr.

    1996-01-01

    This progress report covers achievements made between January 1 and June 30, 1966 on the NASA-UVA Light Aerospace Alloy and Structures Technology (LA2ST) Program. The objective of the LA2ST Program is to conduct interdisciplinary graduate student research on the performance of next generation, light-weight aerospace alloys, composites and thermal gradient structures in collaboration with NASA-Langley researchers. Specific technical objectives are presented for each research project. . The accomplishments presented in this report are: (1) Mechanical and Environmental Degradation Mechanisms in Advanced Light Metals, (2) Aerospace Materials Science, and (3) Mechanics of Materials for Light Aerospace Structures. Collective accomplishments between January and June of 1996 include: 4 journal or proceedings publications, 1 NASA progress report, 4 presentations at national technical meetings, and 2 PhD dissertations published.

  2. Advances in processing of NiAl intermetallic alloys and composites for high temperature aerospace applications

    NASA Astrophysics Data System (ADS)

    Bochenek, Kamil; Basista, Michal

    2015-11-01

    Over the last few decades intermetallic compounds such as NiAl have been considered as potential high temperature structural materials for aerospace industry. A large number of investigations have been reported describing complex fabrication routes, introducing various reinforcing/alloying elements along with theoretical analyses. These research works were mainly focused on the overcoming of main disadvantage of nickel aluminides that still restricts their application range, i.e. brittleness at room temperature. In this paper we present an overview of research on NiAl processing and indicate methods that are promising in solving the low fracture toughness issue at room temperature. Other material properties relevant for high temperature applications are also addressed. The analysis is primarily done from the perspective of NiAl application in aero engines in temperature regimes from room up to the operating temperature (over 1150 °C) of turbine blades.

  3. ENSAERO - A multidisciplinary program for fluid/structural interaction studies of aerospace vehicles

    NASA Technical Reports Server (NTRS)

    Guruswamy, G. P.

    1990-01-01

    A computational procedure is developed that uses a moving zonal grid concept to model complex flexible aerospace vehicles. The Euler/Navier-Stokes equations are used to model the flow, and computations are made using efficient methods based on both central and upwind schemes. The structure is represented by a finite element method which can model general aerospace vehicles. Provisions are made to accommodate other disciplines such as controls and thermal loads. The code is capable of computing unsteady flows on flexible wings with vortical flows. Adaptation of this procedure for parallel processing and validation for complete aerospace configurations is in progress.

  4. Calibration of fiber Bragg gratings for optical sensing (FIBOS) for an aerospace application

    NASA Astrophysics Data System (ADS)

    Heredero, R. L.; Frovel, M.; Laguna, H.; Belenguer-Dávila, T.

    2009-03-01

    Fiber Bragg grating Sensors, FBGs, have been widely used as optical sensors for structural health monitoring of different materials. They can be embedded in composite structures or attached on their surface to monitor the entire life cycle of the material or to measure different physical parameters. FIBOS contains two FBGs and will be used to measure temperature and strain during the aerospace mission OPTOS. OPTOS is a picosatellite, designed and manufactured by the Spanish Institute for Aerospace Technology, INTA that will be launched during the summer 2009. The main goal of the mission is to demonstrate the possibility of using some novel technologies for space applications inside a miniaturized space and with big restrictions in terms of mass and power consumption. The paper describes the different units that constitute the FIBOS payload: one tunable laser, two FBGs mounted onto one steel mechanical structure to monitor independently temperature and strain and the processing unit that include all the electronics to control and connect the payload with the DOT of the satellite. Calibration measurements at different temperatures inside a thermalvacuum chamber as well as FIBOS operation during the mission are also presented.

  5. The prospects for European aerospace transporters. III - Applications of aerospace transporters. IV - Historical and political considerations

    NASA Astrophysics Data System (ADS)

    Collins, P. Q.; Ashford, D. M.

    1989-03-01

    A small, near-term-developed aerospace transporter would be useful for launching small satellites, servicing satellites in orbit, and supplying space stations, as well as furnishing a technology-development base for subsequent, larger vehicles. These larger vehicles have a potential cost/flight that is estimated to be of the order of 1000 times lower than that of the NASA Space Shuttle, at traffic levels typical of their use in tourism. An additional part of this work notes that the evolution of space transportation to date has been driven by considerations of defense policy and international prestige, with little priority given to the launch cost reductions that would be of paramount importance to passenger-carrying commercial ventures.

  6. NASA-UVA light aerospace alloy and structures technology program (LA2ST)

    NASA Technical Reports Server (NTRS)

    Gangloff, Richard P.

    1992-01-01

    The NASA-UVa Light Aerospace Alloy and Structure Technology (LAST) Program continues to maintain a high level of activity, with projects being conducted by graduate students and faculty advisors in the Departments of Materials Science and Engineering, Civil Engineering and Applied Mechanics, and Mechanical and Aerospace Engineering at the University of Virginia. This work is funded by the NASA-Langley Research Center under Grant NAG-1-745. Here, we report on progress achieved between January 1 and June 30, 1992. The objectives of the LA2ST Program is to conduct interdisciplinary graduate student research on the performance of the next generation, light weight aerospace alloys, composites and thermal gradient structures in collaboration with Langley researchers. Technical objectives are established for each research project. We aim to produce relevant data and basic understanding of material mechanical response, corrosion behavior, and microstructure; new monolithic and composite alloys; advanced processing methods; new solid and fluid mechanics analyses; measurement advances; and critically, a pool of educated graduate students for aerospace technologies. The accomplishments presented in this report cover topics including: (1) Mechanical and Environmental Degradation Mechanisms in Advance Light Metals and Composites; (2) Aerospace Materials Science; (3) Mechanics of Materials and Composites for Aerospace Structures; and (4) Thermal Gradient Structures.

  7. Electronic Components for use in Extreme Temperature Aerospace Applications

    NASA Technical Reports Server (NTRS)

    Patterson, Richard L.; Hammoud, Ahmad; Elbuluk, Malik

    2008-01-01

    Electrical power management and control systems designed for use in planetary exploration missions and deep space probes require electronics that are capable of efficient and reliable operation under extreme temperature conditions. Space-based infra-red satellites, all-electric ships, jet engines, electromagnetic launchers, magnetic levitation transport systems, and power facilities are also typical examples where the electronics are expected to be exposed to harsh temperatures and to operate under severe thermal swings. Most commercial-off-the-shelf (COTS) devices are not designed to function under such extreme conditions and, therefore, new parts must be developed or the conventional devices need to be modified. For example, spacecraft operating in the cold environment of deep space carry a large number of radioisotope heating units in order to maintain the surrounding temperature of the on-board electronics at approximately 20 C. At the other end, built-in radiators and coolers render the operation of electronics possible under hot conditions. These thermal measures lead to design complexity, affect development costs, and increase size and weight. Electronics capable of operation at extreme temperatures, thus, will not only tolerate the hostile operational environment, but also make the overall system efficient, more reliable, and less expensive. The Extreme Temperature Electronics Program at the NASA Glenn Research Center focuses on research and development of electronics suitable for applications in the aerospace environment and deep space exploration missions. Research is being conducted on devices, including COTS parts, for potential use under extreme temperatures. These components include semiconductor switching devices, passive devices, DC/DC converters, operational amplifiers, and oscillators. An overview of the program will be presented along with some experimental findings.

  8. Research Developments in Nondestructive Evaluation and Structural Health Monitoring for the Sustainment of Composite Aerospace Structures at NASA

    NASA Technical Reports Server (NTRS)

    Cramer, K. Elliott

    2016-01-01

    The use of composite materials continues to increase in the aerospace community due to the potential benefits of reduced weight, increased strength, and manufacturability. Ongoing work at NASA involves the use of the large-scale composite structures for spacecraft (payload shrouds, cryotanks, crew modules, etc). NASA is also working to enable both the use and sustainment of composites in commercial aircraft structures. One key to the sustainment of these large composite structures is the rapid, in-situ characterization of a wide range of potential defects that may occur during the vehicle's life. Additionally, in many applications it is necessary to monitor changes in these materials over their lifetime. Quantitative characterization through Nondestructive Evaluation (NDE) of defects such as reduced bond strength, microcracking, and delamination damage due to impact, are of particular interest. This paper will present an overview of NASA's applications of NDE technologies being developed for the characterization and sustainment of advanced aerospace composites. The approaches presented include investigation of conventional, guided wave, and phase sensitive ultrasonic methods and infrared thermography techniques for NDE. Finally, the use of simulation tools for optimizing and validating these techniques will also be discussed.

  9. NASA technology applications team: Applications of aerospace technology

    NASA Technical Reports Server (NTRS)

    1993-01-01

    This report covers the activities of the Research Triangle Institute (RTI) Technology Applications Team for the period 1 October 1992 through 30 September 1993. The work reported herein was supported by the National Aeronautics and Space Administration (NASA), Contract No. NASW-4367. Highlights of the RTI Applications Team activities over the past year are presented in Section 1.0. The Team's progress in fulfilling the requirements of the contract is summarized in Section 2.0. In addition to our market-driven approach to applications project development, RTI has placed increased effort on activities to commercialize technologies developed at NASA Centers. These Technology Commercialization efforts are summarized in Section 3.0. New problem statements prepared by the Team in the reporting period are presented in Section 4.0. The Team's transfer activities for ongoing projects with the NASA Centers are presented in Section 5.0. Section 6.0 summarizes the status of four add-on tasks. Travel for the reporting period is described in Section 7.0. The RTI Team staff and consultants and their project responsibilities are listed in Appendix A. Appendix B includes Technology Opportunity Announcements and Spinoff! Sheets prepared by the Team while Appendix C contains a series of technology transfer articles prepared by the Team.

  10. NASA technology applications team: Applications of aerospace technology

    NASA Technical Reports Server (NTRS)

    1989-01-01

    Two critical aspects of the Applications Engineering Program were especially successful: commercializing products of Application Projects; and leveraging NASA funds for projects by developing cofunding from industry and other agencies. Results are presented in the following areas: the excimer laser was commercialized for clearing plaque in the arteries of patients with coronary artery disease; the ultrasound burn depth analysis technology is to be licensed and commercialized; a phased commercialization plan was submitted to NASA for the intracranial pressure monitor; the Flexible Agricultural Robotics Manipulator System (FARMS) is making progress in the development of sensors and a customized end effector for a roboticized greenhouse operation; a dual robot are controller was improved; a multisensor urodynamic pressure catherer was successful in clinical tests; commercial applications were examined for diamond like carbon coatings; further work was done on the multichannel flow cytometer; progress on the liquid airpack for fire fighters; a wind energy conversion device was tested in a low speed wind tunnel; and the Space Shuttle Thermal Protection System was reviewed.

  11. Toward smart aerospace structures: design of a piezoelectric sensor and its analog interface for flaw detection.

    PubMed

    Boukabache, Hamza; Escriba, Christophe; Fourniols, Jean-Yves

    2014-10-31

    Structural health monitoring using noninvasive methods is one of the major challenges that aerospace manufacturers face in this decade. Our work in this field focuses on the development and the system integration of millimetric piezoelectric sensors/ actuators to generate and measure specific guided waves. The aim of the application is to detect mechanical flaws on complex composite and alloy structures to quantify efficiently the global structures' reliability. The study begins by a physical and analytical analysis of a piezoelectric patch. To preserve the structure's integrity, the transducers are directly pasted onto the surface which leads to a critical issue concerning the interfacing layer. In order to improve the reliability and mitigate the influence of the interfacing layer, the global equations of piezoelectricity are coupled with a load transfer model. Thus we can determine precisely the shear strain developed on the surface of the structure. To exploit the generated signal, a high precision analog charge amplifier coupled to a double T notch filter were designed and scaled. Finally, a novel joined time-frequency analysis based on a wavelet decomposition algorithm is used to extract relevant structures signatures. Finally, this paper provides examples of application on aircraft structure specimens and the feasibility of the system is thus demonstrated.

  12. Toward Smart Aerospace Structures: Design of a Piezoelectric Sensor and Its Analog Interface for Flaw Detection

    PubMed Central

    Boukabache, Hamza; Escriba, Christophe; Fourniols, Jean-Yves

    2014-01-01

    Structural health monitoring using noninvasive methods is one of the major challenges that aerospace manufacturers face in this decade. Our work in this field focuses on the development and the system integration of millimetric piezoelectric sensors/ actuators to generate and measure specific guided waves. The aim of the application is to detect mechanical flaws on complex composite and alloy structures to quantify efficiently the global structures' reliability. The study begins by a physical and analytical analysis of a piezoelectric patch. To preserve the structure's integrity, the transducers are directly pasted onto the surface which leads to a critical issue concerning the interfacing layer. In order to improve the reliability and mitigate the influence of the interfacing layer, the global equations of piezoelectricity are coupled with a load transfer model. Thus we can determine precisely the shear strain developed on the surface of the structure. To exploit the generated signal, a high precision analog charge amplifier coupled to a double T notch filter were designed and scaled. Finally, a novel joined time-frequency analysis based on a wavelet decomposition algorithm is used to extract relevant structures signatures. Finally, this paper provides examples of application on aircraft structure specimens and the feasibility of the system is thus demonstrated. PMID:25365457

  13. NASA Technology Applications Team: Commercial applications of aerospace technology

    NASA Technical Reports Server (NTRS)

    1994-01-01

    The Research Triangle Institute (RTI) is pleased to report the results of NASA contract NASW-4367, 'Operation of a Technology Applications Team'. Through a period of significant change within NASA, the RTI Team has maintained its focus on helping NASA establish partnerships with U.S. industry for dual use development and technology commercialization. Our emphasis has been on outcomes, such as licenses, industry partnerships and commercialization of technologies that are important to NASA in its mission of contributing to the improved competitive position of U.S. industry. RTI's ongoing commitment to quality and customer responsiveness has driven our staff to continuously improve our technology transfer methodologies to meet NASA's requirements. For example, RTI has emphasized the following areas: (1) Methodology For Technology Assessment and Marketing: RTI has developed an implemented effective processes for assessing the commercial potential of NASA technologies. These processes resulted from an RTI study of best practices, hands-on experience, and extensive interaction with the NASA Field Centers to adapt to their specific needs; (2) Effective Marketing Strategies: RTI surveyed industry technology managers to determine effective marketing tools and strategies. The Technology Opportunity Announcement format and content were developed as a result of this industry input. For technologies with a dynamic visual impact, RTI has developed a stand-alone demonstration diskette that was successful in developing industry interest in licensing the technology; and (3) Responsiveness to NASA Requirements: RTI listened to our customer (NASA) and designed our processes to conform with the internal procedures and resources at each NASA Field Center and the direction provided by NASA's Agenda for Change. This report covers the activities of the Research Triangle Institute Technology Applications Team for the period 1 October 1993 through 31 December 1994.

  14. Advantage of resonant power conversion in aerospace applications

    NASA Technical Reports Server (NTRS)

    Hansen, I. G.

    1983-01-01

    An ultrasonic, sinusoidal aerospace power distribution system is shown to have many advantages over other candidate power systems. These advantages include light weight, ease of fault clearing, versatility in handling many loads including motors, and the capability of production within the limits of present technology. References are cited that demonstrate the state of resonant converter technology and support these conclusions.

  15. NASA Technology Applications Team: Commercial applications of aerospace technology

    NASA Technical Reports Server (NTRS)

    1994-01-01

    The Research Triangle Institute (RTI) Team has maintained its focus on helping NASA establish partnerships with U.S. industry for dual use development and technology commercialization. Our emphasis has been on outcomes, such as licenses, industry partnerships and commercialization of technologies, that are important to NASA in its mission of contributing to the improved competitive position of U.S. industry. The RTI Team has been successful in the development of NASA/industry partnerships and commercialization of NASA technologies. RTI ongoing commitment to quality and customer responsiveness has driven our staff to continuously improve our technology transfer methodologies to meet NASA's requirements. For example, RTI has emphasized the following areas: (1) Methodology For Technology Assessment and Marketing: RTI has developed and implemented effective processes for assessing the commercial potential of NASA technologies. These processes resulted from an RTI study of best practices, hands-on experience, and extensive interaction with the NASA Field Centers to adapt to their specific needs. (2) Effective Marketing Strategies: RTI surveyed industry technology managers to determine effective marketing tools and strategies. The Technology Opportunity Announcement format and content were developed as a result of this industry input. For technologies with a dynamic visual impact, RTI has developed a stand-alone demonstration diskette that was successful in developing industry interest in licensing the technology. And (3) Responsiveness to NASA Requirements: RTI listened to our customer (NASA) and designed our processes to conform with the internal procedures and resources at each NASA Field Center and the direction provided by NASA's Agenda for Change. This report covers the activities of the Research Triangle Institute Technology Applications Team for the period 1 October 1993 through 31 December 1994.

  16. Dynamic fiber Bragg gratings based health monitoring system of composite aerospace structures

    NASA Astrophysics Data System (ADS)

    Panopoulou, A.; Loutas, T.; Roulias, D.; Fransen, S.; Kostopoulos, V.

    2011-09-01

    The main purpose of the current work is to develop a new system for structural health monitoring of composite aerospace structures based on real-time dynamic measurements, in order to identify the structural state condition. Long-gauge Fibre Bragg Grating (FBG) optical sensors were used for monitoring the dynamic response of the composite structure. The algorithm that was developed for structural damage detection utilizes the collected dynamic response data, analyzes them in various ways and through an artificial neural network identifies the damage state and its location. Damage was simulated by slightly varying locally the mass of the structure (by adding a known mass) at different zones of the structure. Lumped masses in different locations upon the structure alter the eigen-frequencies in a way similar to actual damage. The structural dynamic behaviour has been numerically simulated and experimentally verified by means of modal testing on two different composite aerospace structures. Advanced digital signal processing techniques, e.g. the wavelet transform (WT), were used for the analysis of the dynamic response for feature extraction. WT's capability of separating the different frequency components in the time domain without loosing frequency information makes it a versatile tool for demanding signal processing applications. The use of WT is also suggested by the no-stationary nature of dynamic response signals and the opportunity of evaluating the temporal evolution of their frequency contents. Feature extraction is the first step of the procedure. The extracted features are effective indices of damage size and location. The classification step comprises of a feed-forward back propagation network, whose output determines the simulated damage location. Finally, dedicated training and validation activities were carried out by means of numerical simulations and experimental procedures. Experimental validation was performed initially on a flat stiffened panel

  17. Liquid-crystal variable retarders for aerospace polarimetry applications.

    PubMed

    Heredero, R L; Uribe-Patarroyo, N; Belenguer, T; Ramos, G; Sánchez, A; Reina, M; Pillet, V Martínez; Alvarez-Herrero, A

    2007-02-10

    We present the optical effects of different tests that simulate the aerospace environment on the liquid-crystal variable retarders (LCVRs) used in the Imaging Magnetograph eXperiment postfocal instrument of the SUNRISE payload within the NASA Long Duration Balloon program. Analysis of the influence of vacuum, temperature, vibration, and gamma and ultraviolet radiation is performed by measuring the effects of these tests on the optical retardance, the response time, the wavefront distortion, and the transmittance, including some in situ measurements. Outgassing measurements of the different parts of the LCVRs are also shown. From the results obtained it can be concluded that these optical devices are suitable and seem to be excellent candidates for aerospace platforms.

  18. Applications of aerospace technology in the public interest: Pollution measurement

    NASA Technical Reports Server (NTRS)

    Heins, C. F.; Johnson, F. D.

    1974-01-01

    This study of selected NASA contributions to the improvement of pollution measurement examines the pervasiveness and complexity of the economic, political, and social issues in the environmental field; provides a perspective on the relationship between the conduct of aerospace R and D and specific improvements in on site air pollution monitoring equipment now in use; describes the basic relationship between the development of satellite-based monitoring systems and their influence on long-term progress in improving environmental quality; and comments on how both instrumentation and satellite remote sensing are contributing to an improved environment. Examples of specific gains that have been made in applying aerospace R and D to environmental problem-solving are included.

  19. Output Feedback M-MRAC Backstepping With Aerospace Applications

    NASA Technical Reports Server (NTRS)

    Stepanyan, Vahram; Krishnakumar, Kalmanje Sriniva

    2014-01-01

    The paper presents a certainty equivalence output feedback backstepping adaptive control design method for the systems of any relative degree with unmatched uncertainties without over-parametrization. It uses a fast prediction model to estimate the unknown parameters, which is independent of the control design. It is shown that the system's input and output tracking errors can be systematically decreased by the proper choice of the design parameters. The approach is applied to aerospace control problems and tested in numerical simulations.

  20. Fiber Optic Thermal Health Monitoring of Aerospace Structures and Materials

    NASA Technical Reports Server (NTRS)

    Wu, Meng-Chou; Winfree, William P.; Allison, Sidney G.

    2009-01-01

    A new technique is presented for thermographic detection of flaws in materials and structures by performing temperature measurements with fiber Bragg gratings. Individual optical fibers with multiple Bragg gratings employed as surface temperature sensors were bonded to the surfaces of structures with subsurface defects or thickness variations. Both during and following the application of a thermal heat flux to the surface, the individual Bragg grating sensors measured the temporal and spatial temperature variations. The investigated structures included a 10-ply composite specimen with subsurface delaminations of various sizes and depths. The data obtained from grating sensors were further analyzed with thermal modeling to reveal particular characteristics of the interested areas. These results were found to be consistent with those from conventional thermography techniques. Limitations of the technique were investigated using both experimental and numerical simulation techniques. Methods for performing in-situ structural health monitoring are discussed.

  1. Recent Advances In Optimization Of Aerospace Structures And Engines

    NASA Astrophysics Data System (ADS)

    Rao*, J. S.

    Optimization theories have been well advanced during the last few decades; however when it came to handle real life engineering structures it has been always time consuming and approximate when the structure geometry is highly complex. Design of Experiments has helped in understanding the influence of size and shape parameters on achieving a specified objective function with required constraints and a suitable analysis platform, but has its limitations in arriving at the final optimal solution. There are several commercial codes that addressed this need to handle large size structures subjected to dynamic loads. Most advanced tools in this category are Altair OptiStruct and Altair HyperStudy available in Altair HyperWorks suite. Application of these tools in achieving optimum solutions for linear advanced aircraft structures for minimization of weight are first explained. The application of these tools for globally elastic and locally plastic nonlinear structures to reduce local plastic strains and achieve higher life under dynamic loads will then be discussed.

  2. A Unified Model for Predicting the Open Hole Tensile and Compressive Strengths of Composite Laminates for Aerospace Applications

    NASA Technical Reports Server (NTRS)

    Davidson, Paul; Pineda, Evan J.; Heinrich, Christian; Waas, Anthony M.

    2013-01-01

    The open hole tensile and compressive strengths are important design parameters in qualifying fiber reinforced laminates for a wide variety of structural applications in the aerospace industry. In this paper, we present a unified model that can be used for predicting both these strengths (tensile and compressive) using the same set of coupon level, material property data. As a prelude to the unified computational model that follows, simplified approaches, referred to as "zeroth order", "first order", etc. with increasing levels of fidelity are first presented. The results and methods presented are practical and validated against experimental data. They serve as an introductory step in establishing a virtual building block, bottom-up approach to designing future airframe structures with composite materials. The results are useful for aerospace design engineers, particularly those that deal with airframe design.

  3. NASA-UVA Light Aerospace Alloy and Structures Technology Program (LA2ST)

    NASA Technical Reports Server (NTRS)

    Gangloff, Richard P.; Starke, Edgar A., Jr.; Kelly, Robert G.; Scully, John R.; Shiflet, Gary J.; Stoner, Glenn E.; Wert, John A.

    1997-01-01

    The NASA-UVA Light Aerospace Alloy and Structures Technology (LA2ST) Program was initiated in 1986 and continues with a high level of activity. Here, we report on progress achieved between July I and December 31, 1996. The objective of the LA2ST Program is to conduct interdisciplinary graduate student research on the performance of next generation, light-weight aerospace alloys, composites and thermal gradient structures in collaboration with NASA-Langley researchers. Specific technical objectives are presented for each research project. We generally aim to produce relevant data and basic understanding of material mechanical response, environmental/corrosion behavior, and microstructure; new monolithic and composite alloys; advanced processing methods; new solid and fluid mechanics analyses; measurement and modeling advances; and a pool of educated graduate students for aerospace technologies. The accomplishments presented in this report are summarized as follows. Three research areas are being actively investigated, including: (1) Mechanical and Environmental Degradation Mechanisms in Advanced Light Metals, (2) Aerospace Materials Science, and (3) Mechanics of Materials for Light Aerospace Structures.

  4. Modular photonic power and VCSEL-based data links for aerospace and military applications

    SciTech Connect

    Carson, R.F.

    1997-02-01

    If photonic data and power transfer links are constructed in a modular fashion, they can be easily adapted into various forms to meet a wide range of needs for aerospace and military applications. The performance specifications associated with these needs can vary widely according to application. Alignment tolerance needs also tend to vary greatly, as can requirements on power consumption. An example of a modular photonic data and/or power transfer link that can be applied to military and aerospace needs is presented. In this approach, a link is designed for low (<10 kb/s) data rates, ultra-low electrical power consumption, large alignment tolerance, and power transfer to provide complete electrical shielding in a remote module that might be found in a military or aerospace application.

  5. Photogrammetric Verification of Fiber Optic Shape Sensors on Flexible Aerospace Structures

    NASA Technical Reports Server (NTRS)

    Moore, Jason P.; Rogge, Matthew D.; Jones, Thomas W.

    2012-01-01

    Multi-core fiber (MCF) optic shape sensing offers the possibility of providing in-flight shape measurements of highly flexible aerospace structures and control surfaces for such purposes as gust load alleviation, flutter suppression, general flight control and structural health monitoring. Photogrammetric measurements of surface mounted MCF shape sensing cable can be used to quantify the MCF installation path and verify measurement methods.

  6. NASA-UVA Light Aerospace Alloy and Structures Technology Program (LA2ST)

    NASA Technical Reports Server (NTRS)

    Gangloff, Richard P.

    1991-01-01

    The general objective of the Light Aerospace Alloy and Structures Technology (LA2ST) Program is to conduct interdisciplinary graduate student research on the performance of next generation, light weight aerospace alloys, composites, and associated thermal gradient structures in close collaboration with Langley researchers. Specific technical objectives are established for each research project. Relevant data and basic understanding of material behavior and microstructure, new monolithic and composite alloys, advanced processing methods, new solid and fluid mechanic analyses, measurement advances, and a pool of educated graduate students are sought.

  7. Method for Estimating Operational Loads on Aerospace Structures Using Span-Wisely Distributed Surface Strains

    NASA Technical Reports Server (NTRS)

    Ko, William L.; Fleischer, Van Tran

    2013-01-01

    This report presents a new method for estimating operational loads (bending moments, shear loads, and torques) acting on slender aerospace structures using distributed surface strains (unidirectional strains). The surface strain-sensing stations are to be evenly distributed along each span-wise strain-sensing line. A depth-wise cross section of the structure along each strain-sensing line can then be considered as an imaginary embedded beam. The embedded beam was first evenly divided into multiple small domains with domain junctures matching the strain-sensing stations. The new method is comprised of two steps. The first step is to determine the structure stiffness (bending or torsion) using surface strains obtained from a simple bending (or torsion) loading case, for which the applied bending moment (or torque) is known. The second step is to use the strain-determined structural stiffness (bending or torsion), and a new set of surface strains induced by any other loading case to calculate the associated operational loads (bending moments, shear loads, or torques). Performance of the new method for estimating operational loads was studied in light of finite-element analyses of several example structures subjected to different loading conditions. The new method for estimating operational loads was found to be fairly accurate, and is very promising for applications to the flight load monitoring of flying vehicles with slender wings.

  8. Laser Surface Preparation and Bonding of Aerospace Structural Composites

    NASA Technical Reports Server (NTRS)

    Belcher, M. A.; Wohl, C. J.; Hopkins, J. W.; Connell, J. W.

    2010-01-01

    Adhesive bonds are critical to the integrity of built-up structures. Disbonds can often be detected but the strength of adhesion between surfaces in contact is not obtainable without destructive testing. Typically the number one problem in a bonded structure is surface contamination, and by extension, surface preparation. Standard surface preparation techniques, including grit blasting, manual abrasion, and peel ply, are not ideal because of variations in their application. Etching of carbon fiber reinforced plastic (CFRP) panels using a neodymium-doped yttrium aluminum garnet (Nd:YAG) laser appears to be a highly precise and promising way to both clean a composite surface prior to bonding and provide a bond-promoting patterned surface akin to peel ply without the inherent drawbacks from the same (i.e., debris and curvature). CFRP surfaces prepared using laser patterns conducive to adhesive bonding were compared to typical prebonding surface treatments through optical microscopy, contact angle goniometry, and post-bonding mechanical testing.

  9. Integrity assessment of preforms and thick textile reinforced composites for aerospace applications

    NASA Astrophysics Data System (ADS)

    Saboktakin Rizi, Abbasali

    Three-dimensional (3D) textile composites containing in-plane fibers and fibers oriented in the thickness direction offer some advantages over two-dimensional (2D) textile composites. These advantages include high delamination resistance and improved damage tolerance. Textile composites containing 3D textile preforms have mostly been developed by the aerospace industry for structural applications such as wing panels, landing gear, rocket nozzles, and the Orion capsule, and so forth. This thesis is devoted to structural integrity assessment of textile composites including 2D and 3D tufted composites by combining destructive and non-destructive techniques. In the first part of the thesis, non-destructive techniques including X-ray computed tomography (CT) and ultrasound-based techniques (UT) were used to detect two significant processinduced defects called fiber breakage and fabric misalignment. The second part focuses on studying of the influence of manufacturing defects introduced during the tufting process on the mechanical properties. Experimental results proved that X-ray CT facilitates the characterization of those two manufacturing defects as well as the architecture of the textile fabrics. Furthermore, mesoscale modeling of a 2D woven composite was successfully performed for the analysis of the fiber breakage defect influence and fiber architecture on wave propagation. Experimental results prove that tufting the preform assists in locking and restricting the yarn's movement in the preform. The threads used for tufting have a major influence on tensile strength, as stronger threads may give higher resistance. Tufting increases the compaction force due locking of fiber bundles, therefore, a higher compaction force is needed to obtain a fiber volume of up to 50 percent in comparison to an untufted preform. The drape behaviour of a tufted preform is influenced by tufting so that high drapability is observed for a tufted preform along with local variation of fiber

  10. High temperature resin matrix composites for aerospace structures

    NASA Technical Reports Server (NTRS)

    Davis, J. G., Jr.

    1980-01-01

    Accomplishments and the outlook for graphite-polyimide composite structures are briefly outlined. Laminates, skin-stiffened and honeycomb sandwich panels, chopped fiber moldings, and structural components were fabricated with Celion/LARC-160 and Celion/PMR-15 composite materials. Interlaminar shear and flexure strength data obtained on as-fabricated specimens and specimens that were exposed for 125 hours at 589 K indicate that epoxy sized and polyimide sized Celion graphite fibers exhibit essentially the same behavior in a PMR-15 matrix composite. Analyses and tests of graphite-polyimide compression and shear panels indicate that utilization in moderately loaded applications offers the potential for achieving a 30 to 50 percent reduction in structural mass compared to conventional aluminum panels. Data on effects of moisture, temperature, thermal cycling, and shuttle fluids on mechanical properties indicate that both LARC-160 and PMR-15 are suitable matrix materials for a graphite-polyimide aft body flap. No technical road blocks to building a graphite-polyimide composite aft body flap are identified.

  11. Scanning laser vibrometer for dynamic deflection shape characterization of aerospace structures

    NASA Astrophysics Data System (ADS)

    Oliver, David E.

    1995-06-01

    The Scanning Laser Vibrometer (SLV) is becoming widely used as a cost effective tool for automated vibration measurement and analysis of aerospace structures and components. Applications include developing techniques for identifying damage in commercial aircraft, analyzing damage initiation mechanisms during environmental testing of circuit boards and optimum locations for active vibration dampers. The primary advantage of the SLV is the speed with which vibrational velocity measurements can be made over an area. An SLV scan of a structure such as the interior of a fuselage, gathering multi-frequency phase and amplitude values at every point, can be accomplished in less than the time taken to attach and acquire data from a single accelerometer. Results are superimposed in color on a digitized video image of the area tested. Laser vibrometers that offer finer velocity resolution, wider operating range and higher linearity are now available in a fully automated scanning package with ultra-high optical sensitivity. This optical sensitivity for testing untreated areas such as flat black surfaces of graphite composites has been limited in the past to low frequencies and amplitudes. Low optical sensitivity has especially restricted applications such as damage detection -- until now.

  12. A Qualitative Program Evaluation of a Structured Leadership Mentoring Program at a Large Aerospace Corporation

    ERIC Educational Resources Information Center

    Teller, Romney P.

    2011-01-01

    The researcher utilized a qualitative approach to conduct a program evaluation of the organization where he is employed. The study intended to serve as a program evaluation for the structured in-house mentoring program at a large aerospace corporation (A-Corp). This program evaluation clarified areas in which the current mentoring program is…

  13. Frontier Aerospace Opportunities

    NASA Technical Reports Server (NTRS)

    Bushnell, Dennis M.

    2014-01-01

    Discussion and suggested applications of the many ongoing technology opportunities for aerospace products and missions, resulting in often revolutionary capabilities. The, at this point largely unexamined, plethora of possibilities going forward, a subset of which is discussed, could literally reinvent aerospace but requires triage of many possibilities. Such initial upfront homework would lengthen the Research and Development (R&D) time frame but could greatly enhance the affordability and performance of the evolved products and capabilities. Structural nanotubes and exotic energetics along with some unique systems approaches are particularly compelling.

  14. X-ray backscatter imaging for aerospace applications

    SciTech Connect

    Shedlock, Daniel; Edwards, Talion; Toh, Chin

    2011-06-23

    Scatter x-ray imaging (SXI) is a real time, digital, x-ray backscatter imaging technique that allows radiographs to be taken from one side of an object. This x-ray backscatter imaging technique offers many advantages over conventional transmission radiography that include single-sided access and extremely low radiation fields compared to conventional open source industrial radiography. Examples of some applications include the detection of corrosion, foreign object debris, water intrusion, cracking, impact damage and leak detection in a variety of material such as aluminum, composites, honeycomb structures, and titanium.

  15. High Volume Fraction Carbon Nanotube Composites for Aerospace Applications

    NASA Technical Reports Server (NTRS)

    Siochi, E. J.; Kim, J.-W.; Sauti, G.; Cano, R. J.; Wincheski, R. A.; Ratcliffe, J. G.; Czabaj, M.

    2016-01-01

    Reported mechanical properties of carbon nanotubes (CNTs) at the nanoscale suggest their potential to enable significantly lighter structures of interest for space applications. However, their utility depends on the retention of these properties in bulk material formats that permit practical fabrication of large structures. This presentation summarizes recent progress made to produce carbon nanotube composites with specific tensile properties that begin to rival those of carbon fiber reinforced polymer composites. CNT content in these nanocomposites was greater than 70% by weight. Tested nanocomposite specimens were fabricated from kilometers or tens of square meters of CNT, depending on the starting material format. Processing methods to yield these results, and characterization and testing to evaluate the performance of these composites will be discussed. The final objective is the demonstration of a CNT composite overwrapped pressure vessel to be flight tested in the Fall of 2016.

  16. Early stopping of aerospace medical trials: application of sequential principles.

    PubMed

    Kumar, K V; Powell, M R; Waligora, J M

    1994-06-01

    A two-period, crossover trial was conducted in the hypobaric chamber on human subjects to compare the influence of inflight exercise (experimental) and restricted activity (control) on altitude decompression sickness (DCS) during simulated extravehicular activities. Out of 39 pairs (total of 78 exposures), 4 cases of DCS occurred under control and 5 occurred under experimental conditions. Analysis of the crossover results showed that the P values for differences in DCS occurrence was 0.56. Under these circumstances, it was necessary to decide whether additional information would be obtained by accruing more subjects. This problem was examined by using a skew sequential design in which the "stopping rule" was based on an alpha of 0.05 (one-sided) and power of 80%. The result of this analysis was in favor of the null hypothesis, and the trial was terminated. The authors recommend the use of similar stopping rules in aerospace trials to optimize sample size without compromising statistical validity.

  17. Production Strategies for Production-Quality Parts for Aerospace Applications

    NASA Technical Reports Server (NTRS)

    Cawley, J. D.; Best, J. E.; Liu, Z.; Eckel, A. J.; Reed, B. D.; Fox, D. S.; Bhatt, R.; Levine, Stanley R. (Technical Monitor)

    2000-01-01

    A combination of rapid prototyping processes (3D Systems' stereolithography and Sanders Prototyping's ModelMaker) are combined with gelcasting to produce high quality silicon nitride components that were performance tested under simulated use conditions. Two types of aerospace components were produced, a low-force rocket thruster and a simulated airfoil section. The rocket was tested in a test stand using varying mixtures of H2 and O2, whereas the simulated airfoil was tested by subjecting it to a 0.3 Mach jet-fuel burner flame. Both parts performed successfully, demonstrating the usefulness of the rapid prototyping in efforts to effect materials substitution. In addition, the simulated airfoil was used to explore the possibility of applying thermal/environmental barrier coatings and providing for internal cooling of ceramic parts. It is concluded that this strategy for processing offers the ceramic engineer all the flexibility normally associated with investment casting of superalloys.

  18. Proceedings of the 4th Annual Workshop: Advances in Smart Materials for Aerospace Applications

    NASA Technical Reports Server (NTRS)

    Hardy, Robin C. (Editor); Simpson, Joycelyn O. (Editor)

    1996-01-01

    The objective of the Fourth Annual Conference on Advances in Smart Materials for Aerospace Applications was to provide a forum for technical dialogue on numerous topics in the area of smart materials. The proceedings presented herein represent the technical contributions of the participants of the workshop. Topics addressed include shape memory alloys, ferroelectrics, fiber optics, finite element simulation, and active control.

  19. A preliminary investigation of the potential applicability of the IPAD system to non-aerospace industry

    NASA Technical Reports Server (NTRS)

    Hulbert, L. E.

    1975-01-01

    A study of the applicability of the planned Integrated Programs for Aerospace-Vehicle Design (IPAD) system to the design activities of non-aerospace industries was carried out. It was determined that IPAD could be of significant benefit to a number of industries, with the most likely users being the heavy construction and automotive industries. Two additional short studies were initiated to investigate the possible impact of IPAD on a national energy program and on urban and regional planning activities of local and state governments. These initial studies indicated the possibility of significant payoff in these areas and the need for further investigations. It was also determined that utilization of IPAD by non-aerospace industries will probably involve a long stepwise process, since these industries maintain a policy of gradual introduction of new technology.

  20. Summary of the Active Microwave Workshop, chapter 1. [utilization in applications and aerospace programs

    NASA Technical Reports Server (NTRS)

    1975-01-01

    An overview is given of the utility, feasibility, and advantages of active microwave sensors for a broad range of applications, including aerospace. In many instances, the material provides an in-depth examination of the applicability and/or the technology of microwave remote sensing, and considerable documentation is presented in support of these techniques. An assessment of the relative strengths and weaknesses of active microwave sensor data indicates that satisfactory data are obtainable for several significant applications.

  1. The 27th Aerospace Mechanisms Symposium

    NASA Technical Reports Server (NTRS)

    Mancini, Ron (Compiler)

    1993-01-01

    The proceedings of the 27th Aerospace Mechanisms Symposium, which was held at ARC, Moffett Field, California, on 12-14 May 1993, are reported. Technological areas covered include the following: actuators, aerospace mechanism applications for ground support equipment, lubricants, latches, connectors, robotic mechanisms, and other mechanisms for large space structures.

  2. The 26th Aerospace Mechanisms Symposium

    NASA Technical Reports Server (NTRS)

    1992-01-01

    The proceedings of the 26th Aerospace Mechanisms Symposium, which was held at the Goddard Space Flight Center on May 13, 14, and 15, 1992 are reported. Technological areas covered include actuators, aerospace mechanism applications for ground support equipment, lubricants, latches, connectors and other mechanisms for large space structures.

  3. Laser Surface Preparation for Adhesive Bonding of Aerospace Structural Composites

    NASA Technical Reports Server (NTRS)

    Belcher, M. A.; Wohl, C. J.; Hopkins, J. W.; Connell, J. W.

    2010-01-01

    Adhesive bonds are critical to the integrity of built-up structures. Disbonds can often be detected but the strength of adhesion between surfaces in contact is not obtainable without destructive testing. Typically the number one problem in a bonded structure is surface contamination, and by extension, surface preparation. Standard surface preparation techniques, including grit blasting, manual abrasion, and peel ply, are not ideal because of variations in their application. Etching of carbon fiber reinforced plastic (CFRP) panels using a neodymium-doped yttrium aluminum garnet (Nd:YAG) laser appears to be a highly precise and promising way to both clean a composite surface prior to bonding and provide a bond-promoting patterned surface akin to peel ply without the inherent drawbacks from the same (i.e., debris and curvature). CFRP surfaces prepared using laser patterns conducive to adhesive bonding were compared to typical pre-bonding surface treatments through optical microscopy, contact angle goniometry, and post-bonding mechanical testing.

  4. Multifunctional Nanotube Polymer Nanocomposites for Aerospace Applications: Adhesion between SWCNT and Polymer Matrix

    NASA Technical Reports Server (NTRS)

    Park, Cheol; Wise, Kristopher E.; Kang, Jin Ho; Kim, Jae-Woo; Sauti, Godfrey; Lowther, Sharon E.; Lillehei, Peter T.; Smith, Michael W.; Siochi, Emilie J.; Harrison, Joycelyn S.; Jordan, Kevin

    2008-01-01

    Multifunctional structural materials can enable a novel design space for advanced aerospace structures. A promising route to multifunctionality is the use of nanotubes possessing the desired combination of properties to enhance the characteristics of structural polymers. Recent nanotube-polymer nanocomposite studies have revealed that these materials have the potential to provide structural integrity as well as sensing and/or actuation capabilities. Judicious selection or modification of the polymer matrix to promote donor acceptor and/or dispersion interactions can improve adhesion at the interface between the nanotubes and the polymer matrix significantly. The effect of nanotube incorporation on the modulus and toughness of the polymer matrix will be presented. Very small loadings of single wall nanotubes in a polyimide matrix yield an effective sensor material that responds to strain, stress, pressure, and temperature. These materials also exhibit significant actuation in response to applied electric fields. The objective of this work is to demonstrate that physical properties of multifunctional material systems can be tailored for specific applications by controlling nanotube treatment (different types of nanotubes), concentration, and degree of alignment.

  5. Mould design and manufacturing considerations of honeycomb biocomposites with transverse fibre direction for aerospace application

    NASA Astrophysics Data System (ADS)

    Manan, N. H.; Majid, D. L.; Romli, F. I.

    2016-10-01

    Sandwich structures with honeycomb core are known to significantly improve stiffness at lower weight and possess high flexural rigidity. They have found wide applications in aerospace as part of the primary structures, as well as the interior paneling and floors. High performance aluminum and aramid are the typical materials used for the purpose of honeycomb core whereas in other industries, materials such as fibre glass, carbon fibre, Nomex and also Kevlar reinforced with polymer are used. Recently, growing interest in developing composite structures with natural fibre reinforcement has also spurred research in natural fibre honeycomb material. The majority of the researches done, however, have generally emphasized on the usage of random chopped fibre and only a few are reported on development of honeycomb structure using unidirectional fibre as the reinforcement. This is mainly due to its processing difficulties, which often involve several stages to account for the arrangement of fibres and curing. Since the use of unidirectional fibre supports greater strength compared to random chopped fibre, a single-stage process in conjunction with vacuum infusion is suggested with a mould design that supports fibre arrangement in the direction of honeycomb loading.

  6. Some aspects of algorithm performance and modeling in transient thermal analysis of structures. [aerospace vehicle structures

    NASA Technical Reports Server (NTRS)

    Adelman, H. M.; Haftka, R. T.; Robinson, J. C.

    1982-01-01

    The status of an effort to increase the efficiency of calculating transient temperature fields in complex aerospace vehicle structures is described. The advantages and disadvantages of explicit and implicit algorithms are discussed. A promising set of implicit algorithms with variable time steps, known as the GEAR package is described. Four test problems, used for evaluating and comparing various algorithms, were selected and finite element models of the configurations are described. These problems include a space shuttle frame component, an insulated cylinder, a metallic panel for a thermal protection system, and a model of the space shuttle orbiter wing. Results generally indicate a preference for implicit oer explicit algorithms for solution of transient structural heat transfer problems when the governing equations are stiff.

  7. Advanced materials for aerospace and biomedical applications: New glasses for hermetic titanium seals

    SciTech Connect

    Brow, R.K.; Tallant, D.R.; Crowder, S.V.

    1996-11-01

    Titanium and titanium alloys have an outstanding strength-to-weight ratio and corrosion resistance and so are materials of choice for a variety of aerospace and biomedical applications. Such applications are limited by the lack of a viable hermetic glass sealing technology. Conventional silicate sealing glasses are readily reduced by titanium to form interfacial silicides that are incompatible with a robust glass/metal seal. Borate-based glasses undergo a similar thermochemistry and are reduced to a titanium boride. The kinetics of this reactions, however, are apparently slower and so a deleterious interface does not form. Chemically durable lanthanoborate glasses were examined as candidate sealing compositions. The compositions, properties, and structures of several alkaline earth, alumina, and titania lanthanoborate glass forming systems were evaluated and this information was used as the basis for a designed experiment to optimize compositions for Ti-sealing. A number of viable compositions were identified and sealing procedures established. Finally, glass formation, properties, and structure of biocompatible Fe{sub 2}O{sub 3}- and TiO{sub 2}-doped calcium phosphate systems were also evaluated.

  8. NASA-UVA Light Aerospace Alloy and Structures Technology Program: LA(2)ST

    NASA Technical Reports Server (NTRS)

    Gangloff, Richard P.; Haviland, John K.; Herakovich, Carl T.; Pilkey, Walter D.; Pindera, Marek-Jerzy; Scully, John R.; Stoner, Glenn E.; Thornton, Earl A.; Wawner, Franklin E., Jr.; Wert, John A.

    1993-01-01

    The NASA-UVA Light Aerospace Alloy and Structures Technology (LA(2)ST) Program continues a high level of activity, with projects being conducted by graduate students and faculty advisors in the Departments of Materials Science and Engineering, Civil Engineering and Applied Mechanics, and Mechanical and Aerospace Engineering at the University of Virginia. This work is funded by the NASA-Langley Research Center under Grant NAG-1-745. We report on progress achieved between July 1 and December 31, 1992. The objective of the LA(2)ST Program is to conduct interdisciplinary graduate student research on the performance of next generation, light weight aerospace alloys, composites and thermal gradient structures in collaboration with NASA-Langley researchers. Specific technical objectives are presented for each research project. We generally aim to produce relevant data and basic understanding of material mechanical response, corrosion behavior, and microstructure; new monolithic and composite alloys; advanced processing methods; new solid and fluid mechanics analyses; measurement advances; and critically, a pool of educated graduate students for aerospace technologies.

  9. NASA-UVA light aerospace alloy and structures technology program (LA2ST)

    NASA Technical Reports Server (NTRS)

    Gangloff, Richard P.; Scully, John R.; Starke, Edgar A., Jr.; Stoner, Glenn E.; Thornton, Earl A.; Wawner, Franklin E., Jr.; Wert, John A.

    1994-01-01

    The NASA-UVA Light Aerospace Alloy and Structures Technology (LA2ST) Program was initiated in 1986, and continues a high level of activity, with projects being conducted by graduate students and faculty advisors in the Departments of Materials Science and Engineering, and Mechanical and Aerospace Engineering at the University of Virginia. This work is funded by the NASA-Langley Research Center under Grant NAG-1-745. Here, we report on progress achieved between July 1 and December 31, 1993. The objective of the LA2ST Program is to conduct interdisciplinary graduate student research on the performance of next generation, light weight aerospace alloys, composites and thermal gradient structures in collaboration with NASA-Langley researchers. Specific technical objectives are presented for each research project. We generally aim to produce relevant data and basic understanding of material mechanical response, environmental/corrosion behavior, and microstructure; new monolithic and composite alloys; advanced processing methods; new solid and fluid mechanics analyses; measurement and modeling advances; and critically, a pool of educated graduate students for aerospace technologies.

  10. A Survey of Emerging Materials for Revolutionary Aerospace Vehicle Structures and Propulsion Systems

    NASA Technical Reports Server (NTRS)

    Harris, Charles E.; Shuart, Mark J.; Gray, Hugh R.

    2002-01-01

    The NASA Strategic Plan identifies the long-term goal of providing safe and affordable space access, orbital transfer, and interplanetary transportation capabilities to enable scientific research, human, and robotic exploration, and the commercial development of space. Numerous scientific and engineering breakthroughs will be required to develop the technology required to achieve this goal. Critical technologies include advanced vehicle primary and secondary structure, radiation protection, propulsion and power systems, fuel storage, electronics and devices, sensors and science instruments, and medical diagnostics and treatment. Advanced materials with revolutionary new capabilities are an essential element of each of these technologies. A survey of emerging materials with applications to aerospace vehicle structures and propulsion systems was conducted to assist in long-term Agency mission planning. The comprehensive survey identified materials already under development that could be available in 5 to 10 years and those that are still in the early research phase and may not be available for another 20 to 30 years. The survey includes typical properties, a description of the material and processing methods, the current development status, and the critical issues that must be overcome to achieve commercial viability.

  11. High Volume Fraction Carbon Nanotube Composites for Aerospace Applications

    NASA Technical Reports Server (NTRS)

    Siochi, Emilie J.; Kim, Jae-Woo; Sauti, Godfrey; Cano, Roberto J.; Wincheski, Russell A.; Ratcliffe, James G.; Czabaj, Michael; Jensen, Benjamin D.; Wise, Kristopher E.

    2015-01-01

    Reported nanoscale mechanical properties of carbon nanotubes (CNTs) suggest that their use may enable the fabrication of significantly lighter structures for use in space applications. To be useful in the fabrication of large structures, however, their attractive nanoscale properties must be retained as they are scaled up to bulk materials and converted into practically useful forms. Advances in CNT production have significantly increased the quantities available for use in manufacturing processes, but challenges remain with the retention of nanoscale properties in larger assemblies of CNTs. This work summarizes recent progress in producing carbon nanotube composites with tensile properties approaching those of carbon fiber reinforced polymer composites. These advances were achieved in nanocomposites with CNT content of 70% by weight. The processing methods explored to yield these CNT composite properties will be discussed, as will the characterization and test methods that were developed to provide insight into the factors that contribute to the enhanced tensile properties. Technology maturation was guided by parallel advancements in computational modeling tools that aided in the interpretation of experimental data.

  12. Applications of aerospace technology in biology and medicine

    NASA Technical Reports Server (NTRS)

    Bass, B.; Beall, H. C.; Brown, J. N., Jr.; Clingman, W. H.; Eakes, R. E.; Kizakevich, P. N.; Mccartney, M.; Rouse, D. J.

    1982-01-01

    Utilization of National Aeronautics and Space Administration (NASA) technology in medicine is discussed. The objective is best obtained by stimulation of the introduction of new or improved commercially available medical products incorporating aerospace technology. A bipolar donor/recipient model of medical technology transfer is presented to provide a basis for the team's methodology. That methodology is designed to: (1) identify medical problems and NASA technology that, in combination, constitute opportunities for successful medical products; (2) obtain the early participation of industry in the transfer process; and (3) obtain acceptance by the medical community of new medical products based on NASA technology. Two commercial transfers were completed: the Stowaway, a lightweight wheelchair that provides mobility for the disabled and elderly in the cabin of commercial aircraft, and Micromed, a portable medication infusion pump for the reliable, continuous infusion of medications such as heparin or insulin. The marketing and manufacturing factors critical to the commercialization of the lightweight walker incorporating composite materials were studied. Progress was made in the development and commercialization of each of the 18 currently active projects.

  13. High Resolution Aerospace Applications using the NASA Columbia Supercomputer

    NASA Technical Reports Server (NTRS)

    Mavriplis, Dimitri J.; Aftosmis, Michael J.; Berger, Marsha

    2005-01-01

    This paper focuses on the parallel performance of two high-performance aerodynamic simulation packages on the newly installed NASA Columbia supercomputer. These packages include both a high-fidelity, unstructured, Reynolds-averaged Navier-Stokes solver, and a fully-automated inviscid flow package for cut-cell Cartesian grids. The complementary combination of these two simulation codes enables high-fidelity characterization of aerospace vehicle design performance over the entire flight envelope through extensive parametric analysis and detailed simulation of critical regions of the flight envelope. Both packages. are industrial-level codes designed for complex geometry and incorpor.ats. CuStomized multigrid solution algorithms. The performance of these codes on Columbia is examined using both MPI and OpenMP and using both the NUMAlink and InfiniBand interconnect fabrics. Numerical results demonstrate good scalability on up to 2016 CPUs using the NUMAIink4 interconnect, with measured computational rates in the vicinity of 3 TFLOP/s, while InfiniBand showed some performance degradation at high CPU counts, particularly with multigrid. Nonetheless, the results are encouraging enough to indicate that larger test cases using combined MPI/OpenMP communication should scale well on even more processors.

  14. Modeling, Detection, and Disambiguation of Sensor Faults for Aerospace Applications

    NASA Technical Reports Server (NTRS)

    Balaban, Edward; Saxena, Abhinav; Bansal, Prasun; Goebel, Kai F.; Curran, Simon

    2009-01-01

    Sensor faults continue to be a major hurdle for systems health management to reach its full potential. At the same time, few recorded instances of sensor faults exist. It is equally difficult to seed particular sensor faults. Therefore, research is underway to better understand the different fault modes seen in sensors and to model the faults. The fault models can then be used in simulated sensor fault scenarios to ensure that algorithms can distinguish between sensor faults and system faults. The paper illustrates the work with data collected from an electro-mechanical actuator in an aerospace setting, equipped with temperature, vibration, current, and position sensors. The most common sensor faults, such as bias, drift, scaling, and dropout were simulated and injected into the experimental data, with the goal of making these simulations as realistic as feasible. A neural network based classifier was then created and tested on both experimental data and the more challenging randomized data sequences. Additional studies were also conducted to determine sensitivity of detection and disambiguation efficacy to severity of fault conditions.

  15. Prediction of three sigma maximum dispersed density for aerospace applications

    NASA Technical Reports Server (NTRS)

    Charles, Terri L.; Nitschke, Michael D.

    1993-01-01

    Free molecular heating (FMH) is caused by the transfer of energy during collisions between the upper atmosphere molecules and a space vehicle. The dispersed free molecular heating on a surface is an important constraint for space vehicle thermal analyses since it can be a significant source of heating. To reduce FMH to a spacecraft, the parking orbit is often designed to a higher altitude at the expense of payload capability. Dispersed FMH is a function of both space vehicle velocity and atmospheric density, however, the space vehicle velocity variations are insignificant when compared to the atmospheric density variations. The density of the upper atmosphere molecules is a function of altitude, but also varies with other environmental factors, such as solar activity, geomagnetic activity, location, and time. A method has been developed to predict three sigma maximum dispersed density for up to 15 years into the future. This method uses a state-of-the-art atmospheric density code, MSIS 86, along with 50 years of solar data, NASA and NOAA solar activity predictions for the next 15 years, and an Aerospace Corporation correlation to account for density code inaccuracies to generate dispersed maximum density ratios denoted as 'K-factors'. The calculated K-factors can be used on a mission unique basis to calculate dispersed density, and hence dispersed free molecular heating rates. These more accurate K-factors can allow lower parking orbit altitudes, resulting in increased payload capability.

  16. Development and analysis of insulation constructions for aerospace wiring applications

    NASA Astrophysics Data System (ADS)

    Slenski, George A.; Woodford, Lynn M.

    1993-03-01

    The Wright Laboratory Materials Directorate at WPAFB, Ohio recently completed a research and development program under contract with the McDonnell Douglas Aerospace Company, St. Louis, Missouri. Program objectives were to develop wire insulation performance requirements, evaluate candidate insulations, and prepare preliminary specification sheets on the most promising candidates. Aircraft wiring continues to be a high maintenance item and a major contributor to electrically-related aircraft mishaps. Mishap data on aircraft show that chafing of insulation is the most common mode of wire failure. Improved wiring constructions are expected to increase aircraft performance and decrease costs by reducing maintenance actions. In the laboratory program, new insulation constructions were identified that had overall improved performance in evaluation tests when compared to currently available MIL-W-81381 and MIL-W-22759 wiring. These insulations are principally aromatic polyimide and crosslinked ethylene tetrafluoroethylene (ETFE), respectively. Candidate insulations identified in preliminary specification sheets were principally fluoropolymers with a polyimide inner layer. Examples of insulation properties evaluated included flammability, high temperature mechanical and electrical performance, fluid immersion, and susceptibility to arc propagation under applied power chafing conditions. Potential next generation wire insulation materials are also reviewed.

  17. Standardization of shape memory alloy test methods toward certification of aerospace applications

    NASA Astrophysics Data System (ADS)

    Hartl, D. J.; Mabe, J. H.; Benafan, O.; Coda, A.; Conduit, B.; Padan, R.; Van Doren, B.

    2015-08-01

    The response of shape memory alloy (SMA) components employed as actuators has enabled a number of adaptable aero-structural solutions. However, there are currently no industry or government-accepted standardized test methods for SMA materials when used as actuators and their transition to commercialization and production has been hindered. This brief fast track communication introduces to the community a recently initiated collaborative and pre-competitive SMA specification and standardization effort that is expected to deliver the first ever regulatory agency-accepted material specification and test standards for SMA as employed as actuators for commercial and military aviation applications. In the first phase of this effort, described herein, the team is working to review past efforts and deliver a set of agreed-upon properties to be included in future material certification specifications as well as the associated experiments needed to obtain them in a consistent manner. Essential for the success of this project is the participation and input from a number of organizations and individuals, including engineers and designers working in materials and processing development, application design, SMA component fabrication, and testing at the material, component, and system level. Going forward, strong consensus among this diverse body of participants and the SMA research community at large is needed to advance standardization concepts for universal adoption by the greater aerospace community and especially regulatory bodies. It is expected that the development and release of public standards will be done in collaboration with an established standards development organization.

  18. Advances in SiC/SiC Composites for Aerospace Applications

    NASA Technical Reports Server (NTRS)

    DiCarlo, James A.

    2006-01-01

    In recent years, supported by a variety of materials development programs, NASA Glenn Research Center has significantly increased the thermostructural capability of SiC/SiC composite materials for high-temperature aerospace applications. These state-of-the-art advances have occurred in every key constituent of the composite: fiber, fiber coating, matrix, and environmental barrier coating, as well as processes for forming the fiber architectures needed for complex-shaped components such as turbine vanes for gas turbine engines. This presentation will briefly elaborate on the nature of these advances in terms of performance data and underlying mechanisms. Based on a list of first-order property goals for typical high-temperature applications, key data from a variety of laboratory tests are presented which demonstrate that the NASA-developed constituent materials and processes do indeed result in SiC/SiC systems with the desired thermal and structural capabilities. Remaining process and microstructural issues for further property enhancement are discussed, as well as on-going approaches at NASA to solve these issues. NASA efforts to develop physics-based property models that can be used not only for component design and life modeling, but also for constituent material and process improvement will also be discussed.

  19. Applications of aerospace technology in biology and medicine

    NASA Technical Reports Server (NTRS)

    1973-01-01

    The results are reported of the medically related activities of the NASA Application Team Program at the Research Triangle Institute. Fourteen medical organizations are presently participating in the RTI Application Team Program: The accomplishments of the Research Triangle Institute Application Team during the reporting period were as follows: The team identified 21 new problems for investigation, accomplished 4 technology applications and 3 potential technology applications, closed 21 old problems, and on February 28, 1973, had a total of 57 problems under active investigation.

  20. The 24th Aerospace Mechanisms Symposium

    NASA Technical Reports Server (NTRS)

    1990-01-01

    The proceedings of the symposium are reported. Technological areas covered include actuators, aerospace mechanism applications for ground support equipment, lubricants, latches, connectors, and other mechanisms for large space structures.

  1. Microfabricated hydrogen sensor technology for aerospace and commercial applications

    NASA Astrophysics Data System (ADS)

    Hunter, Gary W.; Bickford, R. L.; Jansa, E. D.; Makel, D. B.; Liu, C. C.; Wu, Q. H.; Powers, W. T.

    1994-08-01

    Leaks on the Space Shuttle while on the Launch Pad have generated interest in hydrogen leak monitoring technology. An effective leak monitoring system requires reliable hydrogen sensors, hardware, and software to monitor the sensors. The system should process the sensor outputs and provide real-time leak monitoring information to the operator. This paper discusses the progress in developing such a complete leak monitoring system. Advanced microfabricated hydrogen sensors are being fabricated at Case Western Reserve University (CWRU) and tested at NASA Lewis Research Center (LeRC) and Gencorp Aerojet (Aerojet). Changes in the hydrogen concentrations are detected using a PdAg on silicon Schottky diode structure. Sensor temperature control is achieved with a temperature sensor and heater fabricated onto the sensor chip. Results of the characterization of these sensors are presented. These sensors can detect low concentrations of hydrogen in inert environments with high sensitivity and quick response time. Aerojet is developing the hardware and software for a multipoint leak monitoring system designed to provide leak source and magnitude information in real time. The monitoring system processes data from the hydrogen sensors and presents the operator with a visual indication of the leak location and magnitude. Work has commenced on integrating the NASA LeRC-CWRU hydrogen sensors with the Aerojet designed monitoring system. Although the leak monitoring system was designed for hydrogen propulsion systems, the possible applications of this monitoring system are wide ranged. Possible commercialization of the system will also be discussed.

  2. Microfabricated hydrogen sensor technology for aerospace and commercial applications

    NASA Astrophysics Data System (ADS)

    Hunter, Gary W.; Bickford, Randall L.; Jansa, E. D.; Makel, Darby B.; Liu, Chung-Chiun; Wu, Q. H.; Powers, William T.

    1994-10-01

    Leaks on the Space Shuttle while on the Launch Pad have generated interest in hydrogen leak monitoring technology. An effective leak monitoring system requires reliable hydrogen sensors, hardware, and software to monitor the sensors. The system should process the sensor outputs and provide real-time leak monitoring information to the operator. This paper discusses the progress in developing such a complete leak monitoring system. Advanced microfabricated hydrogen sensors are being fabricated at Case Western Reserve University (CWRU) and tested at NASA Lewis Research Center (LeRC) and Gencorp Aerojet (Aerojet). Changes in the hydrogen concentrations are detected using a PdAg on silicon Schottky diode structure. Sensor temperature control is achieved with a temperature sensor and heater fabricated onto the sensor chip. Results of the characterization of these sensors are presented. These sensors can detect low concentrations of hydrogen in inert environments with high sensitivity and quick response time. Aerojet is developing the hardware and software for a multipoint leak monitoring system designed to provide leak source and magnitude information in real time. The monitoring system processes data from the hydrogen sensors and presents the operator with a visual indication of the leak location and magnitude. Work has commenced on integrating the NASA LeRC-CWRU hydrogen sensors with the Aerojet designed monitoring system. Although the leak monitoring system was designed for hydrogen propulsion systems, the possible applications of this monitoring system are wide ranged. Possible commercialization of the system will also be discussed.

  3. Evaluation of a high-temperature adhesive for aerospace structural bonding

    SciTech Connect

    Falcone, A.; Pate, K.D.; Cao, T.Q.; Hsu, G.F.; Rogalski, M.E.

    1996-12-31

    High-temperature polymeric adhesives are required for many new aerospace applications, and such adhesives must possess both processability for bonding as well as durability for elevated temperature service. Evaluation of one candidate adhesive, based on phenylethynyl terminated imide oligomers (PETI) developed at the NASA Langley Research Center, for titanium bonding is described here and includes a discussion of processing, and physical and mechanical properties. Mechanical testing included single lap shear, wedge-crack extension, climbing drum peel, and flatwise tension for honeycomb sandwich. Thermal aging with and without fluids was conducted for up to 5,000 hours for preliminary short term durability testing. Excellent processability and mechanical performance was obtained from PETI adhesive films, including adhesive films produced with production equipment in production scale batches. Processability and elevated temperature durability indicate that PETI resinbased adhesives are promising candidates for demanding high-temperature aerospace applications.

  4. Combined electromechanical impedance and fiber optic diagnosis of aerospace structures

    NASA Astrophysics Data System (ADS)

    Schlavin, Jon; Zagrai, Andrei; Clemens, Rebecca; Black, Richard J.; Costa, Joey; Moslehi, Behzad; Patel, Ronak; Sotoudeh, Vahid; Faridian, Fereydoun

    2014-03-01

    Electromechanical impedance is a popular diagnostic method for assessing structural conditions at high frequencies. It has been utilized, and shown utility, in aeronautic, space, naval, civil, mechanical, and other types of structures. By contrast, fiber optic sensing initially found its niche in static strain measurement and low frequency structural dynamic testing. Any low frequency limitations of the fiber optic sensing, however, are mainly governed by its hardware elements. As hardware improves, so does the bandwidth (frequency range * number of sensors) provided by the appropriate enabling fiber optic sensor interrogation system. In this contribution we demonstrate simultaneous high frequency measurements using fiber optic and electromechanical impedance structural health monitoring technologies. A laboratory specimen imitating an aircraft wing structure, incorporating surfaces with adjustable boundary conditions, was instrumented with piezoelectric and fiber optic sensors. Experiments were conducted at different structural boundary conditions associated with deterioration of structural health. High frequency dynamic responses were collected at multiple locations on a laboratory wing specimen and conclusions were drawn about correspondence between structural damage and dynamic signatures as well as correlation between electromechanical impedance and fiber optic sensors spectra. Theoretical investigation of the effect of boundary conditions on electromechanical impedance spectra is presented and connection to low frequency structural dynamics is suggested. It is envisioned that acquisition of high frequency structural dynamic responses with multiple fiber optic sensors may open new diagnostic capabilities for fiber optic sensing technologies.

  5. Development of Microfabricated Chemical Gas Sensors and Sensor Arrays for Aerospace Applications

    NASA Technical Reports Server (NTRS)

    Hunter, G. W.; Neudeck, P. G.; Fralick, G.; Thomas, V.; Liu, C. C.; Wu, W. H.; Ward, B.; Makel, D.

    2002-01-01

    Aerospace applications require the development of chemical sensors with capabilities beyond those of commercially available sensors. In particular, factors such as minimal sensor size, weight, and power consumption are particularly important. Development areas which have potential aerospace applications include launch vehicle leak detection, engine health monitoring, fire detection, and environmental monitoring. Sensor development for these applications is based on progress in three types of technology: 1) Micromachining and microfabrication (Microsystem) technology to fabricate miniaturized sensors. 2) The use of nanocrystalline materials to develop sensors with improved stability combined with higher sensitivity. 3) The development of high temperature semiconductors, especially silicon carbide. However, due to issues of selectivity and cross-sensitivity, individual sensors are limited in the amount of information that they can provide in environments that contain multiple chemical species. Thus, sensor arrays are being developed to address detection needs in such multi-species environments. This paper discusses the needs of space applications as well as the point-contact sensor technology and sensor arrays being developed to address these needs. Sensors to measure hydrogen, hydrocarbons, hydrazine, nitrogen oxides (NO,), carbon monoxide, oxygen, and carbon dioxide are being developed as well as arrays for leak, fire, and emissions detection. Demonstrations of the technology will also be discussed. It is concluded that microfabricated sensor technology has significant potential for use in a range of aerospace applications.

  6. Applications of aerospace technology in biology and medicine

    NASA Technical Reports Server (NTRS)

    Wooten, F. T.

    1972-01-01

    The results are presented of the medically related activities of the NASA Application Team Program at the Research Triangle Institute. The accomplishments of the Research Triangle Institute Application Team during the reporting period are as follows: The team has identified 44 new problems for investigation, has accomplished 8 technology applications and 8 potential technology applications, has closed 88 old problems, and reactivated 3 old problems, and on August 31, 1972, has a total of 57 problems under active investigation.

  7. Experimental Modal Analysis and Dynaic Strain Fiber Bragg Gratings for Structural Health Monitoring of Composite Aerospace Structures

    NASA Astrophysics Data System (ADS)

    Panopoulou, A.; Fransen, S.; Gomez Molinero, V.; Kostopoulos, V.

    2012-07-01

    The objective of this work is to develop a new structural health monitoring system for composite aerospace structures based on dynamic response strain measurements and experimental modal analysis techniques. Fibre Bragg Grating (FBG) optical sensors were used for monitoring the dynamic response of the composite structure. The structural dynamic behaviour has been numerically simulated and experimentally verified by means of vibration testing. The hypothesis of all vibration tests was that actual damage in composites reduces their stiffness and produces the same result as mass increase produces. Thus, damage was simulated by slightly varying locally the mass of the structure at different zones. Experimental modal analysis based on the strain responses was conducted and the extracted strain mode shapes were the input for the damage detection expert system. A feed-forward back propagation neural network was the core of the damage detection system. The features-input to the neural network consisted of the strain mode shapes, extracted from the experimental modal analysis. Dedicated training and validation activities were carried out based on the experimental results. The system showed high reliability, confirmed by the ability of the neural network to recognize the size and the position of damage on the structure. The experiments were performed on a real structure i.e. a lightweight antenna sub- reflector, manufactured and tested at EADS CASA ESPACIO. An integrated FBG sensor network, based on the advantage of multiplexing, was mounted on the structure with optimum topology. Numerical simulation of both structures was used as a support tool at all the steps of the work. Potential applications for the proposed system are during ground qualification extensive tests of space structures and during the mission as modal analysis tool on board, being able via the FBG responses to identify a potential failure.

  8. Cyber Technology for Materials and Structures in Aeronautics and Aerospace

    NASA Technical Reports Server (NTRS)

    Pipes, R. Byron

    2002-01-01

    The evolution of composites applications in aeronautics from 1970 to the present is discussed. The barriers and challenges to economic application and to certification are presented and recommendations for accelerated development are outlined. The potential benefits of emerging technologies to aeronautics and their foundation in composite materials are described and the resulting benefits in vehicle take off gross weight are quantified. Finally, a 21st century vision for aeronautics in which human mobility is increased by an order of magnitude is articulated.

  9. An Inverse Interpolation Method Utilizing In-Flight Strain Measurements for Determining Loads and Structural Response of Aerospace Vehicles

    NASA Technical Reports Server (NTRS)

    Shkarayev, S.; Krashantisa, R.; Tessler, A.

    2004-01-01

    An important and challenging technology aimed at the next generation of aerospace vehicles is that of structural health monitoring. The key problem is to determine accurately, reliably, and in real time the applied loads, stresses, and displacements experienced in flight, with such data establishing an information database for structural health monitoring. The present effort is aimed at developing a finite element-based methodology involving an inverse formulation that employs measured surface strains to recover the applied loads, stresses, and displacements in an aerospace vehicle in real time. The computational procedure uses a standard finite element model (i.e., "direct analysis") of a given airframe, with the subsequent application of the inverse interpolation approach. The inverse interpolation formulation is based on a parametric approximation of the loading and is further constructed through a least-squares minimization of calculated and measured strains. This procedure results in the governing system of linear algebraic equations, providing the unknown coefficients that accurately define the load approximation. Numerical simulations are carried out for problems involving various levels of structural approximation. These include plate-loading examples and an aircraft wing box. Accuracy and computational efficiency of the proposed method are discussed in detail. The experimental validation of the methodology by way of structural testing of an aircraft wing is also discussed.

  10. Military handbook: Metallic materials and elements for aerospace vehicle structures, volume 1

    NASA Astrophysics Data System (ADS)

    1994-11-01

    Since many aerospace companies manufacture both commercial and military products, the standardization of metallic materials design data, which are acceptable to government procuring or certification agencies, is very beneficial to those manufacturers as well as governmental agencies. Although the design requirements for military and commercial products may differ greatly, the required design values for the strength of materials and elements and other needed material characteristics are often identical. Therefore this publication is to provide standardized design values and related design information for metallic materials and structural elements used in aerospace structures. The data contained herein or from approved items in the minutes of MIL-RDBK-5 coordination meetings are acceptable to the Air Force, the Navy, the Army, and the Federal Aviation Administration. Approval by the procuring or certificating agency must be obtained for the use of design values for products not contained herein.

  11. Probabilistic structural analysis of aerospace components using NESSUS

    NASA Technical Reports Server (NTRS)

    Shiao, Michael C.; Nagpal, Vinod K.; Chamis, Christos C.

    1988-01-01

    Probabilistic structural analysis of a Space Shuttle main engine turbopump blade is conducted using the computer code NESSUS (numerical evaluation of stochastic structures under stress). The goal of the analysis is to derive probabilistic characteristics of blade response given probabilistic descriptions of uncertainties in blade geometry, material properties, and temperature and pressure distributions. Probability densities are derived for critical blade responses. Risk assessment and failure life analysis is conducted assuming different failure models.

  12. Moving Aerospace Structural Design Practice to a Load and Resistance Factor Approach

    NASA Technical Reports Server (NTRS)

    Larsen, Curtis E.; Raju, Ivatury S.

    2016-01-01

    Aerospace structures are traditionally designed using the factor of safety (FOS) approach. The limit load on the structure is determined and the structure is then designed for FOS times the limit load - the ultimate load. Probabilistic approaches utilize distributions for loads and strengths. Failures are predicted to occur in the region of intersection of the two distributions. The load and resistance factor design (LRFD) approach judiciously combines these two approaches by intensive calibration studies on loads and strength to result in structures that are efficient and reliable. This paper discusses these three approaches.

  13. Applications of aerospace technology in the public sector

    NASA Technical Reports Server (NTRS)

    Anuskiewicz, T.; Johnston, J.; Zimmerman, R. R.

    1971-01-01

    Current activities of the program to accelerate specific applications of space related technology in major public sector problem areas are summarized for the period 1 June 1971 through 30 November 1971. An overview of NASA technology, technology applications, and supporting activities are presented. Specific technology applications in biomedicine are reported including cancer detection, treatment and research; cardiovascular diseases, diagnosis, and treatment; medical instrumentation; kidney function disorders, treatment, and research; and rehabilitation medicine.

  14. Development of aerospace nursing.

    PubMed

    Barron, N J

    1975-04-01

    In the initial development, the primary purpose of the USAF aerospace nursing program was to prepare the nurse to function as an integral member of the aerospace medical team in support of bioastronautics, occupational health and aerospace medical research programs. The absence of an expanded manned space program has required the aerospace nurse to redirect her energies toward the immediate needs of the aerospace medicine program. Many of the aerospace nurse's more specific functions are dependent upon the mission objectives of the command and military base to which she is assigned. Aerospace nursing reflects a concern for the total health needs of the Air Force community and the application of a holistic approach. It includes all aspects of health and all environmental hazards which alter health. The development of aerospace nursing paves the way for this expanded view of nursing practice.

  15. A new SMART sensing system for aerospace structures

    NASA Astrophysics Data System (ADS)

    Zhang, David C.; Yu, Pin; Beard, Shawn; Qing, Peter; Kumar, Amrita; Chang, Fu-Kuo

    2007-04-01

    It is essential to ensure the safety and reliability of in-service structures such as unmanned vehicles by detecting structural cracking, corrosion, delamination, material degradation and other types of damage in time. Utilization of an integrated sensor network system can enable automatic inspection of such damages ultimately. Using a built-in network of actuators and sensors, Acellent is providing tools for advanced structural diagnostics. Acellent's integrated structural health monitoring system consists of an actuator/sensor network, supporting signal generation and data acquisition hardware, and data processing, visualization and analysis software. This paper describes the various features of Acellent's latest SMART sensing system. The new system is USB-based and is ultra-portable using the state-of-the-art technology, while delivering many functions such as system self-diagnosis, sensor diagnosis, through-transmission mode and pulse-echo mode of operation and temperature measurement. Performance of the new system was evaluated for assessment of damage in composite structures.

  16. Advancement and Implementation of Integrated Computational Materials Engineering (ICME) for Aerospace Applications

    DTIC Science & Technology

    2010-03-01

    companies within the aerospace industry have internal materials models, often proprietary, based on phenomenological, statistical, and neural network...distributions) it also applies to some mechanical properties (e.g., measurement of elevated temperature dwell fatigue under certain environmental conditions...many, if not all, near-term integrated ICME applications can be integrated the old-fashion-way by piping information between software programs

  17. Space benefits: The secondary application of aerospace technology in other sectors of the economy

    NASA Technical Reports Server (NTRS)

    1976-01-01

    A benefits briefing notebook is presented for the NASA Technology Utilization Office in which 515 applications of NASA aerospace technology to other sections of the economy are described. An overview of technology transfer is given. Benefit cases are cited in 19 categories along with pertinent information, such as communication link, DRI transfer example file, and individual case number. General, organization, geographic, and field center indexes are provided.

  18. Transducer technology transfer to bio-engineering applications. [aerospace stress transducer for heart function analysis

    NASA Technical Reports Server (NTRS)

    Duran, E. N.; Lewis, G. W.; Feldstein, C.; Corday, E.; Meerbaum, S.; Lang, T.

    1973-01-01

    The results of a technology transfer of a miniature unidirectional stress transducer, developed for experimental stress analysis in the aerospace field, to applications in bioengineering are reported. By modification of the basic design and innovations in attachment techniques, the transducer was successfully used in vivo on the myocardium of large dogs to record the change in contractile force due to coronary occlusion, reperfusion, and intervention.

  19. Rapid Inspection of Aerospace Structures - Is It Autonomous Yet?

    NASA Technical Reports Server (NTRS)

    Bar-Cohen, Yoseph; Backes, Paul; Joffe, Benjamin

    1996-01-01

    The trend to increase the usage of aging aircraft added a great deal of urgency to the ongoing need for low-cost, rapid, simple-to-operate, reliable and efficient NDE methods for detection and characterization of flaws in aircraft structures. In many cases, the problem of inspection is complex due to the limitation of current technology and the need to disassemble aircraft structures and testing them in lab conditions. To overcome these limitations, reliable field inspection tools are being developed for rapid NDE of large and complex-shape structures, that can operate at harsh, hostal and remote conditions with minimum human interface. In recent years, to address the need for rapid inspection in field conditions, numerous portable scanners were developed using NDE methods, including ultrasonics, shearography, thermography. This paper is written with emphasis on ultrasonic NDE scanners, their evolution and the expected direction of growth.

  20. Applications of aerospace technology in biology and medicine

    NASA Technical Reports Server (NTRS)

    Brown, J. N.

    1974-01-01

    The results of the medically related activities of the NASA Application Team Program at the Research Triangle Institute are presented. The RTI team, a multidisciplinary team of scientists and engineers, acted as an information and technology interface between NASA and individuals, institutions, and agencies involved in biomedical research and clinical medicine. The Team has identified 40 new problems for investigation, has accomplished 7 technology applications, 6 potential technology application, 4 impacts, has closed 54 old problems, and has a total of 47 problems under active investigation.

  1. The automated strength-aeroelastic design of aerospace structures program

    NASA Technical Reports Server (NTRS)

    Johnson, E. H.; Venkayya, V. B.

    1984-01-01

    An ongoing program whose goal is to develop an automated procedure that can assist in the preliminary design of aircraft and space structures is described. The approach and capabilities that are to be included in the final procedures are descussed. By using proven engineering software as a basis for the project, a reliable and interdisciplinary procedure is developed. The use of a control language for module sequencing and execution permits efficient development of the procedure and gives the user significant flexibility in altering or enhancing the procedure. The data base system provides reliable and efficient access to the large amounts of interrelated data required in an enterprise of this sort. In addition, the data base allows interfacing with existing pre- and post-processors in an almost trivial manner. Altogether, the procedure promises to be of considerable utility to preliminary structural design teams.

  2. Shock-Induced Turbulence and Acoustic Loading on Aerospace Structures

    DTIC Science & Technology

    2015-08-22

    shockwave . The effects of grid resolution was investigated using three different grids (see Table 1). Each level of grid refinement used a smaller y...turbulent inflow technique. Past the shockwave front, the grid refinement appears to have little to no effect on the structure of the vortices...the interaction of the separation bubble and shockwave . The most important factor that determines the physical processes occurring here is the

  3. Cyber Technology for Materials and Structures in Aeronautics and Aerospace

    NASA Technical Reports Server (NTRS)

    Pipes, R. Byron

    1999-01-01

    This report summarizes efforts undertaken during the 1998-99 program year and includes a survey of the field of computational mechanics, a discussion of biomimetics and intelligent simulation, a survey of the field of biomimetics, an illustration of biomimetics and computational mechanics through the example of the high performance composite tensile structure. In addition, the preliminary results of a state-of-the art survey of composite materials technology is presented.

  4. Aerospace Structures Technology Damping Design Guide. Volume 2. Design Guide

    DTIC Science & Technology

    1985-12-01

    could be encountered in the future, Includes the large truss type space structures when assembled with clip -on types of joints. The damping in these...a harmonic force F cos ut, the mass displacement response is given by v(t) - Vocos (4t - (3.6) 3-12 where voK ’f T- Il + r - and ( rn Tan - 2 (..-jf

  5. Environmentally Assisted Cracking Properties of AA7249 Extrusions for Aerospace Applications

    DTIC Science & Technology

    2007-11-02

    USNA Chemistry Department for allowing me access to their DSC unit. Dr. Iulian Gheorghe ( ALU Menziken Aerospace / Universal Alloy Corporation) not...that environmental attacks is now becoming a significant concern. Structural components in the P-3C are currently composed of aluminum alloy AA7075-T6...effects of processing on wide panel extrusions. The results of this study will contribute to the ongoing evaluation of these alloys for replacement

  6. Use of 3X3 integrated optic polarizer/splitters for a smart aerospace plane structure

    NASA Astrophysics Data System (ADS)

    Seshamani, Ramani; Alex, T. K.

    1991-10-01

    A fiber-optic/integrated optic optoelectronic neural computer approach to the design of an 'intelligent' aerospace structure is described, and the methodology of the approach is defined. A source consisting of a strained-layer QW laser emitting 100 micro-W at 978 nm and an Er-doped single-mode polarization preserving fiber laser with a gain of 3.9 dB/mW is assumed. The SNR for the aerospace plane is calculated with 49 sensing arms. A 441-path splitter is required; this is designed using an eight-stage multipath coupler based on a 3X3 polarizer/splitter as the basic repeating element. A surface-mounted implementation is suggested, which includes a 448-path switch, an integrated-optic coupler, a detector, an ADC, and a processor.

  7. Analysis of fatigue, fatique-crack propagation, and fracture data. [design of metallic aerospace structural components

    NASA Technical Reports Server (NTRS)

    Jaske, C. E.; Feddersen, C. E.; Davies, K. B.; Rice, R. C.

    1973-01-01

    Analytical methods have been developed for consolidation of fatigue, fatigue-crack propagation, and fracture data for use in design of metallic aerospace structural components. To evaluate these methods, a comprehensive file of data on 2024 and 7075 aluminums, Ti-6A1-4V, and 300M and D6Ac steels was established. Data were obtained from both published literature and unpublished reports furnished by aerospace companies. Fatigue and fatigue-crack-propagation analyses were restricted to information obtained from constant-amplitude load or strain cycling of specimens in air at room temperature. Fracture toughness data were from tests of center-cracked tension panels, part-through crack specimens, and compact-tension specimens.

  8. A generalized concept for cost-effective structural design. [Statistical Decision Theory applied to aerospace systems

    NASA Technical Reports Server (NTRS)

    Thomas, J. M.; Hawk, J. D.

    1975-01-01

    A generalized concept for cost-effective structural design is introduced. It is assumed that decisions affecting the cost effectiveness of aerospace structures fall into three basic categories: design, verification, and operation. Within these basic categories, certain decisions concerning items such as design configuration, safety factors, testing methods, and operational constraints are to be made. All or some of the variables affecting these decisions may be treated probabilistically. Bayesian statistical decision theory is used as the tool for determining the cost optimum decisions. A special case of the general problem is derived herein, and some very useful parametric curves are developed and applied to several sample structures.

  9. NASA-UVA light aerospace alloy and structures technology program (LA2ST)

    NASA Technical Reports Server (NTRS)

    Starke, Edgar A., Jr.; Gangloff, Richard P.; Herakovich, Carl T.; Scully, John R.; Shiflet, Gary J.; Stoner, Glenn E.; Wert, John A.

    1995-01-01

    The NASA-UVa Light Aerospace Alloy and Structures Technology (LA2ST) Program was initiated in 1986 and continues with a high level of activity. Projects are being conducted by graduate students and faculty advisors in the Department of Materials Science and Engineering, as well as in the Department of Civil Engineering and Applied Mechanics, at the University of Virginia. Here, we report on progress achieved between July 1 and December 31, 1994. The objective of the LA2ST Program is to conduct interdisciplinary graduate student research on the performance of next generation, light-weight aerospace alloys, composites and thermal gradient structures in collaboration with NASA-Langley researchers. Specific technical objectives are presented for each research project. We generally aim to produce relevant data and basic understanding of material mechanical response, environmental/corrosion behavior, and microstructure; new monolithic and composite alloys; advanced processing methods; new solid and fluid mechanics analyses; measurement and modeling advances; and a pool of educated graduate students for aerospace technologies.

  10. NASA-UVA Light Aerospace Alloy and Structures Technology Program (LA2ST)

    NASA Technical Reports Server (NTRS)

    Gangloff, Richard P.

    1994-01-01

    The NASA-UVA Light Aerospace Alloy and Structures Technology (LA2ST) Program was initiated in 1986 and continues with a high level of activity. Projects are being conducted by graduate students and faculty advisors in the Department of Materials Science and Engineering, as well as in the Department of Civil Engineering and Applied Mechanics, at the University of Virginia. This work is funded by the NASA-Langley Research Center under Grant NAG-1-745. Here, we report on progress achieved between January 1 and June 30, 1994. These results were presented at the Fifth Annual NASA LA2ST Grant Review Meeting held at the Langley Research Center in July of 1994. The objective of the LA2ST Program is to conduct interdisciplinary graduate student research on the performance of next generation, lightweight aerospace alloys, composites, and thermal gradient structures in collaboration with NASA-Langley researchers. Specific technical objectives are presented for each research project. We generally aim to produce relevant data and basic understanding of material mechanical response, environmental/corrosion behavior, and microstructure; new monolithic and composite alloys; advanced processing methods; new solid and fluid mechanics analyses; measurement and modeling advances; and a pool of educated graduate students for aerospace technologies.

  11. Interdisciplinary and multilevel optimum design. [in aerospace structural engineering

    NASA Technical Reports Server (NTRS)

    Sobieszczanski-Sobieski, Jaroslaw; Haftka, Raphael T.

    1987-01-01

    Interactions among engineering disciplines and subsystems in engineering system design are surveyed and specific instances of such interactions are described. Examination of the interactions that a traditional design process in which the numerical values of major design variables are decided consecutively is likely to lead to a suboptimal design. Supporting numerical examples are a glider and a space antenna. Under an alternative approach introduced, the design and its sensitivity data from the subsystems and disciplines are generated concurrently and then made available to the system designer enabling him to modify the system design so as to improve its performance. Examples of a framework structure and an airliner wing illustrate that approach.

  12. Evaluation of Air Coupled Ultrasound for Composite Aerospace Structure

    NASA Astrophysics Data System (ADS)

    Tat, H.; Georgeson, G.; Bossi, R.

    2009-03-01

    Non-contact air coupled ultrasound suffers from the high acoustic impedance mismatch characteristics of air to solid interfaces. Advances in transducer technology, particularly MEMS, have improved the acoustic impedance match at the transmission stage and the signal to noise at the reception stage. Comparisons of through transmission (TTU) scanning of laminate and honeycomb test samples using conventional piezoelectric air coupled transducers, new MEMS air coupled transducers, and standard water coupled inspections have been performed to assess the capability. An additional issue for air coupled UT inspection is the need for a lean implementation for both manufacturing and in-service operations. Concepts and applications utilizing magnetic coupling of transducers have been developed that allows air coupled inspection operations in compact low cost configurations.

  13. Thick Films: Electronic Applications. (Latest citations from the Aerospace Database)

    NASA Technical Reports Server (NTRS)

    1996-01-01

    The bibliography contains citations concerning the design, development, fabrication, and evaluation of thick film electronic devices. Thick film solar cells, thick films for radiation conduction, deposition processes, conductive inks are among the topics discussed. Applications in military and civilian avionics are examined.

  14. Applications of aerospace technology in the electric power industry

    NASA Technical Reports Server (NTRS)

    Johnson, F. D.; Heins, C. F.

    1974-01-01

    Existing applications of NASA contributions to disciplines such as combustion engineering, mechanical engineering, materials science, quality assurance and computer control are outlined to illustrate how space technology is used in the electric power industry. Corporate strategies to acquire relevant space technology are described.

  15. Directionally Solidified Eutectic Ceramics for Multifunctional Aerospace Applications

    DTIC Science & Technology

    2013-01-01

    the challenges associated with ceramics are improving strength, toughness and creep resistance retaining the mechanical properties at elevated...applications: (1) the challenges associated with ceramics are improving strength, toughness and creep resistance retaining the mechanical properties at...mechanical properties of polyphase Al2Ti05 - A1203 system eutectic, which showed superior mechanical properties than the either constituent alone due

  16. Applications of aerospace technology in the environmental sciences

    NASA Technical Reports Server (NTRS)

    1972-01-01

    Detailed information is reported on the operations and accomplishments of the RTI Technology Application Team for the period October 11, 1971 to March 10, 1972. Mathematical models for prediction of pollutant formation during combustion are discussed along with generic areas of air pollution problems, which NASA technology offers a high potential for solving. Recommendations for future work are included.

  17. Fractional order PID controller for improvement of PMSM speed control in aerospace applications

    SciTech Connect

    Saraji, Ali Motalebi; Ghanbari, Mahmood

    2014-12-10

    Because of the benefits reduced size, cost and maintenance, noise, CO2 emissions and increased control flexibility and precision, to meet these expectations, electrical equipment increasingly utilize in modern aircraft systems and aerospace industry rather than conventional mechanic, hydraulic, and pneumatic power systems. Electric motor drives are capable of converting electrical power to drive actuators, pumps, compressors, and other subsystems at variable speeds. In the past decades, permanent magnet synchronous motor (PMSM) and brushless dc (BLDC) motor were investigated for aerospace applications such as aircraft actuators. In this paper, the fractional-order PID controller is used in the design of speed loop of PMSM speed control system. Having more parameters for tuning fractional order PID controller lead to good performance ratio to integer order. This good performance is shown by comparison fractional order PID controller with the conventional PI and tuned PID controller by Genetic algorithm in MATLAB soft wear.

  18. Fractional order PID controller for improvement of PMSM speed control in aerospace applications

    NASA Astrophysics Data System (ADS)

    Saraji, Ali Motalebi; Ghanbari, Mahmood

    2014-12-01

    Because of the benefits reduced size, cost and maintenance, noise, CO2 emissions and increased control flexibility and precision, to meet these expectations, electrical equipment increasingly utilize in modern aircraft systems and aerospace industry rather than conventional mechanic, hydraulic, and pneumatic power systems. Electric motor drives are capable of converting electrical power to drive actuators, pumps, compressors, and other subsystems at variable speeds. In the past decades, permanent magnet synchronous motor (PMSM) and brushless dc (BLDC) motor were investigated for aerospace applications such as aircraft actuators. In this paper, the fractional-order PID controller is used in the design of speed loop of PMSM speed control system. Having more parameters for tuning fractional order PID controller lead to good performance ratio to integer order. This good performance is shown by comparison fractional order PID controller with the conventional PI and tuned PID controller by Genetic algorithm in MATLAB soft wear.

  19. A Hydrogen Leak Detection System for Aerospace and Commercial Applications

    NASA Technical Reports Server (NTRS)

    Hunter, Gary W.; Makel, D. B.; Jansa, E. D.; Patterson, G.; Cova, P. J.; Liu, C. C.; Wu, Q. H.; Powers, W. T.

    1995-01-01

    Leaks on the space shuttle while on the launch pad have generated interest in hydrogen leak monitoring technology. Microfabricated hydrogen sensors are being fabricated at Case Western Reserve University (CWRU) and tested at NASA Lewis Research Center (LeRC). These sensors have been integrated into hardware and software designed by Aerojet. This complete system allows for multipoint leak monitoring designed to provide leak source and magnitude information in real time. The monitoring system processes data from the hydrogen sensors and presents the operator with a visual indication of the leak location and magnitude. Although the leak monitoring system was designed for hydrogen propulsion systems, the possible applications of this monitoring system are wide ranged. This system is in operation in an automotive application which requires high sensitivity to hydrogen.

  20. A hydrogen leak detection system for aerospace and commercial applications

    NASA Astrophysics Data System (ADS)

    Hunter, Gary W.; Makel, D. B.; Jansa, E. D.; Patterson, G.; Cova, P. J.; Liu, C. C.; Wu, Q. H.; Powers, W. T.

    1995-10-01

    Leaks on the space shuttle while on the launch pad have generated interest in hydrogen leak monitoring technology. Microfabricated hydrogen sensors are being fabricated at Case Western Reserve University (CWRU) and tested at NASA Lewis Research Center (LeRC). These sensors have been integrated into hardware and software designed by Aerojet. This complete system allows for multipoint leak monitoring designed to provide leak source and magnitude information in real time. The monitoring system processes data from the hydrogen sensors and presents the operator with a visual indication of the leak location and magnitude. Although the leak monitoring system was designed for hydrogen propulsion systems, the possible applications of this monitoring system are wide ranged. This system is in operation in an automotive application which requires high sensitivity to hydrogen.

  1. Manufacturing and NDE of Large Composite Aerospace Structures at MSFC

    NASA Technical Reports Server (NTRS)

    Whitaker, Ann

    2000-01-01

    NASA's vision for transportation to orbit calls for new vehicles built with new materials technology. The goals of this new launch system development are to improve safety, dramatically reduce cost to orbit, and improve vehicle turn around time. Planned Space Shuttle upgrades include new reusable liquid propellant boosters to replace the solid propellant boosters. These boosters are to have wings and return to the launch site for a horizontal landing on an airport runway. New single and two stages to orbit concepts are being investigated. To reduce weight and improve performance composite materials are proposed for fuel and oxidizer tanks, fuel feedlines, valve bodies, aerostructures, turbomachinery components. For large composite structures new methods of fabrication are being proposed and developed. Containment of cryogenic fuel or oxidizer requires emphases on composite material densification and chemical compatibility. Ceramic matrix and fiber composites for hot rotating turbomachinery have been developed with new fabrication processes. The new requirements on the materials for launcher components are requiring development of new manufacturing and inspection methods. This talk will examine new and proposed manufacturing methods to fabricate the revolutionary components. New NDE methods under consideration include alternative X-ray methods, X-ray laminagraphy, advanced CT, Thermography, new ultrasonic methods, and imbedded sensors. The sizes, complexity, use environment, and contamination restrictions will challenge the inspection process. In flight self-diagnosis and rapid depot inspection are also goals of the NDE development.

  2. Directionally Solidified Eutectic Ceramics for Multifunctional Aerospace Applications

    DTIC Science & Technology

    2009-06-01

    creep resistance retaining the mechanical properties at elevated temperatures and (2) to elucidate and demonstrate the multifunctional potential of...applications. We report progress on three different areas: 1. The mechanical properties of polyphase Al2TiO5 - Al2O3 system eutectic, which showed...superior mechanical properties than the either constituent alone due to the strong constraining effects provided by the coherent interfaces and

  3. Electron Beam Freeform Fabrication Technology Development for Aerospace Applications

    NASA Technical Reports Server (NTRS)

    Taminger, Karen M.

    2006-01-01

    NASA Langley has developed a the EBF(sup 3)process and currently has two EBF(sup 3) systems in house. EBF(sup 3) process offers potential cost reduction and fabrication of complex unitized structures out of metals. EBF(sup 3) has been successfully demonstrated on Al, Al-Li, Ti, and Ni alloys to date.

  4. Materials for defense/aerospace applications (NON-SV)

    SciTech Connect

    Ellis, A. R.

    2012-03-01

    Through this effort, Sandia and Lockheed Martin Aeronautics Company (LM Aero) sought to assess the feasibility of (1) applying special materials to a defense application; (2) developing a piezoelectric-based micro thermophotovoltaic (TPV) cell; and (3) building and delivering a prototype laboratory emission measurement system. This project supported the Stockpile Research & Development Program by contributing to the development of radio frequency (RF) MEMS- and optical MEMS-based components - such as switches, phase shifters, oscillators, and filters - with improved performance and reduced weight and size. Investigation of failure mechanisms and solutions helped to ensure that MEMS-based technology will meet performance requirements and long term reliability goals in the specified environments dictated by Lockheed Martin's commercial and defense applications. The objectives of this project were to (1) fabricate and test materials for military applications; (2) perform a feasibility study of a piezoelectric-based micro TPV cell; and (3) build and deliver a prototype laboratory emission measurement system. Sandia fabricated and tested properties of materials, studied options for manufacturing scale-up, and delivered a prototype IR Emissometer. LM Aero provided material requirements and designs. Both participated in the investigation of attachment methods and environmental effects on material performance, a feasibility study of piezoelectric TPV cells, an investigation and development of new approaches to implement the required material functionality, and analysis and validation of material performance physics, numerical models, and experimental metrology.

  5. Displacement Theories for In-Flight Deformed Shape Predictions of Aerospace Structures

    NASA Technical Reports Server (NTRS)

    Ko, William L.; Richards, W. L.; Tran, Van t.

    2007-01-01

    Displacement theories are developed for a variety of structures with the goal of providing real-time shape predictions for aerospace vehicles during flight. These theories are initially developed for a cantilever beam to predict the deformed shapes of the Helios flying wing. The main structural configuration of the Helios wing is a cantilever wing tubular spar subjected to bending, torsion, and combined bending and torsion loading. The displacement equations that are formulated are expressed in terms of strains measured at multiple sensing stations equally spaced on the surface of the wing spar. Displacement theories for other structures, such as tapered cantilever beams, two-point supported beams, wing boxes, and plates also are developed. The accuracy of the displacement theories is successfully validated by finite-element analysis and classical beam theory using input-strains generated by finite-element analysis. The displacement equations and associated strain-sensing system (such as fiber optic sensors) create a powerful means for in-flight deformation monitoring of aerospace structures. This method serves multiple purposes for structural shape sensing, loads monitoring, and structural health monitoring. Ultimately, the calculated displacement data can be visually displayed to the ground-based pilot or used as input to the control system to actively control the shape of structures during flight.

  6. Laser Materials Processing for NASA's Aerospace Structural Materials

    NASA Technical Reports Server (NTRS)

    Nagarathnam, Karthik; Hunyady, Thomas A.

    2001-01-01

    Lasers are useful for performing operations such as joining, machining, built-up freeform fabrication, and surface treatment. Due to the multifunctional nature of a single tool and the variety of materials that can be processed, these attributes are attractive in order to support long-term missions in space. However, current laser technology also has drawbacks for space-based applications. Specifically, size, power efficiency, lack of robustness, and problems processing highly reflective materials are all concerns. With the advent of recent breakthroughs in solidstate laser (e.g., diode-pumped lasers) and fiber optic technologies, the potential to perform multiple processing techniques in space has increased significantly. A review of the historical development of lasers from their infancy to the present will be used to show how these issues may be addressed. The review will also indicate where further development is necessary to realize a laser-based materials processing capability in space. The broad utility of laser beams in synthesizing various classes of engineering materials will be illustrated using state-of-the art processing maps for select lightweight alloys typically found on spacecraft. Both short- and long-term space missions will benefit from the development of a universal laser-based tool with low power consumption, improved process flexibility, compactness (e.g., miniaturization), robustness, and automation for maximum utility with a minimum of human interaction. The potential advantages of using lasers with suitable wavelength and beam properties for future space missions to the moon, Mars and beyond will be discussed. The laser processing experiments in the present report were performed using a diode pumped, pulsed/continuous wave Nd:YAG laser (50 W max average laser power), with a 1064 nm wavelength. The processed materials included Ti-6AI-4V, Al-2219 and Al-2090. For Phase I of this project, the laser process conditions were varied and optimized

  7. NASA-UVA Light Aerospace Alloy and Structures Technology program (LA2ST)

    NASA Technical Reports Server (NTRS)

    Starke, Edgar A., Jr.; Gangloff, Richard P.; Herakovich, Carl T.; Scully, John R.; Shiflet, Gary J.; Stoner, Glenn E.; Wert, John A.

    1995-01-01

    The objective of the LA2ST Program is to conduct interdisciplinary graduate student research on the performance of next generation, light-weight aerospace alloys, composites, and thermal gradient structures in collaboration with NASA-Langley researchers. The general aim is to produce relevant data and basic understanding of material mechanical response, environment/corrosion behavior, and microstructure; new monolithic and composite alloys; advanced processing methods; new solid and fluid mechanics analyses; measurement and modeling advances; and a pool of educated students for aerospace technologies. Specific technical objectives are presented for each of the following research projects: time-temperature dependent fracture in advanced wrought ingot metallurgy, and spray deposited aluminum alloys; cryogenic temperature effects on the deformation and fracture of Al-Li-Cu-In alloys; effects of aging and temperature on the ductile fracture of AA2095 and AA2195; mechanisms of localized corrosion in alloys 2090 and 2095; hydrogen interactions in aluminum-lithium alloys 2090 and selected model alloys; mechanisms of deformation and fracture in high strength titanium alloys (effects of temperature and hydrogen and effects of temperature and microstructure); evaluations of wide-panel aluminum alloy extrusions; Al-Si-Ge alloy development; effects of texture and precipitates on mechanical property anisotropy of Al-Cu-Mg-X alloys; damage evolution in polymeric composites; and environmental effects in fatigue life prediction - modeling crack propagation in light aerospace alloys.

  8. Combined Loads Test Fixture for Thermal-Structural Testing Aerospace Vehicle Panel Concepts

    NASA Technical Reports Server (NTRS)

    Fields, Roger A.; Richards, W. Lance; DeAngelis, Michael V.

    2004-01-01

    A structural test requirement of the National Aero-Space Plane (NASP) program has resulted in the design, fabrication, and implementation of a combined loads test fixture. Principal requirements for the fixture are testing a 4- by 4-ft hat-stiffened panel with combined axial (either tension or compression) and shear load at temperatures ranging from room temperature to 915 F, keeping the test panel stresses caused by the mechanical loads uniform, and thermal stresses caused by non-uniform panel temperatures minimized. The panel represents the side fuselage skin of an experimental aerospace vehicle, and was produced for the NASP program. A comprehensive mechanical loads test program using the new test fixture has been conducted on this panel from room temperature to 500 F. Measured data have been compared with finite-element analyses predictions, verifying that uniform load distributions were achieved by the fixture. The overall correlation of test data with analysis is excellent. The panel stress distributions and temperature distributions are very uniform and fulfill program requirements. This report provides details of an analytical and experimental validation of the combined loads test fixture. Because of its simple design, this unique test fixture can accommodate panels from a variety of aerospace vehicle designs.

  9. Solar and Thermal Energy Harvesting Textile Composites for Aerospace Applications

    DTIC Science & Technology

    2012-06-01

    ceramic that is typically used as a transparent electrode in or- ganic solar cells . This achievement is important for integration of PV functionality in...approaches to tuning the sensitivity bands of photodetectors, and improving light in-coupling in solar cells and pho- todetectors. Encouraged by these...PV) cells . Using this framework, we have designed and realized solar cell structures that do not use indium-tin oxide, a brittle and expensive

  10. Mechanically Strong Lightweight Materials for Aerospace Applications (x-aerogels)

    NASA Technical Reports Server (NTRS)

    Leventis, Nicholas

    2005-01-01

    The X-Aerogel is a new NASA-developed strong lightweight material made by reacting the mesoporous surfaces of 3-D networks of inorganic nanoparticles with polymeric crosslinkers. Since the relative amount of the crosslinker and the backbone are comparable, X-Aerogels can be viewed either as aerogels modified by templated accumulation of polymer on the skeletal nanoparticles, or as nanoporous polymers made by templated casting of polymeric precursors on a nanostructured framework. The most striking feature of X-Aerogels is that for a nominal 3-fold increase in density (still a ultralightweight material), the mechanical strength can be up to 300 times higher than the strength of the underlying native aerogel. Thus, X-Aerogels combine a multiple of the specific compressive strength of steel, with the thermal conductivity of styrofoam. XAerogels have been demonstrated with several polymers such as polyurethanes/polyureas, epoxies and polyolefins, while crosslinking of approximately 35 different oxide aerogels yields a wide variety of dimensionally stable, porous lightweight materials with interesting structural, magnetic and optical properties. X-Aerogels are evaluated for cryogenic rocket fuel storage tanks and for Advanced EVA suits, where they will play the dual role of the thermal insulator/structural material. Along the same lines, major impact is also expected by the use of X-Aerogels in structural components/thermal protection for small satellites, spacecrafts, planetary vehicles and habitats.

  11. Design and analysis of aerospace structures at elevated temperatures. [aircraft, missiles, and space platforms

    NASA Technical Reports Server (NTRS)

    Chang, C. I.

    1989-01-01

    An account is given of approaches that have emerged as useful in the incorporation of thermal loading considerations into advanced composite materials-based aerospace structural design practices. Sources of structural heating encompass not only propulsion system heat and aerodynamic surface heating at supersonic speeds, but the growing possibility of intense thermal fluxes from directed-energy weapons. The composite materials in question range from intrinsically nonheat-resistant polymer matrix systems to metal-matrix composites, and increasingly to such ceramic-matrix composites as carbon/carbon, which are explicitly intended for elevated temperature operation.

  12. Applications of fiber optic sensors in the aerospace and marine industries

    NASA Astrophysics Data System (ADS)

    Culshaw, Brian

    Current and potential aerospace and marine applications of fiber-optic device technology are surveyed and illustrated with diagrams, drawings, and photographs. Consideration is given to fiber-optic gyros for guidance and navigation; temperature, pressure, displacement, smoke-detection, fuel-level and fuel-flow, vibration, and acceleration sensors for flight-control systems; sensors for turbine-engine monitoring and testing; and embedded-fiber testing and process-monitoring methods for advanced composite materials. The specifically marine applications discussed are arrays of hydrophones and magnetometers based on fibers with acoustic and magnetic coatings, respectively.

  13. Multi-agent systems design for aerospace applications

    NASA Astrophysics Data System (ADS)

    Waslander, Steven L.

    2007-12-01

    Engineering systems with independent decision makers are becoming increasingly prevalent and present many challenges in coordinating actions to achieve systems goals. In particular, this work investigates the applications of air traffic flow control and autonomous vehicles as motivation to define algorithms that allow agents to agree to safe, efficient and equitable solutions in a distributed manner. To ensure system requirements will be satisfied in practice, each method is evaluated for a specific model of agent behavior, be it cooperative or non-cooperative. The air traffic flow control problem is investigated from the point of view of the airlines, whose costs are directly affected by resource allocation decisions made by the Federal Aviation Administration in order to mitigate traffic disruptions caused by weather. Airlines are first modeled as cooperative, and a distributed algorithm is presented with various global cost metrics which balance efficient and equitable use of resources differently. Next, a competitive airline model is assumed and two market mechanisms are developed for allocating contested airspace resources. The resource market mechanism provides a solution for which convergence to an efficient solution can be guaranteed, and each airline will improve on the solution that would occur without its inclusion in the decision process. A lump-sum market is then introduced as an alternative mechanism, for which efficiency loss bounds exist if airlines attempt to manipulate prices. Initial convergence results for lump-sum markets are presented for simplified problems with a single resource. To validate these algorithms, two air traffic flow models are developed which extend previous techniques, the first a convenient convex model made possible by assuming constant velocity flow, and the second a more complex flow model with full inflow, velocity and rerouting control. Autonomous vehicle teams are envisaged for many applications including mobile sensing

  14. Thermally stable, low dielectric polyquinolines for aerospace and electronics applications

    NASA Technical Reports Server (NTRS)

    Hendricks, Neil H.; Marrocco, Matthew L.; Stoakley, Diane M.; St. Clair, Anne K.

    1990-01-01

    Four new high molecular weight, linear chain polyquinolines have been synthesized and fabricated into high quality free standing films. These polymers are characterized by moderate to high glass transition temperatures, excellent thermal and thermooxidative stability, extremely low dielectric constants and good planarizing characteristics. The polymers absorb very low quantities of moisture. As a consequence, the dielectric constant of one new polyquinoline has been shown to be quite insensitive to exposure to warm/wet conditions. Isothermal aging of one new derivative in air has been carried out at elevated temperatures (250 C to 345 C). The results demonstrate truly outstanding thermooxidative stability. Additional characterizations include molecular weight determinations, solubilities and film-forming characteristics, density measurements, and UV-Vis spectroscopy. The data acquired to date suggest that the polymers may find use as refractive films and coatings and as interlevel planarizers in microelectronics applications.

  15. A fiber-optic current sensor for aerospace applications

    NASA Technical Reports Server (NTRS)

    Patterson, Richard L.; Rose, A. H.; Tang, D.; Day, G. W.

    1990-01-01

    A robust, accurate, broad-band, alternating current sensor using fiber optics is being developed for space applications at power frequencies as high as 20 kHz. It can also be used in low and high voltage 60 Hz terrestrial power systems and in 400 Hz aircraft systems. It is intrinsically electromagnetic interference (EMI) immune and has the added benefit of excellent isolation. The sensor uses the Faraday effect in optical fiber and standard polarimetric measurements to sense electrical current. The primary component of the sensor is a specially treated coil of single-mode optical fiber, through which the current carrying conductor passes. Improved precision is accomplished by temperature compensation by means of signals from a novel fiber-optic temperature sensor embedded in the sensing head. The technology contained in the sensor is examined and the results of precision tests conducted at various temperatures within the wide operating range are given. The results of early EMI tests are also given.

  16. A fiber-optic current sensor for aerospace applications

    NASA Technical Reports Server (NTRS)

    Patterson, Richard L.; Rose, A. H.; Tang, D.; Day, G. W.

    1990-01-01

    A robust, accurate, broadband, alternating current sensor using fiber optics is being developed for space applications at power frequencies as high as 20 kHz. It can also be used in low- and high-voltage 60-Hz terrestrial power systems and in 400-Hz aircraft systems. It is intrinsically EMI (electromagnetic interference) immune and has the added benefit of excellent isolation. The sensor uses the Faraday effect in optical fiber and standard polarimetric measurements to sense electrical current. The primary component of the sensor is a specially treated coil of single-mode optical fiber, through which the current carrying conductor passes. Improved precision is accomplished by temperature compensation by means of signals from a fiber-optic temperature sensor embedded in the sensing head. The authors report on the technology contained in the sensor and also relate the results of precision tests conducted at various temperatures within the wide operating range. The results of early EMI tests are shown.

  17. A fiber-optic current sensor for aerospace applications

    NASA Technical Reports Server (NTRS)

    Patterson, Richard L.; Rose, A. H.; Tang, D.; Day, G. W.

    1990-01-01

    A robust, accurate, broadband, alternating current sensor using fiber optics is being developed for space applications at power frequencies as high as 20 kHz. It can also be used in low and high voltage 60-Hz terrestrial power systems and in 400-Hz aircraft systems. It is intrinsically electromagnetic interference (EMI) immune and has the added benefit of excellent isolation. The sensor uses the Faraday effect in optical fiber and standard polarimetric measurements to sense electrical current. The primary component of the sensor is a specially treated coil of single-mode optical fiber, through which the current carrying conductor passes. Improved precision is accomplished by temperature compensation by means of signals from a novel fiber-optic temperature sensor embedded in the sensing head. The technology used in the sensor is examined and the results of precision tests conducted at various temperatures within the wide operating range are given. The results of early EMI tests are also given.

  18. Some contributions to energetics by the Lewis Research Center and a review of their potential non-aerospace applications

    NASA Technical Reports Server (NTRS)

    Graham, R. W.; Gutstein, M. U.

    1972-01-01

    The primary technology areas are aerospace propulsion, power and materials. As examples in these technologies, the programs in the fields of cryogenics and liquid metals are reviewed and potential non-aerospace applications for the results of these programs are discussed. These include such possibilities as: hydrogen as a non-polluting industrial fuel; more efficient central power stations; and powerplants for advanced ground transportation.

  19. Mechanical Characterization of Composites and Foams for Aerospace Applications

    NASA Technical Reports Server (NTRS)

    Veazie, D. R.; Glinsey, C.; Webb, M. M.; Norman, M.; Meador, Michael A. (Technical Monitor)

    2000-01-01

    Experimental studies to investigate the mechanical properties of ultra-lightweight polyimide foams for space applications, compression after impact (CAI) properties for low velocity impact of sandwich composites, and aspen fiber/polypropylene composites containing an interface adhesive additive, Maleic Anhydride Grafted Polypropylene (MAPP), were performed at Clark Atlanta University. Tensile, compression, flexural, and shear modulus tests were performed on TEEK foams categorized by their densities and relative cost according to ASTM specifications. Results showed that the mechanical properties of the foams increased as a function of higher price and increasing density. The CAI properties of Nomex/phenolic honeycomb core, fiberglass/epoxy facesheet sandwich composites for two damage arrangements were compared using different levels of impact energy ranging from 0 - 452 Joules. Impact on the thin side showed slightly more retention of CAI strength at low impact levels, whereas higher residual compressive strength was observed from impact on the thick side at higher impact levels. The aspen fiber/polypropylene composites studied are composed of various percentages (by weight) of aspen fiber and polypropylene ranging from 30%-60% and 40%-100%, respectively. Results showed that the MAPP increases tensile and flexural strength, while having no significant influence on tensile and flexural modulus.

  20. Wide Range Neutron Flux Measuring Channel for Aerospace Application

    NASA Astrophysics Data System (ADS)

    Cibils, R. M.; Busto, A.; Gonella, J. L.; Martinez, R.; Chielens, A. J.; Otero, J. M.; Nuñez, M.; Tropea, S. E.

    2008-01-01

    The use of classical techniques for neutron flux measurements in nuclear reactors involves the switching between several detection chains as the power grows up to 10 decades. In space applications where mass and size constraints are of key significance, such volume of hardware represents a clear disadvantage. Instead of requiring different instruments for each reactor operating range (start-up, ramping-up, and nominal power), a single instrument chain should be desirable. A Wide Range Neutron Detector (WRND) system, combining a classic pulse Counting Channel with a Campbell's theorem based Fluctuation Channel can be implemented for the monitoring and control of a space nuclear reactor. Such an instrument will allow for a reduction in the complexity of space-based nuclear instrumentation and control systems. In this presentation we will discuss the criteria and tradeoffs involved in the development of such a system. We will focus particularly on the characteristics of the System On Chip (SOC) and the DSP board used to implement this instrument.

  1. Microfabricated Chemical Sensors for Aerospace Fire Detection Applications

    NASA Technical Reports Server (NTRS)

    Hunter, Gary W.; Neudeck, Philip G.; Fralick, Gustave; Thomas, Valarie; Makel, D.; Liu, C. C.; Ward, B.; Wu, Q. H.

    2001-01-01

    The detection of fires on-board commercial aircraft is extremely important for safety reasons. Although dependable fire detection equipment presently exists within the cabin, detection of fire within the cargo hold has been less reliable and susceptible to false alarms. A second, independent method of fire detection to complement the conventional smoke detection techniques, such as the measurement of chemical species indicative of a fire, will help reduce false alarms and improve aircraft safety. Although many chemical species are indicative of a fire, two species of particular interest are CO and CO2. This paper discusses microfabricated chemical sensor development tailored to meet the needs of fire safety applications. This development is based on progress in three types of technology: 1) Micromachining and microfabrication (Microsystem) technology to fabricate miniaturized sensors. 2) The use of nanocrystalline materials to develop sensors with improved stability combined with higher sensitivity. 3) The development of high temperature semiconductors, especially silicon carbide. The individual sensor being developed and their level of maturity will be presented.

  2. Mechanical Behavior of Advanced Materials for Aerospace Applications

    NASA Technical Reports Server (NTRS)

    Telesman, Ignancy (Technical Monitor); Kantzos, Peter; Shannon, Brian

    2003-01-01

    The purpose of this study was to determine whether High Cycle Fatigue (HCF) loading has any deleterious synergistic effect on life when combined with the typical Low Cycle Fatigue (LCF) loading present in engine disks. This interaction is particularly important in the rim region of blisk applications, where fatigue initiations from vibratory stresses (HCF) may be propagated to the disk by LCF. The primary effort in this study was focused on determining and documenting initiation sites and damage mechanisms. Under LCF loading conditions the failures were predominantly surface initiated, while HCF loading favored internal initiations. Deleterious HCF/LCF interactions would always result in a transition from internal to surface initiations. The results indicated that under the relative stress conditions evaluated there was no interaction between HCF and LCF. In FY99 this effort was extended to investigate several other loading conditions (R-ratio effects) as well as interactions between LCF and two-hour tensile dwells. The results will be published as a NASA Technical Memorandum.

  3. Low cost split stirling cryogenic cooler for aerospace applications

    NASA Astrophysics Data System (ADS)

    Veprik, Alexander; Zechtzer, Semeon; Pundak, Nachman; Riabzev, Sergey; Kirckconnel, C.; Freeman, Jeremy

    2012-06-01

    Cryogenic coolers are used in association with sensitive electronics and sensors for military, commercial or scientific space payloads. The general requirements are high reliability and power efficiency, low vibration export and ability to survive launch vibration extremes and long-term exposure to space radiation. A long standing paradigm of using exclusively space heritage derivatives of legendary "Oxford" cryocoolers featuring linear actuators, flexural bearings, contactless seals and active vibration cancellation is so far the best known practice aiming at delivering high reliability components for the critical and usually expensive space missions. The recent tendency of developing mini and micro satellites for the budget constrained missions has spurred attempts to adapt leading-edge tactical cryogenic coolers to meet the space requirements. The authors are disclosing theoretical and practical aspects of a collaborative effort on developing a space qualified cryogenic refrigerator based on the Ricor model K527 tactical cooler and Iris Technology radiation hardened, low cost cryocooler electronics. The initially targeted applications are cost-sensitive flight experiments, but should the results show promise, some long-life "traditional" cryocooler missions may well be satisfied by this approach.

  4. Wide Range Neutron Flux Measuring Channel for Aerospace Application

    SciTech Connect

    Cibils, R. M.; Busto, A.; Gonella, J. L.; Martinez, R.; Chielens, A. J.; Otero, J. M.; Nunez, M.; Tropea, S. E.

    2008-01-21

    The use of classical techniques for neutron flux measurements in nuclear reactors involves the switching between several detection chains as the power grows up to 10 decades. In space applications where mass and size constraints are of key significance, such volume of hardware represents a clear disadvantage. Instead of requiring different instruments for each reactor operating range (start-up, ramping-up, and nominal power), a single instrument chain should be desirable. A Wide Range Neutron Detector (WRND) system, combining a classic pulse Counting Channel with a Campbell's theorem based Fluctuation Channel can be implemented for the monitoring and control of a space nuclear reactor. Such an instrument will allow for a reduction in the complexity of space-based nuclear instrumentation and control systems. In this presentation we will discuss the criteria and tradeoffs involved in the development of such a system. We will focus particularly on the characteristics of the System On Chip (SOC) and the DSP board used to implement this instrument.

  5. NASA biomedical applications team. Applications of aerospace technology in biology and medicine

    NASA Technical Reports Server (NTRS)

    Rouse, D. J.; Beadles, R.; Beall, H. C.; Brown, J. N., Jr.; Clingman, W. H.; Courtney, M. W.; Mccartney, M.; Scearce, R. W.; Wilson, B.

    1979-01-01

    The use of a bipolar donor-recipient model of medical technology transfer is presented. That methodology is designed to: (1) identify medical problems and aerospace technology that in combination constitute opportunities for successful medical products; (2) obtain the early participation of industry in the transfer process; and (3) obtain acceptance by the medical community of new medical products based on aerospace technology. Problem descriptions and activity reports and the results of a market study on the tissue freezing device are presented.

  6. Cognitive engineering in aerospace application: Pilot interaction with cockpit automation

    NASA Technical Reports Server (NTRS)

    Sarter, Nadine R.; Woods, David D.

    1993-01-01

    Because of recent incidents involving glass-cockpit aircraft, there is growing concern with cockpit automation and its potential effects on pilot performance. However, little is known about the nature and causes of problems that arise in pilot-automation interaction. The results of two studies that provide converging, complementary data on pilots' difficulties with understanding and operating one of the core systems of cockpit automation, the Flight Management System (FMS) is reported. A survey asking pilots to describe specific incidents with the FMS and observations of pilots undergoing transition training to a glass cockpit aircraft served as vehicles to gather a corpus on the nature and variety of FMS-related problems. The results of both studies indicate that pilots become proficient in standard FMS operations through ground training and subsequent line experience. But even with considerable line experience, they still have difficulties tracking FMS status and behavior in certain flight contexts, and they show gaps in their understanding of the functional structure of the system. The results suggest that design-related factors such as opaque interfaces contribute to these difficulties which can affect pilots' situation awareness. The results of this research are relevant for both the design of cockpit automation and the development of training curricula specifically tailored to the needs of glass cockpits.

  7. Advances in Ceramic Matrix Composite Blade Damping Characteristics for Aerospace Turbomachinery Applications

    NASA Technical Reports Server (NTRS)

    Min, James B.; Harris, Donald L.; Ting, J. M.

    2011-01-01

    For advanced aerospace propulsion systems, development of ceramic matrix composite integrally-bladed turbine disk technology is attractive for a number of reasons. The high strength-to-weight ratio of ceramic composites helps to reduce engine weight and the one-piece construction of a blisk will result in fewer parts count, which should translate into reduced operational costs. One shortcoming with blisk construction, however, is that blisks may be prone to high cycle fatigue due to their structural response to high vibration environments. Use of ceramic composites is expected to provide some internal damping to reduce the vibratory stresses encountered due to unsteady flow loads through the bladed turbine regions. A goal of our research was to characterize the vibration viscous damping behavior of C/SiC composites. The vibration damping properties were measured and calculated. Damping appeared to decrease with an increase in the natural frequency. While the critical damping amount of approximately 2% is required for typical aerospace turbomachinery engines, the C/SiC damping at high frequencies was less than 0.2% from our study. The advanced high-performance aerospace propulsion systems almost certainly will require even more damping than what current vehicles require. A purpose of this paper is to review some work on C/SiC vibration damping by the authors for the NASA CMC turbine blisk development program and address an importance of the further investigation of the blade vibration damping characteristics on candidate CMC materials for the NASA s advanced aerospace turbomachinery engine systems.

  8. An Integrated MEMS Sensor Cluster System for Aerospace Applications

    NASA Technical Reports Server (NTRS)

    Kahng, Seun; Scott, Michael A.; Beeler, George B.; Bartlett, James E.; Collins, Richard S.

    2000-01-01

    Efforts to reduce viscous drag on airfoils could results in a considerable saving for the operation of flight vehicles including those of space transportation. This reduction of viscous drag effort requires measurement and active control of boundary layer flow property on an airfoil. Measurement of viscous drag of the boundary layer flow over an airfoil with minimal flow disturbance is achievable with newly developed MEMS sensor clusters. These sensor clusters provide information that can be used to actively control actuators to obtain desired flow properties or design a vehicle to satisfy particular boundary layer flow criteria. A series of MEMS sensor clusters has been developed with a data acquisition and control module for local measurements of shear stress, pressure, and temperature on an airfoil. The sensor cluster consists of two shear stress sensors, two pressure sensors, and two temperature sensors on a surface area of 1.24 mm x 1.86 mm. Each sensor is 300 microns square and is placed on a flexible polyimide sheet. The shear stress sensor is a polysilicon hot-film resistor, which is insulated by a vacuum cavity of 200 x 200 x 2 microns. The pressure sensors are silicon piezoresistive type, and the temperature sensors are also hot film polysilicon resistors. The total size of the cluster including sensors and electrical leads is 1 Omm x 1 Omm x 0.1 mm. A typical sensitivity of shear stress sensor is 150 mV/Pascal, the pressure sensors are an absolute type with a measurement range from 9 to 36 psia with 0.8mV/V/psi sensitivity, and the temperature sensors have a measurement resolution of 0.1 degree C. The sensor clusters are interfaced to a data acquisition and control module that consists of two custom ASICs (Application Specific Integrated Circuits) and a micro-controller. The data acquisition and control module transfers data to a host PC that configures and controls a total of three sensor clusters. Functionality of the entire system has been tested in

  9. Practical theories for service life prediction of critical aerospace structural components

    NASA Technical Reports Server (NTRS)

    Ko, William L.; Monaghan, Richard C.; Jackson, Raymond H.

    1992-01-01

    A new second-order theory was developed for predicting the service lives of aerospace structural components. The predictions based on this new theory were compared with those based on the Ko first-order theory and the classical theory of service life predictions. The new theory gives very accurate service life predictions. An equivalent constant-amplitude stress cycle method was proposed for representing the random load spectrum for crack growth calculations. This method predicts the most conservative service life. The proposed use of minimum detectable crack size, instead of proof load established crack size as an initial crack size for crack growth calculations, could give a more realistic service life.

  10. NDE of Fiber Reinforced Foam Composite Structures for Future Aerospace Vehicles

    NASA Technical Reports Server (NTRS)

    Walker, james; Roth, Don; Hopkins, Dale

    2010-01-01

    This slide presentation reviews the complexities of non-destructive evaluation (NDE) of fiber reinforced foam composite structures to be used for aerospace vehicles in the future.Various views of fiber reinforced foam materials are shown and described. Conventional methods of NDE for composites are reviewed such as Micro-computed X-Ray Tomography, Thermography, Shearography, and Phased Array Ultrasonics (PAUT). These meth0ods appear to work well on the face sheet and face sheet ot core bond, they do not provide adequate coverage for the webs. There is a need for additional methods that will examine the webs and web to foam core bond.

  11. Vocabulary of aerospace safety terms pertaining to cryogenic safety, fires, explosions, and structure failure

    NASA Technical Reports Server (NTRS)

    Pelouch, J. J., Jr.; Mandel, G.; Ordin, P. M.

    1976-01-01

    This vocabulary listing characterizes the contents of over 10,000 documents of the NASA Aerospace Safety Research and Data Institute's (ASRDI) safety engineering collection. The ASRDI collection is now one of the series accessible on the NASA RECON data base. There are approximately 6,300 postable terms that describe literature in the areas of cryogenic fluid safety, specifically hydrogen, oxygen, liquified natural gas; fire and explosion technology; and the mechanics of structural failure. To facilitate the proper selection of information nonpostable, related and array terms have been included in this listing.

  12. The development of nickel-metal hydride technology for use in aerospace applications

    NASA Astrophysics Data System (ADS)

    Rampel, Guy; Johnson, Herschel; dell, Dan; Wu, Tony; Puglisi, Vince

    1992-02-01

    The nickel metal hydride technology for battery application is relatively immature even though this technology was made widely known by Philips' scientists as long ago as 1970. Recently, because of the international environmental regulatory pressures being placed on cadmium in the workplace and in disposal practices, battery companies have initiated extensive development programs to make this technology a viable commercial operation. These hydrides do not pose a toxilogical threat as does cadmium. Also, they provide a higher energy density and specific energy when compared to the other nickel based battery technologies. For these reasons, the nickel metal hydride electrochemisty is being evaluated as the next power source for varied applications such as laptop computers, cellular telephones, electric vehicles, and satellites. A parallel development effort is under way to look at aerospace applications for nickel metal hydride cells. This effort is focused on life testing of small wound cells of the commercial type to validate design options and development of prismatic design cells for aerospace applications.

  13. The development of nickel-metal hydride technology for use in aerospace applications

    NASA Technical Reports Server (NTRS)

    Rampel, Guy; Johnson, Herschel; Dell, Dan; Wu, Tony; Puglisi, Vince

    1992-01-01

    The nickel metal hydride technology for battery application is relatively immature even though this technology was made widely known by Philips' scientists as long ago as 1970. Recently, because of the international environmental regulatory pressures being placed on cadmium in the workplace and in disposal practices, battery companies have initiated extensive development programs to make this technology a viable commercial operation. These hydrides do not pose a toxilogical threat as does cadmium. Also, they provide a higher energy density and specific energy when compared to the other nickel based battery technologies. For these reasons, the nickel metal hydride electrochemisty is being evaluated as the next power source for varied applications such as laptop computers, cellular telephones, electric vehicles, and satellites. A parallel development effort is under way to look at aerospace applications for nickel metal hydride cells. This effort is focused on life testing of small wound cells of the commercial type to validate design options and development of prismatic design cells for aerospace applications.

  14. Friction Stir Welding of Metal Matrix Composites for use in aerospace structures

    NASA Astrophysics Data System (ADS)

    Prater, Tracie

    2014-01-01

    Friction Stir Welding (FSW) is a relatively nascent solid state joining technique developed at The Welding Institute (TWI) in 1991. The process was first used at NASA to weld the super lightweight external tank for the Space Shuttle. Today FSW is used to join structural components of the Delta IV, Atlas V, and Falcon IX rockets as well as the Orion Crew Exploration Vehicle. A current focus of FSW research is to extend the process to new materials which are difficult to weld using conventional fusion techniques. Metal Matrix Composites (MMCs) consist of a metal alloy reinforced with ceramics and have a very high strength to weight ratio, a property which makes them attractive for use in aerospace and defense applications. MMCs have found use in the space shuttle orbiter's structural tubing, the Hubble Space Telescope's antenna mast, control surfaces and propulsion systems for aircraft, and tank armors. The size of MMC components is severely limited by difficulties encountered in joining these materials using fusion welding. Melting of the material results in formation of an undesirable phase (formed when molten Aluminum reacts with the reinforcement) which leaves a strength depleted region along the joint line. Since FSW occurs below the melting point of the workpiece material, this deleterious phase is absent in FSW-ed MMC joints. FSW of MMCs is, however, plagued by rapid wear of the welding tool, a consequence of the large discrepancy in hardness between the steel tool and the reinforcement material. This work characterizes the effect of process parameters (spindle speed, traverse rate, and length of joint) on the wear process. Based on the results of these experiments, a phenomenological model of the wear process was constructed based on the rotating plug model for FSW. The effectiveness of harder tool materials (such as Tungsten Carbide, high speed steel, and tools with diamond coatings) to combat abrasive wear is explored. In-process force, torque, and

  15. California four cities program, 1971 - 1973. [aerospace-to-urban technology application

    NASA Technical Reports Server (NTRS)

    Macomber, H. L.; Wilson, J. H.

    1974-01-01

    A pilot project in aerospace-to-urban technology application is reported. Companies assigned senior engineering professionals to serve as Science and Technology Advisors to participating city governments. Technical support was provided by the companies and JPL. The cities, Anaheim, Fresno, Pasadena, and San Hose, California, provided the working environment and general service support. Each city/company team developed and carried out one or more technical or management pilot projects together with a number of less formalized technology efforts and studies. An account and evaluation is provided of the initial two-year phase of the program.

  16. Water recovery and solid waste processing for aerospace and domestic applications. Volume 1: Final report

    NASA Technical Reports Server (NTRS)

    Murray, R. W.

    1973-01-01

    A comprehensive study of advanced water recovery and solid waste processing techniques employed in both aerospace and domestic or commercial applications is reported. A systems approach was used to synthesize a prototype system design of an advanced water treatment/waste processing system. Household water use characteristics were studied and modified through the use of low water use devices and a limited amount of water reuse. This modified household system was then used as a baseline system for development of several water treatment waste processing systems employing advanced techniques. A hybrid of these systems was next developed and a preliminary design was generated to define system and hardware functions.

  17. Morphology-Dependent Resonances and Their Applications to Sensing in Aerospace Environments

    NASA Technical Reports Server (NTRS)

    Adamovsky, G.; Otugen, M.V.

    2009-01-01

    This paper reviews recent developments in Morphology-Dependent Resonance (MDR)-based sensors for aerospace applications. The sensor concept is based on the detection of small shifts of optical resonances (also called the whispering gallery modes or WGM) of dielectric spheres caused by external effects. Recent developments in MRD-based micro-optical sensors for temperature, force, pressure, and concentration are discussed. In addition to the experimental configurations used in each type of prototype sensor, a brief overview is also given for analytical approaches to describe the sensor principle.

  18. Theory to test comparisons for selected aerospace multishell structures and their interfaces under thermomechanical loadings

    NASA Technical Reports Server (NTRS)

    Ferdie, R. D.; Ligocki, J. E.; England, D. H.

    1974-01-01

    Guidelines for structural shell analyses were obtained on the basis of theory-to-test comparisons made on two large-scale aerospace structures subject to thermomechanical loads. The first structural test was the cylindrical aluminum skin-stringer-ring construction of the S-IC forward skirt and S-II interstage. The second structural test included the truncated, cone-shaped, bonded honeycomb sandwich shell of the Spacecraft Lunar Module Adapter; the cylindrical bonded aluminum honeycomb sandwich construction of the Instrument Unit; and the skin-stringer construction with rings and intercostals of the S-IVB forward skirt. Analyses were made for loadings simulating the flight environment. Elementary shear lag theory was superimposed on shell analysis for interface junctions between stages to obtain favorable theory-to-test stress comparisons.

  19. Smart Aerospace eCommerce: Using Intelligent Agents in a NASA Mission Services Ordering Application

    NASA Technical Reports Server (NTRS)

    Moleski, Walt; Luczak, Ed; Morris, Kim; Clayton, Bill; Scherf, Patricia; Obenschain, Arthur F. (Technical Monitor)

    2002-01-01

    This paper describes how intelligent agent technology was successfully prototyped and then deployed in a smart eCommerce application for NASA. An intelligent software agent called the Intelligent Service Validation Agent (ISVA) was added to an existing web-based ordering application to validate complex orders for spacecraft mission services. This integration of intelligent agent technology with conventional web technology satisfies an immediate NASA need to reduce manual order processing costs. The ISVA agent checks orders for completeness, consistency, and correctness, and notifies users of detected problems. ISVA uses NASA business rules and a knowledge base of NASA services, and is implemented using the Java Expert System Shell (Jess), a fast rule-based inference engine. The paper discusses the design of the agent and knowledge base, and the prototyping and deployment approach. It also discusses future directions and other applications, and discusses lessons-learned that may help other projects make their aerospace eCommerce applications smarter.

  20. New Method Developed To Purify Single Wall Carbon Nanotubes for Aerospace Applications

    NASA Technical Reports Server (NTRS)

    Lebron, Marisabel; Meador, Michael A.

    2003-01-01

    Single wall carbon nanotubes have attracted considerable attention because of their remarkable mechanical properties and electrical and thermal conductivities. Use of these materials as primary or secondary reinforcements in polymers or ceramics could lead to new materials with significantly enhanced mechanical strength and electrical and thermal conductivity. Use of carbon-nanotube-reinforced materials in aerospace components will enable substantial reductions in component weight and improvements in durability and safety. Potential applications for single wall carbon nanotubes include lightweight components for vehicle structures and propulsion systems, fuel cell components (bipolar plates and electrodes) and battery electrodes, and ultra-lightweight materials for use in solar sails. A major barrier to the successful use of carbon nanotubes in these components is the need for methods to economically produce pure carbon nanotubes in large enough quantities to not only evaluate their suitability for certain applications but also produce actual components. Most carbon nanotube synthesis methods, including the HiPCO (high pressure carbon monoxide) method developed by Smalley and others, employ metal catalysts that remain trapped in the final product. These catalyst impurities can affect nanotube properties and accelerate their decomposition. The development of techniques to remove most, if not all, of these impurities is essential to their successful use in practical applications. A new method has been developed at the NASA Glenn Research Center to purify gram-scale quantities of single wall carbon nanotubes. This method, a modification of a gas phase purification technique previously reported by Smalley and others, uses a combination of high-temperature oxidations and repeated extractions with nitric and hydrochloric acid. This improved procedure significantly reduces the amount of impurities (catalyst and nonnanotube forms of carbon) within the nanotubes, increasing

  1. NASA-UVA Light Aerospace Alloy and Structures Technology Program (LA2ST)

    NASA Technical Reports Server (NTRS)

    Gangloff, Richard P.; Scully, John R.; Stoner, Glenn E.; Thornton, Earl A.; Wawner, Franklin E., Jr.; Wert, John A.

    1993-01-01

    The NASA-UVA Light Aerospace Alloy and Structures Technology (LA2ST) Program continues a high level of activity. Progress achieved between 1 Jan. and 30 Jun. 1993 is reported. The objective of the LA2ST Program is to conduct interdisciplinary graduate student research on the performance of next generation, light weight aerospace alloys, composites, and thermal gradient structures in collaboration with NASA-Langley researchers. The following projects are addressed: environmental fatigue of Al-Li-Cu alloys; mechanisms of localized corrosion and environmental fracture in Al-Cu-Li-Mg-Ag alloy X2095 and compositional variations; the effect of zinc additions on the precipitation and stress corrosion cracking behavior of alloy 8090; hydrogen interactions with Al-Li-Cu alloy 2090 and model alloys; metastable pitting of aluminum alloys; cryogenic fracture toughness of Al-Cu-Li + In alloys; the fracture toughness of Weldalite (TM); elevated temperature cracking of advanced I/M aluminum alloys; response of Ti-1100/SCS-6 composites to thermal exposure; superplastic forming of Weldalite (TM); research to incorporate environmental effects into fracture mechanics fatigue life prediction codes such as NASA FLAGRO; and thermoviscoplastic behavior.

  2. Thermostructural applications of heat pipes for cooling leading edges of high-speed aerospace vehicles

    NASA Technical Reports Server (NTRS)

    Camarda, Charles J.; Glass, David E.

    1992-01-01

    Heat pipes have been considered for use on wing leading edge for over 20 years. Early concepts envisioned metal heat pipes cooling a metallic leading edge. Several superalloy/sodium heat pipes were fabricated and successfully tested for wing leading edge cooling. Results of radiant heat and aerothermal testing indicate the feasibility of using heat pipes to cool the stagnation region of shuttle-type space transportation systems. The test model withstood a total seven radiant heating tests, eight aerothermal tests, and twenty-seven supplemental radiant heating tests. Cold-wall heating rates ranged from 21 to 57 Btu/sq ft-s and maximum operating temperatures ranged from 1090 to 1520 F. Follow-on studies investigated the application of heat pipes to cool the stagnation regions of single-stage-to-orbit and advanced shuttle vehicles. Results of those studies indicate that a 'D-shaped' structural design can reduce the mass of the heat-pipe concept by over 44 percent compared to a circular heat-pipe geometry. Simple analytical models for heat-pipe startup from the frozen state (working fluid initially frozen) were adequate to approximate transient, startup, and steady-state heat-pipe performance. Improvement in analysis methods has resulted in the development of a finite-element analysis technique to predict heat-pipe startup from the frozen state. However, current requirements of light-weight design and reliability suggest that metallic heat pipes embedded in a refractory composite material should be used. This concept is the concept presently being evaluated for NASP. A refractory-composite/heat-pipe-cooled wing leading edge is currently being considered for the National Aero-Space Plane (NASP). This concept uses high-temperature refractory-metal/lithium heat pipes embedded within a refractory-composite structure and is significantly lighter than an actively cooled wing leading edge because it eliminates the need for active cooling during ascent and descent. Since the

  3. The new low nitrogen steel LNS -- A material for advanced aircraft engine and aerospace bearing applications

    SciTech Connect

    Berns, H.; Ebert, F.J.

    1998-12-31

    Development tendencies for future aircraft jet engines require new design concepts for rolling element bearings because of an overall increase of loads, temperatures, rotational speeds and the use of new high temperature lubricants. This paper reviews some of the key parameters which in the past led to the development and application of the known aircraft bearing steels such as M50, M50 NiL and recently Cronidur 30{reg_sign} (AMS 5898). The performance limits of the currently used aerospace bearing steels and the increasing demands on bearing performance for future aerospace applications gave the impact to the design of a new corrosion resistant steel grade of the nitrogen alloyed type, which is suitable for case hardening by nitrogen--the so called Low nitrogen steel (LNS). The development of the alloy (US pat. 5,503,797), the attainable properties and the corresponding heat treatment process are presented. Achievable hardness, case depth, residual stress pattern and corrosion resistance prove the new LNS to be a promising candidate for the next generation of aircraft engine bearings and for advanced, integrated bearing-gear-shaft design concepts.

  4. Aerospace Community. Aerospace Education I.

    ERIC Educational Resources Information Center

    Mickey, V. V.

    This book, one in the series on Aerospace Education I, emphasizes the two sides of aerospace--military aerospace and civilian aerospace. Chapter 1 includes a brief discussion on the organization of Air Force bases and missile sites in relation to their missions. Chapter 2 examines the community services provided by Air Force bases. The topics…

  5. A Program of Research and Education in Aerospace Structures at the Joint Institute for Advancement of Flight Sciences

    NASA Technical Reports Server (NTRS)

    Tolson, Robert H.

    2000-01-01

    The objectives of the cooperative effort with NASA was to conduct research related to aerospace structures and to increase the quality and quantity of highly trained engineers knowledgeable about aerospace structures. The program has successfully met the objectives and has been of significant benefit to NASA LARC, the GWU and the nation. The program was initiated with 3 students in 1994 under the direction of Dr. Robert Tolson as the Principal Investigator. Since initiation, 14 students have been involved in the program, resulting in 11 MS degrees with 2 more expected in 2000. The 11 MS theses and projects are listed. For technology transfer purposes some research is not reported in thesis form. Graduates from the program have been hired at aerospace and other companies across the nation, providing GWU and LARC with important industry and government contacts.

  6. Guided ultrasonic waves for the monitoring of hidden fatigue crack growth in multi-layer aerospace structures

    NASA Astrophysics Data System (ADS)

    Najarre, I.; Kostson, E.; Fromme, P.

    2014-03-01

    Varying loading conditions of aircraft structures result in stress concentration at fastener holes, where multi-layered components are connected, possibly leading to the development of fatigue cracks. The potential of guided ultrasonic waves, propagating along large plate-like structures, for the Structural Health Monitoring (SHM) of aerospace structures has been identified. However, the sensitivity for the detection of small, potentially hidden, defects has to be ascertained. This contribution presents a study of the application of guided ultrasonic waves in multi-layered tensile specimens for the monitoring of fatigue crack growth at fastener holes in the 2nd (bottom) layer of such structures. Fatigue crack growth was monitored optically and the changes in the ultrasonic signal caused by the crack development were quantified. It was shown that hidden fatigue crack detection and monitoring using the low frequency guided waves is possible. The sensitivity and repeatability of the measurements were ascertained, having the potential for fatigue crack growth monitoring at critical and difficult to access fastener locations from a stand-off distance. The robustness of the methodology for practical in-situ ultrasonic monitoring of fatigue crack growth was discussed.

  7. Fuzzy Logic Approaches to Multi-Objective Decision-Making in Aerospace Applications

    NASA Technical Reports Server (NTRS)

    Hardy, Terry L.

    1994-01-01

    Fuzzy logic allows for the quantitative representation of multi-objective decision-making problems which have vague or fuzzy objectives and parameters. As such, fuzzy logic approaches are well-suited to situations where alternatives must be assessed by using criteria that are subjective and of unequal importance. This paper presents an overview of fuzzy logic and provides sample applications from the aerospace industry. Applications include an evaluation of vendor proposals, an analysis of future space vehicle options, and the selection of a future space propulsion system. On the basis of the results provided in this study, fuzzy logic provides a unique perspective on the decision-making process, allowing the evaluator to assess the degree to which each option meets the evaluation criteria. Future decision-making should take full advantage of fuzzy logic methods to complement existing approaches in the selection of alternatives.

  8. Development of a non-explosive release device for aerospace applications

    NASA Technical Reports Server (NTRS)

    Busch, John D.; Purdy, William E.; Johnson, A. David

    1992-01-01

    A simple, non-explosive, high load capacity release mechanism using a shape memory alloy is currently being developed for space flight. This device, the Frangibolt, could replace most pyrotechnic devices in applications where the need for safety, reliability, non-destructive testing, and minimal mechanical shock is more crucial than the need for rapid actuation. Prototype hardware has been designed, tested, and proven in laboratory conditions. Orientation and demonstration of these devices evidenced reliable and repeatable performance, clearly indicating that extensive testing for flight qualification is warranted. Here, the Frangibolt design is discussed, recent test results of laboratory units are described, and the work that must be performed in the upcoming months to qualify the device for aerospace applications is addressed.

  9. Lithium-Ion Polymer Rechargeable Battery Developed for Aerospace and Military Applications

    NASA Technical Reports Server (NTRS)

    Hagedorn, orman H.

    1999-01-01

    A recently completed 3 -year project funded by the Defense Advanced Research Projects Agency (DARPA) under the Technology Reinvestment Program has resulted in the development and scaleup of new lithium-ion polymer battery technology for military and aerospace applications. The contractors for this cost-shared project were Lockheed Martin Missiles & Space and Ultralife Batteries, Inc. The NASA Lewis Research Center provided contract management and technical oversight. The final products of the project were a portable 15-volt (V), 10-ampere-hour (A-hr) military radio battery and a 30-V, 50-A-hr marine/aerospace battery. Lewis will test the 50-A-hr battery. The new lithium-ion polymer battery technology offers a threefold or fourfold reduction in mass and volume, relative to today s commonly used nickel-cadmium, nickel-hydrogen, and nickel-metal hydride batteries. This is of special importance for orbiting satellites. It has been determined for a particular commercial communications satellite that the replacement of 1 kg of battery mass with 1 kg of transponder mass could increase the annual revenue flow by $100 000! Since this lithium-ion polymer technology offers battery mass reductions on the order of hundreds of kilograms for some satellites, the potential revenue increases are impressive.

  10. Evaluation of a Gamma Titanium Aluminide for Hypersonic Structural Applications

    NASA Technical Reports Server (NTRS)

    Johnson, W. Steven; Weeks, Carrell E.

    2005-01-01

    Titanium matrix composites (TMCs) have been extensively evaluated for their potential to replace conventional superalloys in high temperature structural applications, with significant weight-savings while maintaining comparable mechanical properties. New gamma titanium aluminide alloys and an appropriate fiber could offer an improved TMC for use in intermediate temperature applications (400-800 C). The purpose of this investigation is the evaluation of a gamma titanium aluminide alloy with nominal composition Ti-46.5Al-4(Cr,Nb,Ta,B)at.% as a structural material in future aerospace transportation systems, where very light-weight structures are necessary to meet the goals of advanced aerospace programs.

  11. Fracture characteristics of structural aerospace alloys containing deep surface flaws. [aluminum-titanium alloys

    NASA Technical Reports Server (NTRS)

    Masters, J. N.; Bixler, W. D.; Finger, R. W.

    1973-01-01

    Conditions controlling the growth and fracture of deep surface flaws in aerospace alloys were investigated. Static fracture tests were performed on 7075-T651 and 2219-T87 aluminum, and 6Ai-4V STA titanium . Cyclic flaw growth tests were performed on the two latter alloys, and sustain load tests were performed on the titanium alloy. Both the cyclic and the sustain load tests were performed with and without a prior proof overload cycle to investigate possible growth retardation effects. Variables included in all test series were thickness, flaw depth-to-thickness ratio, and flaw shape. Results were analyzed and compared with previously developed data to determine the limits of applicability of available modified linear elastic fracture solutions.

  12. Manufacturing Challenges Associated with the Use of Metal Matrix Composites in Aerospace Structures

    NASA Technical Reports Server (NTRS)

    Prater, Tracie

    2014-01-01

    Metal Matrix Composites (MMCs) consist of a metal alloy reinforced with ceramic particles or fibers. These materials possess a very high strength to weight ratio, good resistance to impact and wear, and a number of other properties which make them attractive for use in aerospace and defense applications. MMCs have found use in the space shuttle orbiter's structural tubing, the Hubble Space Telescope's antenna mast, control surfaces and propulsion systems for aircraft, and tank armors. The size of MMC components is severely limited by difficulties encountered in joining these materials using fusion welding. Melting of the material results in formation of an undesirable phase (formed when molten Aluminum reacts with the reinforcement) which leaves a strength depleted region along the joint line. Friction Stir Welding (FSW) is a relatively nascent solid state joining technique developed at The Welding Institute (TWI) in 1991. The process was first used at NASA to weld the super lightweight external tank for the Space Shuttle. Today FSW is used to join structural components of the Delta IV, Atlas V, and Falcon IX rockets as well as NASA's Orion Crew Exploration Vehicle and Space Launch System. A current focus of FSW research is to extend the process to new materials, such as MMCs, which are difficult to weld using conventional fusion techniques. Since Friction Stir Welding occurs below the melting point of the workpiece material, this deleterious phase is absent in FSW-ed MMC joints. FSW of MMCs is, however, plagued by rapid wear of the welding tool, a consequence of the large discrepancy in hardness between the steel tool and the reinforcement material. This chapter summarizes the challenges encountered when joining MMCs to themselves or to other materials in structures. Specific attention is paid to the influence of process variables in Friction Stir Welding on the wear process characterizes the effect of process parameters (spindle speed, traverse rate, and length

  13. Plasma Immersion Ion Implantation with Solid Targets for Space and Aerospace Applications

    SciTech Connect

    Oliveira, R. M.; Goncalves, J. A. N.; Ueda, M.; Silva, G.; Baba, K.

    2009-01-05

    This paper describes successful results obtained by a new type of plasma source, named as Vaporization of Solid Targets (VAST), for treatment of materials for space and aerospace applications, by means of plasma immersion ion implantation and deposition (PIII and D). Here, the solid element is vaporized in a high pressure glow discharge, being further ionized and implanted/deposited in a low pressure cycle, with the aid of an extra electrode. First experiments in VAST were run using lithium as the solid target. Samples of silicon and aluminum alloy (2024) were immersed into highly ionized lithium plasma, whose density was measured by a double Langmuir probe. Measurements performed with scanning electron microscopy (SEM) showed clear modification of the cross-sectioned treated silicon samples. X-ray photoelectron spectroscopy (XPS) analysis revealed that lithium was implanted/deposited into/onto the surface of the silicon. Implantation depth profiles may vary according to the condition of operation of VAST. One direct application of this treatment concerns the protection against radiation damage for silicon solar cells. For the case of the aluminum alloy, X-ray diffraction analysis indicated the appearance of prominent new peaks. Surface modification of A12024 by lithium implantation/deposition can lower the coefficient of friction and improve the resistance to fatigue of this alloy. Recently, cadmium was vaporized and ionized in VAST. The main benefit of this element is associated with the improvement of corrosion resistance of metallic substrates. Besides lithium and cadmium, VAST allows to performing PIII and D with other species, leading to the modification of the near-surface of materials for distinct purposes, including applications in the space and aerospace areas.

  14. A strain energy-based vibrational NDE method applied to an aerospace structure

    SciTech Connect

    Osegueda, R. A.; Andre, G.; Ferregut, C. M.; Carrasco, C.; Pereyra, L.; James, G. III; Grygier, M.; Rocha, R.

    1999-12-02

    An early prototype of the Vertical Stabilizer Assembly (VSA) of the Shuttle Orbiter was modal tested at healthy and damaged states to study vibrational nondestructive damage evaluation in aerospace structures. Frequency Response and Coherence functions were collected with a Laser Vibrometer at 84 points when the healthy and damaged VSA was shaken with a continuous random force from 0 to 300 Hz. The measurements were used to extract the resonant frequencies and modal shapes for the healthy and damaged states. After pairing of the mode shapes between the healthy and damaged states through the Modal Assurance Criterion, the strain energy of the modes were determined through a finite element model of the VSA and normalized. The localization of the damage is achieved through an analysis of the differences between the modal strain energy in the healthy and damaged states and a fusion on the information obtained from several modes. This paper evaluates the detectability and performance of four different methods.

  15. Collection, processing, and reporting of damage tolerant design data for non-aerospace structural materials

    NASA Technical Reports Server (NTRS)

    Huber, P. D.; Gallagher, J. P.

    1994-01-01

    This report describes the organization, format and content of the NASA Johnson damage tolerant database which was created to store damage tolerant property data for non aerospace structural materials. The database is designed to store fracture toughness data (K(sub IC), K(sub c), J(sub IC) and CTOD(sub IC)), resistance curve data (K(sub R) VS. delta a (sub eff) and JR VS. delta a (sub eff)), as well as subcritical crack growth data (a vs. N and da/dN vs. delta K). The database contains complementary material property data for both stainless and alloy steels, as well as for aluminum, nickel, and titanium alloys which were not incorporated into the Damage Tolerant Design Handbook database.

  16. Aerospace - Aviation Education.

    ERIC Educational Resources Information Center

    Martin, Arthur I.; Jones, K. K.

    This document outlines the aerospace-aviation education program of the State of Texas. In this publication the course structures have been revised to fit the quarter system format of secondary schools in Texas. The four courses outlined here have been designed for students who will be consumers of aerospace products, spinoffs, and services or who…

  17. Light weight, high-speed, and self-powered wireless fiber optic sensor (WiFOS) structural health monitor system for avionics and aerospace environments

    NASA Astrophysics Data System (ADS)

    Mendoza, Edgar A.; Kempen, Cornelia; Sun, Sunjian; Esterkin, Yan

    2014-09-01

    This paper describes recent progress towards the development of an innovative light weight, high-speed, and selfpowered wireless fiber optic sensor (WiFOS™) structural health monitor system suitable for the onboard and in-flight unattended detection, localization, and classification of load, fatigue, and structural damage in advanced composite materials commonly used in avionics and aerospace systems. The WiFOS™ system is based on ROI's advancements on monolithic photonic integrated circuit microchip technology, integrated with smart power management, on-board data processing, wireless data transmission optoelectronics, and self-power using energy harvesting tools such as solar, vibration, thermoelectric, and magneto-electric. The self-powered, wireless WiFOS™ system offers a versatile and powerful SHM tool to enhance the reliability and safety of avionics platforms, jet fighters, helicopters, commercial aircraft that use lightweight composite material structures, by providing comprehensive information about the structural integrity of the structure from a large number of locations. Immediate SHM applications are found in rotorcraft and aircraft, ships, submarines, and in next generation weapon systems, and in commercial oil and petrochemical, aerospace industries, civil structures, power utilities, portable medical devices, and biotechnology, homeland security and a wide spectrum of other applications.

  18. Activities of the NASA sponsored SRI technology applications team in transferring aerospace technology to the public sector

    NASA Technical Reports Server (NTRS)

    Berke, J. G.

    1971-01-01

    The organization and functions of an interdisciplinary team for the application of aerospace generated technology to the solution of discrete technological problems within the public sector are presented. The interdisciplinary group formed at Stanford Research Institute, California is discussed. The functions of the group are to develop and conduct a program not only optimizing the match between public sector technological problems in criminalistics, transportation, and the postal services and potential solutions found in the aerospace data base, but ensuring that appropriate solutions are acutally utilized. The work accomplished during the period from July 1, 1970 to June 30, 1971 is reported.

  19. The 1992 NASA Langley Measurement Technology Conference: Measurement Technology for Aerospace Applications in High-Temperature Environments

    NASA Technical Reports Server (NTRS)

    Singh, Jag J. (Editor); Antcliff, Richard R. (Editor)

    1992-01-01

    An intensive 2-day conference to discuss the current status of measurement technology in the areas of temperature/heat flux, stress/strain, pressure, and flowfield diagnostics for high temperature aerospace applications was held at Langley Research Center, Hampton, Virginia, on April 22 and 23, 1993. Complete texts of the papers presented at the Conference are included in these proceedings.

  20. Prediction of the mechanical properties of zeolite pellets for aerospace molecular decontamination applications

    PubMed Central

    Rioland, Guillaume; Faye, Delphine; Patarin, Joël

    2016-01-01

    Zeolite pellets containing 5 wt % of binder (methylcellulose or sodium metasilicate) were formed with a hydraulic press. This paper describes a mathematical model to predict the mechanical properties (uniaxial and diametric compression) of these pellets for arbitrary dimensions (height and diameter) using a design of experiments (DOE) methodology. A second-degree polynomial equation including interactions was used to approximate the experimental results. This leads to an empirical model for the estimation of the mechanical properties of zeolite pellets with 5 wt % of binder. The model was verified by additional experimental tests including pellets of different dimensions created with different applied pressures. The optimum dimensions were found to be a diameter of 10–23 mm, a height of 1–3.5 mm and an applied pressure higher than 200 MPa. These pellets are promising for technological uses in molecular decontamination for aerospace-based applications. PMID:28144526

  1. Prediction of the mechanical properties of zeolite pellets for aerospace molecular decontamination applications.

    PubMed

    Rioland, Guillaume; Dutournié, Patrick; Faye, Delphine; Daou, T Jean; Patarin, Joël

    2016-01-01

    Zeolite pellets containing 5 wt % of binder (methylcellulose or sodium metasilicate) were formed with a hydraulic press. This paper describes a mathematical model to predict the mechanical properties (uniaxial and diametric compression) of these pellets for arbitrary dimensions (height and diameter) using a design of experiments (DOE) methodology. A second-degree polynomial equation including interactions was used to approximate the experimental results. This leads to an empirical model for the estimation of the mechanical properties of zeolite pellets with 5 wt % of binder. The model was verified by additional experimental tests including pellets of different dimensions created with different applied pressures. The optimum dimensions were found to be a diameter of 10-23 mm, a height of 1-3.5 mm and an applied pressure higher than 200 MPa. These pellets are promising for technological uses in molecular decontamination for aerospace-based applications.

  2. Multilayered graphene in K(a)-band: nanoscale coating for aerospace applications.

    PubMed

    Kuzhir, P; Volynets, N; Maksimenko, S; Kaplas, T; Svirko, Yu

    2013-08-01

    We report on the experimental study of electromagnetic (EM) properties of multilayered graphene in K(a)-band synthesized by catalytic chemical vapor deposition (CVD) process in between nanometrically thin Cu catalyst film and dielectric (SiO2) substrate. The quality of the produced multilayered graphene samples was monitored by Raman spectroscopy. The thickness of graphene films was controlled by atomic force microscopy (AFM) and was found to be a few nanometers (up to 5 nm). We discovered, that the fabricated graphene, being only some thousandth of skin depth, provided remarkably high EM shielding efficiency caused by absorption losses at the level of 35-43% of incident power. Being highly conductive at room temperature, multilayer graphene emerges as a promising material for manufacturing ultrathin microwave coatings to be used in aerospace applications.

  3. Boron-bearing species in ceramic matrix composites for long-term aerospace applications

    NASA Astrophysics Data System (ADS)

    Naslain, R.; Guette, A.; Rebillat, F.; Pailler, R.; Langlais, F.; Bourrat, X.

    2004-02-01

    Boron-bearing refractory species are introduced in non-oxide ceramic matrix fibrous composites (such as SiC/SiC composites) to improve their oxidation resistance under load at high temperatures with a view to applications in the aerospace field. B-doped pyrocarbon and hex-BN have been successfully used as interphase (instead of pure pyrocarbon) either as homogeneous or multilayered fiber coatings, to arrest and deflect matrix cracks formed under load (mechanical fuse function) and to give toughness to the materials. A self-healing multilayered matrix is designed and used in a model composite, which combines B-doped pyrocarbon mechanical fuse layers and B- and Si-bearing compound (namely B 4C and SiC) layers forming B 2O 3-based fluid healing phases when exposed to an oxidizing atmosphere. All the materials are deposited by chemical vapor infiltration. Lifetimes under tensile loading of several hundreds hours at high temperatures are reported.

  4. Monitoring of hidden damage in multi-layered aerospace structures using high-frequency guided waves

    NASA Astrophysics Data System (ADS)

    Semoroz, A.; Masserey, B.; Fromme, P.

    2011-04-01

    Aerospace structures contain multi-layered components connected by fasteners, where fatigue cracks and disbonds or localized lack of sealant can develop due to cyclic loading conditions and stress concentration. High frequency guided waves propagating along such a structure allow for the efficient non-destructive testing of large components, such as aircraft wings. The type of multi-layered model structure investigated in this contribution consists of two aluminium plates adhesively bonded with an epoxy based sealant layer. Using commercially available transducer equipment, specific high frequency guided ultrasonic wave modes that penetrate through the complete thickness of the structure were excited. The wave propagation along the structure was measured experimentally using a laser interferometer. Two types of hidden damage were considered: a localized lack of sealant and small surface defects in the metallic layer facing the sealant. The detection sensitivity using standard pulse-echo measurement equipment has been quantified and the detection of small hidden defects from significant stand-off distances has been shown. Fatigue experiments were carried out and the potential of high frequency guided waves for the monitoring of fatigue crack growth at a fastener hole during cyclic loading was discussed.

  5. Aerospace Medicine

    NASA Technical Reports Server (NTRS)

    Michaud, Vince

    2015-01-01

    NASA Aerospace Medicine overview - Aerospace Medicine is that specialty area of medicine concerned with the determination and maintenance of the health, safety, and performance of those who fly in the air or in space.

  6. X-ray simulation for structural integrity for aerospace components - A case study

    NASA Astrophysics Data System (ADS)

    Singh, Surendra; Gray, Joseph

    2016-02-01

    The use of Integrated Computational Materials Engineering (ICME) has rapidly evolved from an emerging technology to the industry standards in Materials, Manufacturing, Chemical, Civil, and Aerospace engineering. Despite this the recognition of the ICME merits has been somewhat lacking within NDE community. This is due in part to the makeup of NDE practitioners. They are a very diverse but regimented group. More than 80% of NDE experts are trained and certified as NDT Level 3's and auditors in order to perform their daily inspection jobs. These jobs involve detection of attribute of interest, which may be a defect or condition or both, in a material. These jobs are performed in strict compliance with procedures that have been developed over many years by trial-and-error with minimal understanding of the underlying physics and interplay between the NDE methods setup parameters. It is not in the nature of these trained Level 3's experts to look for alternate or out-of-the box, solutions. Instead, they follow the procedures for compliance as required by regulatory agencies. This approach is time-consuming, subjective, and is treated as a bottleneck in today's manufacturing environments. As such, there is a need for new NDE tools that provide rapid, high quality solutions for studying structural and dimensional integrity in parts at a reduced cost. NDE simulations offer such options by a shortening NDE technique development-time, attaining a new level in the scientific understanding of physics of interactions between interrogating energy and materials, and reducing costs. In this paper, we apply NDE simulation (XRSIM as an example) for simulating X-Ray techniques for studying aerospace components. These results show that NDE simulations help: 1) significantly shorten NDE technique development-time, 2) assist in training NDE experts, by facilitating the understanding of the underlying physics, and 3) improve both capability and reliability of NDE methods in terms of

  7. Excimer-laser-induced surface treatments on metal and ceramic materials: applications to automotive, aerospace, and microelectronic industries

    NASA Astrophysics Data System (ADS)

    Autric, Michel L.

    1999-09-01

    Surface treatments by laser irradiation can improve materials properties in terms of mechanical and physico- chemical behaviors, these improvements being related to the topography, the hardness, the microstructure, the chemical composition. Up to now, the use of excimer lasers for industrial applications remained marginal in spite of the interest related to the short wavelength (high photon energy and better energetic coupling with materials and reduced thermal effects in the bulk material). Up to now, the main limitations concerned the beam quality, the beam delivery, the gas handling and the relatively high investment cost. At this time, the cost of laser devices is going down and the ultraviolet radiation can be conducted through optical fibers. These two elements give new interest in using excimer laser for industrial applications. The main objective of this research program which we are involved in, is to underline some materials processing applications for automotive, aerospace or microelectronic industries for which it could be more interesting to use excimer lasers (minimized thermal effects). This paper concerns the modifications of the roughness, porosity, hardness, structure, phase, residual stresses, chemical composition of the surface of materials such as metallic alloys (aluminum, steel, cast iron, titanium, and ceramics (oxide, nitride, carbide,...) irradiated by KrF and XeCl excimer lasers.

  8. Further Development of Ko Displacement Theory for Deformed Shape Predictions of Nonuniform Aerospace Structures

    NASA Technical Reports Server (NTRS)

    Ko, William L.; Fleischer, Van Tran

    2009-01-01

    The Ko displacement theory previously formulated for deformed shape predictions of nonuniform beam structures is further developed mathematically. The further-developed displacement equations are expressed explicitly in terms of geometrical parameters of the beam and bending strains at equally spaced strain-sensing stations along the multiplexed fiber-optic sensor line installed on the bottom surface of the beam. The bending strain data can then be input into the displacement equations for calculations of local slopes, deflections, and cross-sectional twist angles for generating the overall deformed shapes of the nonuniform beam. The further-developed displacement theory can also be applied to the deformed shape predictions of nonuniform two-point supported beams, nonuniform panels, nonuniform aircraft wings and fuselages, and so forth. The high degree of accuracy of the further-developed displacement theory for nonuniform beams is validated by finite-element analysis of various nonuniform beam structures. Such structures include tapered tubular beams, depth-tapered unswept and swept wing boxes, width-tapered wing boxes, and double-tapered wing boxes, all under combined bending and torsional loads. The Ko displacement theory, combined with the fiber-optic strain-sensing system, provide a powerful tool for in-flight deformed shape monitoring of unmanned aerospace vehicles by ground-based pilots to maintain safe flights.

  9. Aerospace bibliography, seventh edition

    NASA Technical Reports Server (NTRS)

    Blashfield, J. F. (Compiler)

    1983-01-01

    Space travel, planetary probes, applications satellites, manned spaceflight, the impacts of space exploration, future space activities, astronomy, exobiology, aeronautics, energy, space and the humanities, and aerospace education are covered.

  10. Reliability-based econometrics of aerospace structural systems: Design criteria and test options. Ph.D. Thesis - Georgia Inst. of Tech.

    NASA Technical Reports Server (NTRS)

    Thomas, J. M.; Hanagud, S.

    1974-01-01

    The design criteria and test options for aerospace structural reliability were investigated. A decision methodology was developed for selecting a combination of structural tests and structural design factors. The decision method involves the use of Bayesian statistics and statistical decision theory. Procedures are discussed for obtaining and updating data-based probabilistic strength distributions for aerospace structures when test information is available and for obtaining subjective distributions when data are not available. The techniques used in developing the distributions are explained.

  11. Low electrical resistivity carbon nanotube and polyethylene nanocomposites for aerospace and energy exploration applications

    NASA Astrophysics Data System (ADS)

    Moloney, Padraig G.

    An investigation was conducted towards the development and optimization of low electrical resistivity carbon nanotube (CNT) and thermoplastic composites as potential materials for future wire and cable applications in aerospace and energy exploration. Fundamental properties of the polymer, medium density polyethylene (MDPE), such as crystallinity were studied and improved for composite use. A parallel effort was undertaken on a broad selection of CNT, including single wall, double wall and multi wall carbon nanotubes, and included research of material aspects relevant to composite application and low resistivity such as purity, diameter and chirality. With an emphasis on scalability, manufacturing and purification methods were developed, and a solvent-based composite fabrication method was optimized. CNT MDPE composites were characterized via thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), Raman spectroscopy, and multiple routes of electron microscopy. Techniques including annealing and pressure treatments were used to further improve the composites' resulting electrical performance. Enhancement of conductivity was explored via exposure to a focused microwave beam. A novel doping method was developed using antimony pentafluoride (SbF5) to reduce the resistivity of the bulk CNT. Flexible composites, malleable under heat and pressure, were produced with exceptional electrical resistivities reaching as low as 2*10-6O·m (5*105S/m). A unique gas sensor application utilizing the unique electrical resistivities of the produced CNT-MDPE composites was developed. The materials proved suitable as a low weight and low energy sensing material for dimethyl methylphosphonate (DMMP), a nerve gas simulant.

  12. Development and test of the Ball Aerospace optical frequency comb: a versatile measurement tool for aerospace applications

    NASA Astrophysics Data System (ADS)

    Wachs, Jordan; Leitch, James; Knight, Scott; Pierce, Robert; Adkins, Michael

    2016-07-01

    The Ball Fiber Optical Comb Demo is a lab-based system which is used to develop space applications for optical frequency combs. These developments utilize the broadband optical coherence of the frequency comb to expand the capabilities of ground test and orbital systems used for optical wave-front measurement, control of adaptive optics, precision ranging, and reference frequency stabilization. The work expands upon a NIST-developed all-fiber frequency comb that exhibits high stability in a compact, enclosed package. Previously demonstrated applications for frequency combs include: Spectroscopy, distance and velocity measurement, frequency conversion, and timing transfer. Results from the Ball system show the characterization and performance of a frequency comb system with a technological path-to-space. Demonstrations in high precision metrology and long distance ranging are also presented for application in adaptive and multi-body optical systems.

  13. Correlating Hardness Retention and Phase Transformations of Al and Mg Cast Alloys for Aerospace Applications

    NASA Astrophysics Data System (ADS)

    Kasprzak, W.; Czerwinski, F.; Niewczas, M.; Chen, D. L.

    2015-03-01

    The methodology based on correlating hardness and phase transformations was developed and applied to determine the maximum temperature of hardness retention of selected Al-based and Mg-based alloys for aerospace applications. The Al alloys: A356, F357, and C355 experienced 34-66% reduction of the initial hardness, in comparison to 4-22% hardness reduction observed in Mg alloys: QE22A, EV31A, ZE41A, and WE43B after the same annealing to 450 °C. For Al alloys the hardness reduction showed a steep transition between 220 and 238 °C. In contrast, Mg alloys showed a gradual hardness decrease occurring at somewhat higher temperatures between 238 and 250 °C. The hardness data were correlated with corresponding phase transformation kinetics examined by dilatometer and electrical resistivity measurements. Although Mg alloys preserved hardness to higher temperatures, their room temperature tensile strength and hardness were lower than Al alloys. The experimental methodology used in the present studies appears to be very useful in evaluating the softening temperature of commercial Al- and Mg-based alloys, permitting to assess their suitability for high-temperature applications.

  14. Applications of aerospace technology to petroleum exploration. Volume 1: Efforts and results

    NASA Technical Reports Server (NTRS)

    Jaffe, L. D.

    1976-01-01

    The feasibility of applying aerospace techniques to help solve significant problems in petroleum exploration is studied. Through contacts with petroleum industry and petroleum service industry, important petroleum exploration problems were identified. For each problem, areas of aerospace technology that might aid in its solution were also identified where possible. Topics selected for investigation include: seismic reflection systems; down-hole acoustic techniques; identification of geological analogies; drilling methods; remote geological sensing; and sea floor imaging and mapping. Specific areas of aerospace technology are applied to 21 concepts formulated from the topics of concern.

  15. A self-diagnostic adhesive for monitoring bonded joints in aerospace structures

    NASA Astrophysics Data System (ADS)

    Zhuang, Yitao; Li, Yu-hung; Kopsaftopoulos, Fotis; Chang, Fu-Kuo

    2016-04-01

    Bondline integrity is still one of the most critical concerns in the design of aircraft structures up to date. Due to the lack of confidence on the integrity of the bondline both during fabrication and service, the industry standards and regulations still require assembling the composite using conventional fasteners. Furthermore, current state-of-the-art non-destructive evaluation (NDE) and structural health monitoring (SHM) techniques are incapable of offering mature solutions on the issue of bondline integrity monitoring. Therefore, the objective of this work is the development of an intelligent adhesive film with integrated micro-sensors for monitoring the integrity of the bondline interface. The proposed method makes use of an electromechanical-impedance (EMI) based method, which is a rapidly evolving approach within the SHM family. Furthermore, an innovative screen-printing technique to fabricate piezoelectric ceramic sensors with minimal thickness has been developed at Stanford. The approach presented in this study is based on the use of (i) micro screen-printed piezoelectric sensors integrated into adhesive leaving a minimal footprint on the material, (ii) numerical and analytical modeling of the EMI spectrum of the adhesive bondline, (iii) novel diagnostic algorithms for monitoring the bondline integrity based on advanced signal processing techniques, and (iv) the experimental assessment via prototype adhesively bonded structures in static (varying loads) and dynamic (fatigue) environments. The proposed method will provide a huge confidence on the use of bonded joints for aerospace structures and lead to a paradigm change in their design by enabling enormous weight savings while maximizing the economic and performance efficiency.

  16. Fiber Bragg Grating Sensor System for Monitoring Smart Composite Aerospace Structures

    NASA Technical Reports Server (NTRS)

    Moslehi, Behzad; Black, Richard J.; Gowayed, Yasser

    2012-01-01

    Lightweight, electromagnetic interference (EMI) immune, fiber-optic, sensor- based structural health monitoring (SHM) will play an increasing role in aerospace structures ranging from aircraft wings to jet engine vanes. Fiber Bragg Grating (FBG) sensors for SHM include advanced signal processing, system and damage identification, and location and quantification algorithms. Potentially, the solution could be developed into an autonomous onboard system to inspect and perform non-destructive evaluation and SHM. A novel method has been developed to massively multiplex FBG sensors, supported by a parallel processing interrogator, which enables high sampling rates combined with highly distributed sensing (up to 96 sensors per system). The interrogation system comprises several subsystems. A broadband optical source subsystem (BOSS) and routing and interface module (RIM) send light from the interrogation system to a composite embedded FBG sensor matrix, which returns measurand-dependent wavelengths back to the interrogation system for measurement with subpicometer resolution. In particular, the returned wavelengths are channeled by the RIM to a photonic signal processing subsystem based on powerful optical chips, then passed through an optoelectronic interface to an analog post-detection electronics subsystem, digital post-detection electronics subsystem, and finally via a data interface to a computer. A range of composite structures has been fabricated with FBGs embedded. Stress tensile, bending, and dynamic strain tests were performed. The experimental work proved that the FBG sensors have a good level of accuracy in measuring the static response of the tested composite coupons (down to submicrostrain levels), the capability to detect and monitor dynamic loads, and the ability to detect defects in composites by a variety of methods including monitoring the decay time under different dynamic loading conditions. In addition to quasi-static and dynamic load monitoring, the

  17. Point-of-care ultrasound in aerospace medicine: known and potential applications.

    PubMed

    Wagner, Michael S; Garcia, Kathleen; Martin, David S

    2014-07-01

    Since its initial introduction into the bedside assessment of the trauma patient via the Focused Assessment with Sonography for Trauma (FAST) exam, the use of point-of-care ultrasound has expanded rapidly. A growing body of literature demonstrates ultrasound can be used by nonradiologists as an extension of the physical exam to accurately diagnose or exclude a variety of conditions. These conditions include, but are not limited to, hemoperitoneum, pneumothorax, pulmonary edema, long-bone fracture, deep vein thrombosis, and elevated intracranial pressure. As ultrasound machines have become more compact and portable, their use has extended outside of hospitals to places where the physical exam and diagnostic capabilities may be limited, including the aviation environment. A number of studies using focused sonography have been performed to meet the diagnostic challenges of space medicine. The following article reviews the available literature on portable ultrasound use in aerospace medicine and highlights both known and potential applications of point-of-care ultrasound for the aeromedical clinician.

  18. Intelligent HIP processing of a Spraycast-X{reg_sign} superalloy for aerospace applications

    SciTech Connect

    Zahrah, T.F.; Dalal, R.; Kissinger, R.

    1996-12-31

    An eddy current sensor system has been developed to monitor densification during hot isostatic pressing (HIP) of Spraycast-X{reg_sign} superalloy components for aerospace applications. The sensor system was designed, implemented and demonstrated by MATSYS personnel at the Howmet Corporation HIP facility. The eddy current sensor was used to monitor densification of Spraycast-X{reg_sign} Rene`41 ring segments from 95 to 98 percent relative density to full density. The sensor data were verified and validated by metallographic examinations of HIPed specimens. The grain size of the Spraycast-X{reg_sign} Rene`41 was not affected by HIP at both 1,066 C (1,950 F) and 1,121 C (2,050 F). Tensile strengths and 0.2% creep rupture properties were not sensitive to changes in HIP processing conditions. However, tensile ductilities and low cycle properties showed a strong correlation to HIP time at 1,121 C/103 MPa (2,050 F/15 KSI). As hole time at maximum temperature and pressure was increased from 1 to 4 hours, tensile ductilities and low cycle fatigue lives increased. The sensor system can be integrated with an intelligent closed loop control system to monitor and control densification rate and shape distortion.

  19. The Advantages of Non-Flow-Through Fuel Cell Power Systems for Aerospace Applications

    NASA Technical Reports Server (NTRS)

    Hoberecht, Mark; Burke, Kenneth; Jakupca, Ian

    2011-01-01

    NASA has been developing proton-exchange-membrane (PEM) fuel cell power systems for the past decade, as an upgraded technology to the alkaline fuel cells which presently provide power for the Shuttle Orbiter. All fuel cell power systems consist of one or more fuel cell stacks in combination with appropriate balance-of-plant hardware. Traditional PEM fuel cells are characterized as flow-through, in which recirculating reactant streams remove product water from the fuel cell stack. NASA recently embarked on the development of non-flow-through fuel cell systems, in which reactants are dead-ended into the fuel cell stack and product water is removed by internal wicks. This simplifies the fuel cell power system by eliminating the need for pumps to provide reactant circulation, and mechanical water separators to remove the product water from the recirculating reactant streams. By eliminating these mechanical components, the resulting fuel cell power system has lower mass, volume, and parasitic power requirements, along with higher reliability and longer life. These improved non-flow-through fuel cell power systems therefore offer significant advantages for many aerospace applications.

  20. Velcro-Inspired SiC Fuzzy Fibers for Aerospace Applications.

    PubMed

    Hart, Amelia H C; Koizumi, Ryota; Hamel, John; Owuor, Peter Samora; Ito, Yusuke; Ozden, Sehmus; Bhowmick, Sanjit; Syed Amanulla, Syed Asif; Tsafack, Thierry; Keyshar, Kunttal; Mital, Rahul; Hurst, Janet; Vajtai, Robert; Tiwary, Chandra Sekhar; Ajayan, Pulickel M

    2017-04-05

    The most recent and innovative silicon carbide (SiC) fiber ceramic matrix composites, used for lightweight high-heat engine parts in aerospace applications, are woven, layered, and then surrounded by a SiC ceramic matrix composite (CMC). To further improve both the mechanical properties and thermal and oxidative resistance abilities of this material, SiC nanotubes and nanowires (SiCNT/NWs) are grown on the surface of the SiC fiber via carbon nanotube conversion. This conversion utilizes the shape memory synthesis (SMS) method, starting with carbon nanotube (CNT) growth on the SiC fiber surface, to capitalize on the ease of dense surface morphology optimization and the ability to effectively engineer the CNT-SiC fiber interface to create a secure nanotube-fiber attachment. Then, by converting the CNTs to SiCNT/NWs, the relative morphology, advantageous mechanical properties, and secure connection of the initial CNT-SiC fiber architecture are retained, with the addition of high temperature and oxidation resistance. The resultant SiCNT/NW-SiC fiber can be used inside the SiC ceramic matrix composite for a high-heat turbo engine part with longer fatigue life and higher temperature resistance. The differing sides of the woven SiCNT/NWs act as the "hook and loop" mechanism of Velcro but in much smaller scale.

  1. NASA Applications of Structural Health Monitoring Technology

    NASA Technical Reports Server (NTRS)

    Richards, W Lance; Madaras, Eric I.; Prosser, William H.; Studor, George

    2013-01-01

    This presentation provides examples of research and development that has recently or is currently being conducted at NASA, with a special emphasis on the application of structural health monitoring (SHM) of aerospace vehicles. SHM applications on several vehicle programs are highlighted, including Space Shuttle Orbiter, the International Space Station, Uninhabited Aerial Vehicles, and Expendable Launch Vehicles. Examples of current and previous work are presented in the following categories: acoustic emission impact detection, multi-parameter fiber optic strain-based sensing, wireless sensor system development, and distributed leak detection.

  2. NASA Applications of Structural Health Monitoring Technology

    NASA Technical Reports Server (NTRS)

    Richards, W Lance; Madaras, Eric I.; Prosser, William H.; Studor, George

    2013-01-01

    This presentation provides examples of research and development that has recently or is currently being conducted at NASA, with a special emphasis on the application of structural health monitoring (SHM) of aerospace vehicles. SHM applications on several vehicle programs are highlighted, including Space Shuttle Orbiter, International Space Station, Uninhabited Aerial Vehicles, and Expandable Launch Vehicles. Examples of current and previous work are presented in the following categories: acoustic emission impact detection, multi-parameter fiber optic strain-based sensing, wireless sensor system development, and distributed leak detection.

  3. Application of powder metallurgy technique to produce improved bearing elements for cryogenic aerospace engine turbopumps

    NASA Technical Reports Server (NTRS)

    Moxson, V. S.; Moracz, D. J.; Bhat, B. N.; Dolan, F. J.; Thom, R.

    1987-01-01

    Traditionally, vacuum melted 440C stainless steel is used for high performance bearings for aerospace cryogenic systems where corrosion due to condensation is a major concern. For the Space Shuttle Main Engine (SSME), however, 440C performance in the high-pressure turbopumps has been marginal. A basic assumption of this study was that powder metallurgy, rather than cast/wrought, processing would provide the finest, most homogeneous bearing alloy structure. Preliminary testing of P/M alloys (hardness, corrosion resistance, wear resistance, fatigue resistance, and fracture toughness) was used to 'de-select' alloys which did perform as well as baseline 440C. Five out of eleven candidate materials (14-4/6V, X-405, MRC-2001, T-440V, and D-5) based on preliminary screening were selected for the actual rolling-sliding five-ball testing. The results of this test were compared with high-performance vacuum-melted M50 bearing steel. The results of the testing indicated outstanding performance of two P/M alloys, X-405 and MRC-2001, which eventually will be further evaluated by full-scale bearing testing.

  4. Fiber glass reinforced structural materials for aerospace application

    NASA Technical Reports Server (NTRS)

    Bartlett, D. H.

    1968-01-01

    Evaluation of fiber glass reinforced plastic materials concludes that fiber glass construction is lighter than aluminum alloy construction. Low thermal conductivity and strength makes the fiber glass material useful in cryogenic tank supports.

  5. Multiwavelength Pyrometer Developed for Use at Elevated Temperatures in Aerospace Applications

    NASA Technical Reports Server (NTRS)

    Ng, Daniel L.

    2003-01-01

    Researchers at the NASA Glenn Research Center have developed a unique multiwavelength pyrometer for aerospace applications. It has been shown to be a useful and versatile instrument for measuring the surface temperatures of ceramic zirconia thermal barrier coatings (TBCs) and alumina, even when their emissivity is unknown. The introduction of fiber optics into the pyrometer has greatly increased the ease of using this instrument. Direct comparison of measurements obtained using the pyrometer and thin film thermocouples on a sample provided independent verification of pyrometry temperature measurement. Application of the pyrometer has also included simultaneous surface and bulk temperature measurement in a transparent material, the measurement of combustion gas temperatures in the flames of an atmospheric burner, the measurement of the temperature distribution appearing on a large surface from the recording of just a single radiation spectrum emitted from this nonuniform temperature surface, and the measurement of some optical properties for special aeronautical materials-such as nanostructured layers. The multiwavelength pyrometer temperature is obtained from a radiation spectrum recorded over a broad wavelength region by transforming it into a straight line segment(s) in part or all of the spectral region. The intercept of the line segment(s) with the vertical axis at zero wavelength gives the inverse of the temperature. In a two-color pyrometer, the two data points are also amenable to this analysis to determine the unknown temperature. Implicit in a two-color pyrometer is the assumption of wavelength-independent emissivity. Its two (and minimum) pieces of data are sufficient to determine this straight line. However, a multiwavelength pyrometer not only has improved accuracy but also confirms that the wavelength-independent emissivity assumption is valid when a multitude of data points are shown to lie on a simple straight line.

  6. Low vibration microminiature split Stirling cryogenic cooler for infrared aerospace applications

    NASA Astrophysics Data System (ADS)

    Veprik, A.; Zechtzer, S.; Pundak, N.; Kirkconnel, C.; Freeman, J.; Riabzev, S.

    2011-06-01

    The operation of the thermo-mechanical unit of a cryogenic cooler may originate a resonant excitation of the spacecraft frame, optical bench or components of the optical train. This may result in degraded functionality of the inherently vibration sensitive space-borne infrared imager directly associated with the cooler or neighboring instrumentation typically requiring a quiet micro-g environment. The best practice for controlling cooler induced vibration relies on the principle of active momentum cancellation. In particular, the pressure wave generator typically contains two oppositely actuated piston compressors, while the single piston expander is counterbalanced by an auxiliary active counter-balancer. Active vibration cancellation is supervised by a dedicated DSP feed-forward controller, where the error signals are delivered by the vibration sensors (accelerometers or load cells). This can result in oversized, overweight and overpriced cryogenic coolers with degraded electromechanical performance and impaired reliability. The authors are advocating a reliable, compact, cost and power saving approach capitalizing on the combined application of a passive tuned dynamic absorber and a low frequency vibration isolator. This concept appears to be especially suitable for low budget missions involving mini and micro satellites, where price, size, weight and power consumption are of concern. The authors reveal the results of theoretical study and experimentation on the attainable performance using a fullscale technology demonstrator relying on a Ricor model K527 tactical split Stirling cryogenic cooler. The theoretical predictions are in fair agreement with the experimental data. From experimentation, the residual vibration export is quite suitable for demanding wide range of aerospace applications. The authors give practical recommendations on heatsinking and further maximizing performance.

  7. Use of a Multiwavelength Pyrometer in Several Elevated Temperature Aerospace Applications

    NASA Technical Reports Server (NTRS)

    Ng, Daniel; Fralick, Gustave

    2001-01-01

    A multiwavelength pyrometer was developed for applications unique to aerospace environments. It was shown to be a useful and versatile technique for measuring temperature, even when the emissivity is unknown. It has also been used to measure the surface temperatures of ceramic zircomia thermal barrier coatings and alumina. The close agreement between pyrometer and thin film thermocouple temperatures provided an independent check. Other applications of the multiwavelength pyrometer are simultaneous surface and bulk temperature measurements of a transparent material, and combustion gas temperature measurement using a special probe interfaced to the multiwavelength pyrometer via an optical fiber. The multiwavelength pyrometer determined temperature by transforming the radiation spectrum in a broad wavelength region to produce a straight line (in a certain spectral region), whose intercept in the vertical axis gives the temperature. Implicit in a two-color pyrometer is the assumption of wavelength independent emissivity. Though the two data points of a two-color pyrometer similarly processed would result immediately in a similar straight line to give the unknown temperature, the two-color pyrometer lacks the greater data redundancy of the multiwavelength pyrometer, which enables it to do so with improved accuracy. It also confirms that emissivity is indeed wavelength independent, as evidenced by a multitude of the data lying on a simple straight line. The multiwavelength pyrometer was also used to study the optical transmission properties of a nanostructured material from which a quadratic exponential functional frequency dependence of its spectral transmission was determined. Finally, by operating the multiwavelength pyrometer in a very wide field of view mode, the surface temperature distribution of a large hot surface was obtained through measurement of just a single radiation spectrum.

  8. Organizational structure and operation of defense/aerospace information centers in the United States of America

    NASA Technical Reports Server (NTRS)

    Sauter, H. E.; Lushina, L. N.

    1983-01-01

    U.S. Government aerospace and defense information centers are addressed. DTIC and NASA are described in terms of their history, operational authority, information services provided, user community, sources of information collected, efforts under way to improve services, and external agreements regarding the exchange of documents and/or data bases. Contents show how DTIC and NASA provide aerospace/defense information services in support of U.S. research and development efforts. In a general introduction, the importance of scientific and technical information and the need for information centers to acquire, handle, and disseminate it are stressed.

  9. Development of a Solid-Oxide Fuel Cell/Gas Turbine Hybrid System Model for Aerospace Applications

    NASA Technical Reports Server (NTRS)

    Freeh, Joshua E.; Pratt, Joseph W.; Brouwer, Jacob

    2004-01-01

    Recent interest in fuel cell-gas turbine hybrid applications for the aerospace industry has led to the need for accurate computer simulation models to aid in system design and performance evaluation. To meet this requirement, solid oxide fuel cell (SOFC) and fuel processor models have been developed and incorporated into the Numerical Propulsion Systems Simulation (NPSS) software package. The SOFC and reformer models solve systems of equations governing steady-state performance using common theoretical and semi-empirical terms. An example hybrid configuration is presented that demonstrates the new capability as well as the interaction with pre-existing gas turbine and heat exchanger models. Finally, a comparison of calculated SOFC performance with experimental data is presented to demonstrate model validity. Keywords: Solid Oxide Fuel Cell, Reformer, System Model, Aerospace, Hybrid System, NPSS

  10. NASA Application Team Program: Application of aerospace technology in biology and medicine

    NASA Technical Reports Server (NTRS)

    1973-01-01

    The results of the medically related activities of the NASA Application Team Program in technology application for the reporting period September 1, 1972, to August 31, 1973 are reported. The accomplishments of the application team during the reporting period are as follows: The team has identified 39 new problems for investigation, has accomplished 7 technology applications, 4 potential technology applications, 2 impacts, has closed 38 old problems, and has a total of 59 problems under active investigation.

  11. Military Aerospace. Aerospace Education II.

    ERIC Educational Resources Information Center

    Smith, J. C.

    This book is a revised publication in the series on Aerospace Education II. It describes the employment of aerospace forces, their methods of operation, and some of the weapons and equipment used in combat and combat support activities. The first chapter describes some of the national objectives and policies served by the Air Force in peace and…

  12. Aerospace Environment. Aerospace Education I.

    ERIC Educational Resources Information Center

    Savler, D. S.; Smith, J. C.

    This book is one in the series on Aerospace Education I. It briefly reviews current knowledge of the universe, the earth and its life-supporting atmosphere, and the arrangement of celestial bodies in outer space and their physical characteristics. Chapter 1 includes a brief survey of the aerospace environment. Chapters 2 and 3 examine the…

  13. Structural Analysis Methods for Structural Health Management of Future Aerospace Vehicles

    NASA Technical Reports Server (NTRS)

    Tessler, Alexander

    2007-01-01

    Two finite element based computational methods, Smoothing Element Analysis (SEA) and the inverse Finite Element Method (iFEM), are reviewed, and examples of their use for structural health monitoring are discussed. Due to their versatility, robustness, and computational efficiency, the methods are well suited for real-time structural health monitoring of future space vehicles, large space structures, and habitats. The methods may be effectively employed to enable real-time processing of sensing information, specifically for identifying three-dimensional deformed structural shapes as well as the internal loads. In addition, they may be used in conjunction with evolutionary algorithms to design optimally distributed sensors. These computational tools have demonstrated substantial promise for utilization in future Structural Health Management (SHM) systems.

  14. Applications of hybrid and digital computation methods in aerospace-related sciences and engineering. [problem solving methods at the University of Houston

    NASA Technical Reports Server (NTRS)

    Huang, C. J.; Motard, R. L.

    1978-01-01

    The computing equipment in the engineering systems simulation laboratory of the Houston University Cullen College of Engineering is described and its advantages are summarized. The application of computer techniques in aerospace-related research psychology and in chemical, civil, electrical, industrial, and mechanical engineering is described in abstracts of 84 individual projects and in reprints of published reports. Research supports programs in acoustics, energy technology, systems engineering, and environment management as well as aerospace engineering.

  15. Estimation of probability of failure for damage-tolerant aerospace structures

    NASA Astrophysics Data System (ADS)

    Halbert, Keith

    potential to improve aerospace structural safety and reduce maintenance costs by providing a more accurate assessment of the risk of failure and the likelihood of repairs throughout the life of an aircraft.

  16. Aerospace Technology.

    ERIC Educational Resources Information Center

    Paschke, Jean; And Others

    1991-01-01

    Describes the Sauk Rapids (Minnesota) High School aviation and aerospace curriculum that was developed by Curtis Olson and the space program developed by Gerald Mayall at Philadelphia's Northeast High School. Both were developed in conjunction with NASA. (JOW)

  17. Application of numerical methods to heat transfer and thermal stress analysis of aerospace vehicles

    NASA Technical Reports Server (NTRS)

    Wieting, A. R.

    1979-01-01

    The paper describes a thermal-structural design analysis study of a fuel-injection strut for a hydrogen-cooled scramjet engine for a supersonic transport, utilizing finite-element methodology. Applications of finite-element and finite-difference codes to the thermal-structural design-analysis of space transports and structures are discussed. The interaction between the thermal and structural analyses has led to development of finite-element thermal methodology to improve the integration between these two disciplines. The integrated thermal-structural analysis capability developed within the framework of a computer code is outlined.

  18. Hardware Specific Integration Strategy for Impedance-Based Structural Health Monitoring of Aerospace Systems

    NASA Technical Reports Server (NTRS)

    Owen, Robert B.; Gyekenyesi, Andrew L.; Inman, Daniel J.; Ha, Dong S.

    2011-01-01

    The Integrated Vehicle Health Management (IVHM) Project, sponsored by NASA's Aeronautics Research Mission Directorate, is conducting research to advance the state of highly integrated and complex flight-critical health management technologies and systems. An effective IVHM system requires Structural Health Monitoring (SHM). The impedance method is one such SHM technique for detection and monitoring complex structures for damage. This position paper on the impedance method presents the current state of the art, future directions, applications and possible flight test demonstrations.

  19. New Parallel Algorithms for Structural Analysis and Design of Aerospace Structures

    NASA Technical Reports Server (NTRS)

    Nguyen, Duc T.

    1998-01-01

    Subspace and Lanczos iterations have been developed, well documented, and widely accepted as efficient methods for obtaining p-lowest eigen-pair solutions of large-scale, practical engineering problems. The focus of this paper is to incorporate recent developments in vectorized sparse technologies in conjunction with Subspace and Lanczos iterative algorithms for computational enhancements. Numerical performance, in terms of accuracy and efficiency of the proposed sparse strategies for Subspace and Lanczos algorithm, is demonstrated by solving for the lowest frequencies and mode shapes of structural problems on the IBM-R6000/590 and SunSparc 20 workstations.

  20. Clustering-based multiple imputation via gray relational analysis for missing data and its application to aerospace field.

    PubMed

    Tian, Jing; Yu, Bing; Yu, Dan; Ma, Shilong

    2013-01-01

    A large number of scientific researches and industrial applications commonly suffer from missing data. Some inappropriate techniques of missing value treatment compromise data quality, which detrimentally influences the knowledge discovery. In this paper, we propose a missing data completion method named CBGMI. Firstly, it separates the nonmissing data instances into several clusters by excluding the missing-valued entries. Then, it utilizes the entropy of the proximal category for each incomplete instance in terms of the similarity metric based on gray relational analysis. Experiments on UCI datasets and aerospace datasets demonstrate that the superiority of our algorithm to other approaches on validity.

  1. Clustering-Based Multiple Imputation via Gray Relational Analysis for Missing Data and Its Application to Aerospace Field

    PubMed Central

    Tian, Jing; Yu, Dan; Ma, Shilong

    2013-01-01

    A large number of scientific researches and industrial applications commonly suffer from missing data. Some inappropriate techniques of missing value treatment compromise data quality, which detrimentally influences the knowledge discovery. In this paper, we propose a missing data completion method named CBGMI. Firstly, it separates the nonmissing data instances into several clusters by excluding the missing-valued entries. Then, it utilizes the entropy of the proximal category for each incomplete instance in terms of the similarity metric based on gray relational analysis. Experiments on UCI datasets and aerospace datasets demonstrate that the superiority of our algorithm to other approaches on validity. PMID:23737724

  2. In-situ phosphatizing coatings for aerospace, OEM and coil coating applications

    NASA Astrophysics Data System (ADS)

    Neuder, Heather Aurelia

    dispersed into an ISPC and the performance of the final coating formulation is evaluated. Successful ISPCs formulated for multiple coating systems exhibited excellent adhesion, hardness and gloss, which supports their suitability as a chrome-free, single-step alternative for aerospace, original equipment manufacturing (OEM) and coil coating applications.

  3. Combinatorial Optimization Algorithms for Dynamic Multiple Fault Diagnosis in Automotive and Aerospace Applications

    NASA Astrophysics Data System (ADS)

    Kodali, Anuradha

    facility, respectively. The set-covering matrix encapsulates the relationship among the rows (tests or demand points) and columns (faults or locations) of the system at each time. By relaxing the coupling constraints using Lagrange multipliers, the DSC problem can be decoupled into independent subproblems, one for each column. Each subproblem is solved using the Viterbi decoding algorithm, and a primal feasible solution is constructed by modifying the Viterbi solutions via a heuristic. The proposed Viterbi-Lagrangian relaxation algorithm (VLRA) provides a measure of suboptimality via an approximate duality gap. As a major practical extension of the above problem, we also consider the problem of diagnosing faults with delayed test outcomes, termed delay-dynamic set-covering (DDSC), and experiment with real-world problems that exhibit masking faults. Also, we present simulation results on OR-library datasets (set-covering formulations are predominantly validated on these matrices in the literature), posed as facility location problems. Finally, we implement these algorithms to solve problems in aerospace and automotive applications. Firstly, we address the diagnostic ambiguity problem in aerospace and automotive applications by developing a dynamic fusion framework that includes dynamic multiple fault diagnosis algorithms. This improves the correct fault isolation rate, while minimizing the false alarm rates, by considering multiple faults instead of the traditional data-driven techniques based on single fault (class)-single epoch (static) assumption. The dynamic fusion problem is formulated as a maximum a posteriori decision problem of inferring the fault sequence based on uncertain outcomes of multiple binary classifiers over time. The fusion process involves three steps: the first step transforms the multi-class problem into dichotomies using error correcting output codes (ECOC), thereby solving the concomitant binary classification problems; the second step fuses the

  4. Examples of Current and Future Uses of Neural-Net Image Processing for Aerospace Applications

    NASA Technical Reports Server (NTRS)

    Decker, Arthur J.

    2004-01-01

    Feed forward artificial neural networks are very convenient for performing correlated interpolation of pairs of complex noisy data sets as well as detecting small changes in image data. Image-to-image, image-to-variable and image-to-index applications have been tested at Glenn. Early demonstration applications are summarized including image-directed alignment of optics, tomography, flow-visualization control of wind-tunnel operations and structural-model-trained neural networks. A practical application is reviewed that employs neural-net detection of structural damage from interference fringe patterns. Both sensor-based and optics-only calibration procedures are available for this technique. These accomplishments have generated the knowledge necessary to suggest some other applications for NASA and Government programs. A tomography application is discussed to support Glenn's Icing Research tomography effort. The self-regularizing capability of a neural net is shown to predict the expected performance of the tomography geometry and to augment fast data processing. Other potential applications involve the quantum technologies. It may be possible to use a neural net as an image-to-image controller of an optical tweezers being used for diagnostics of isolated nano structures. The image-to-image transformation properties also offer the potential for simulating quantum computing. Computer resources are detailed for implementing the black box calibration features of the neural nets.

  5. Development of a 70 Ah Li-Ion Cell for Aerospace Applications

    NASA Technical Reports Server (NTRS)

    DeGruson, Jim

    2000-01-01

    A viewgraph presentation outlines the development of Li-ion cells at the Li-Ion Technology Center in Missouri. The Li-ion test area is described, as well as the aerospace design and cell construction equipment. Test results are shown for typical charge and discharge, pulse test, and calculated impedance at various temperatures. Near future activities are discussed, including the incorporation of an alternate electrolyte and the optimization of the anode and cathode.

  6. 1993 IEEE Aerospace Applications Conference, 14th, Steamboat Springs, CO, Jan. 31-Feb. 5, 1993, Digest

    NASA Astrophysics Data System (ADS)

    Topics discussed include communications and radar systems, devices, and components. Attention is also given to system concepts and aerospace manufacturing and instrumentation. Particular papers are presented on the performance modeling of simultaneous TDRSS support of the Space Station and the Space Shuttle, a wide swath SAR and radar altimeter, microwave feed systems for NASA's beam-waveguide reflector antennas, the development of the Cassini flight computer requirements, and EMI shielding materials.

  7. Multi-Segment Hemodynamic and Volume Assessment With Impedance Plethysmography: Aerospace Applications

    NASA Technical Reports Server (NTRS)

    Ku, Yu-Tsuan E.; Montgomery, Leslie D.; Webbon, Bruce W. (Technical Monitor)

    1995-01-01

    Definition of multi-segmental circulatory and volume changes in the human body provides an understanding of the physiologic responses to various aerospace conditions. We have developed instrumentation and testing procedures at NASA Ames Research Center that may be useful in biomedical research and clinical diagnosis. Specialized two, four, and six channel impedance systems will be described that have been used to measure calf, thigh, thoracic, arm, and cerebral hemodynamic and volume changes during various experimental investigations.

  8. Performances and reliability predictions of optical data transmission links using a system simulator for aerospace applications

    NASA Astrophysics Data System (ADS)

    Bechou, L.; Deshayes, Y.; Aupetit-Berthelemot, C.; Guerin, A.; Tronche, C.

    - requency carrier) on system performances (eye diagram, quality factor and BER). The studied link consists in 4× 2.5 Gbits/s WDM channels with direct modulation and equally spaced (0,8 nm) around the 1550 nm central wavelength. Results clearly show that variation of fundamental parameters such as bias current or central wavelength induces a penalization of dynamic performances of the complete WDM link. In addition different degradation kinetics of aged Laser diodes from a same batch have been implemented to build the final distribution of Q-factor and BER values after 25 years. When considering long optical distance, fiber attenuation, EDFA noise, dispersion, PMD, ... penalize network performances that can be compensated using Forward Error Correction (FEC) coding. Three methods have been investigated in the case of On-Off Keying (OOK) transmission over an unipolar optical channel corrupted by Gaussian noise. Such system simulations highlight the impact of component parameter degradations on the whole network performances allowing to optimize various time and cost consuming sensitivity analyses at the early stage of the system development. Thus the validity of failure criteria in relation with mission profiles can be evaluated representing a significant part of the general PDfR effort in particular for aerospace applications.

  9. Numerical simulation of dynamics of brushless dc motors for aerospace and other applications. Volume 1: Model development and applications, part A

    NASA Technical Reports Server (NTRS)

    Demerdash, N. A. O.; Nehl, T. W.

    1979-01-01

    The development, fabrication and evaluation of a prototype electromechanical actuator (EMA) is discussed. Application of the EMA as a motor for control surfaces in aerospace flight is examined. A mathematical model of the EMA is developed for design optimization. Nonlinearities which complicate the mathematical model are discussed. The dynamics of the EMA from the underlying physical principles are determined and a discussion of similating the control logic by means of equivalent boolean expressions is presented.

  10. Some cable suspension systems and their effects on the flexural frequencies of slender aerospace structures

    NASA Technical Reports Server (NTRS)

    Herr, R. W.

    1974-01-01

    The effects of several cable suspension configurations on the first free-free flexural frequency of uniform beams have been determined by experiment and analysis. The results of this study confirm that in general the larger the test vehicle the larger is the flexural frequency measurement error attributable to a given cable suspension configuration. For horizontally oriented beams representing modern aerospace vehicles of average size and flexibility, the restraining effects of all but the shortest support cables were minor. The restraining effects of support cables of moderate length attached near the base of vertically oriented vehicles were overshadowed by the effects of beam compression due to gravity.

  11. Predicted reliability of aerospace electronics: Application of two advanced probabilistic concepts

    NASA Astrophysics Data System (ADS)

    Suhir, E.

    Two advanced probabilistic design-for-reliability (PDfR) concepts are addressed and discussed in application to the prediction, quantification and assurance of the aerospace electronics reliability: 1) Boltzmann-Arrhenius-Zhurkov (BAZ) model, which is an extension of the currently widely used Arrhenius model and, in combination with the exponential law of reliability, enables one to obtain a simple, easy-to-use and physically meaningful formula for the evaluation of the probability of failure (PoF) of a material or a device after the given time in operation at the given temperature and under the given stress (not necessarily mechanical), and 2) Extreme Value Distribution (EVD) technique that can be used to assess the number of repetitive loadings that result in the material/device degradation and eventually lead to its failure by closing, in a step-wise fashion, the gap between the bearing capacity (stress-free activation energy) of the material or the device and the demand (loading). It is shown that the material degradation (aging, damage accumulation, flaw propagation, etc.) can be viewed, when BAZ model is considered, as a Markovian process, and that the BAZ model can be obtained as the ultimate steady-state solution to the well-known Fokker-Planck equation in the theory of Markovian processes. It is shown also that the BAZ model addresses the worst, but a reasonably conservative, situation. It is suggested therefore that the transient period preceding the condition addressed by the steady-state BAZ model need not be accounted for in engineering evaluations. However, when there is an interest in understanding the transient degradation process, the obtained solution to the Fokker-Planck equation can be used for this purpose. As to the EVD concept, it attributes the degradation process to the accumulation of damages caused by a train of repetitive high-level loadings, while loadings of levels that are considerably lower than their extreme values do not contribute

  12. Environmentally regulated aerospace coatings

    NASA Technical Reports Server (NTRS)

    Morris, Virginia L.

    1995-01-01

    Aerospace coatings represent a complex technology which must meet stringent performance requirements in the protection of aerospace vehicles. Topcoats and primers are used, primarily, to protect the structural elements of the air vehicle from exposure to and subsequent degradation by environmental elements. There are also many coatings which perform special functions, i.e., chafing resistance, rain erosion resistance, radiation and electric effects, fuel tank coatings, maskants, wire and fastener coatings. The scheduled promulgation of federal environmental regulations for aerospace manufacture and rework materials and processes will regulate the emissions of photochemically reactive precursors to smog and air toxics. Aerospace organizations will be required to identify, qualify and implement less polluting materials. The elimination of ozone depleting chemicals (ODC's) and implementation of pollution prevention requirements are added constraints which must be addressed concurrently. The broad categories of operations affected are the manufacture, operation, maintenance, and repair of military, commercial, general aviation, and space vehicles. The federal aerospace regulations were developed around the precept that technology had to be available to support the reduction of organic and air toxic emissions, i.e., the regulations cannot be technology forcing. In many cases, the regulations which are currently in effect in the South Coast Air Quality Management District (SCAQMD), located in Southern California, were used as the baseline for the federal regulations. This paper addresses strategies used by Southern California aerospace organizations to cope with these regulatory impacts on aerospace productions programs. All of these regulatory changes are scheduled for implementation in 1993 and 1994, with varying compliance dates established.

  13. 60NiTi Intermetallic Material Evaluation for Lightweight and Corrosion Resistant Spherical Sliding Bearings for Aerospace Applications

    NASA Technical Reports Server (NTRS)

    DellaCorte, Christopher; Jefferson, Michael

    2015-01-01

    NASA Glenn Research Center and the Kamatics subsidiary of the Kaman Corporation conducted the experimental evaluation of spherical sliding bearings made with 60NiTi inner races. The goal of the project was to assess the feasibility of manufacturing lightweight, corrosion resistant bearings utilizing 60NiTi for aerospace and industrial applications. NASA produced the bearings in collaboration with Abbott Ball Corporation and Kamatics fabricated bearing assemblies utilizing their standard reinforced polymer liner material. The assembled bearings were tested in oscillatory motion at a load of 4.54kN (10,000 lb), according to the requirements of the plain bearing specification SAE AS81820. Several test bearings were exposed to hydraulic fluid or aircraft deicing fluid prior to and during testing. The results show that the 60NiTi bearings exhibit tribological performance comparable to conventional stainless steel (440C) bearings. Further, exposure of 60NiTi bearings to the contaminant fluids had no apparent performance effect. It is concluded that 60NiTi is a feasible bearing material for aerospace and industrial spherical bearing applications.

  14. On-line failure detection and damping measurement of aerospace structures by random decrement signatures

    NASA Technical Reports Server (NTRS)

    Cole, H. A., Jr.

    1973-01-01

    Random decrement signatures of structures vibrating in a random environment are studied through use of computer-generated and experimental data. Statistical properties obtained indicate that these signatures are stable in form and scale and hence, should have wide application in one-line failure detection and damping measurement. On-line procedures are described and equations for estimating record-length requirements to obtain signatures of a prescribed precision are given.

  15. Aerospace Environmental Technology Conference

    NASA Technical Reports Server (NTRS)

    Whitaker, A. F. (Editor)

    1995-01-01

    The mandated elimination of CFC's, Halons, TCA, and other ozone depleting chemicals and specific hazardous materials has required changes and new developments in aerospace materials and processes. The aerospace industry has been involved for several years in providing product substitutions, redesigning entire production processes, and developing new materials that minimize or eliminate damage to the environment. These activities emphasize replacement cleaning solvents and their application verifications, compliant coatings including corrosion protection systems, and removal techniques, chemical propulsion effects on the environment, and the initiation of modifications to relevant processing and manufacturing specifications and standards. The Executive Summary of this Conference is published as NASA CP-3297.

  16. An evaluation of a constrained test method for obtaining free body responses. [with application to aerospace vehicles

    NASA Technical Reports Server (NTRS)

    Berman, A.; Giansante, N.; Bartlett, F. D., Jr.

    1973-01-01

    A method for obtaining free body responses from dynamic tests on a constrained structure is investigated for practical feasibility. The method is based on the principle that a constrained structure can be considered to be a free body acted upon by multiple forces which include the forces of constraint. By measuring these forces and by exciting the structure so as to develop linearly independent sets of forces, the response of the free body to one force at a time can be computed. Techniques for producing these independent forces are discussed. The development of the theory, computer simulations of tests of representative aerospace vehicles (including experimental error), and a description and listing of the computer programs developed are included. The procedure appears to be a practical method for obtaining in-flight characteristics of such vehicles.

  17. Trajectory optimization and guidance law development for national aerospace plane applications

    NASA Technical Reports Server (NTRS)

    Calise, A. J.; Flandro, G. A.; Corban, J. E.

    1988-01-01

    The work completed to date is comprised of the following: a simple vehicle model representative of the aerospace plane concept in the hypersonic flight regime, fuel-optimal climb profiles for the unconstrained and dynamic pressure constrained cases generated using a reduced order dynamic model, an analytic switching condition for transition to rocket powered flight as orbital velocity is approached, simple feedback guidance laws for both the unconstrained and dynamic pressure constrained cases derived via singular perturbation theory and a nonlinear transformation technique, and numerical simulation results for ascent to orbit in the dynamic pressure constrained case.

  18. Space Benefits: The secondary application of aerospace technology in other sectors of the economy

    NASA Technical Reports Server (NTRS)

    1981-01-01

    Some 585 examples of the beneficial use of NASA aerospace technology by public and private organizations are described to demonstrate the effects of mission-oriented programs on technological progress in the United States. General observations regarding technology transfer activity are presented. Benefit cases are listed in 20 categories along with pertinent information such as communication link with NASA; the DRI transfer example file number; and individual case numbers associated with the technology and examples used; and the date of the latest contract with user organizations. Subject, organization, geographic, and field center indexes are included.

  19. Benefits briefing notebook: The secondary application of aerospace technology in other sectors of the economy

    NASA Technical Reports Server (NTRS)

    1976-01-01

    Resource information on the transfer of aerospace technology to other sectors of the U.S. economy is presented. The contents of this notebook are divided into three sections: (1) benefit cases, (2) transfer overview, and (3) indexes. Transfer examples relevant to each subject area are presented. Pertinent transfer data are given. The Transfer Overview section provides a general perspective for technology transfer from NASA to other organizations. In addition to a description of the basic transfer modes, the selection criteria for notebook examples and the kinds of benefit data they contain are also presented.

  20. Aerospace Medicine

    NASA Technical Reports Server (NTRS)

    Davis, Jeffrey R.

    2006-01-01

    This abstract describes the content of a presentation for ground rounds at Mt. Sinai School of Medicine. The presentation contains three sections. The first describes the history of aerospace medicine beginning with early flights with animals. The second section of the presentation describes current programs and planning for future missions. The third section describes the medical challenges of exploration missions.

  1. A review on the fabrication method of bio-sourced hybrid composites for aerospace and automotive applications

    NASA Astrophysics Data System (ADS)

    Zin, M. H.; Razzi, M. F.; Othman, S.; Liew, K.; Abdan, K.; Mazlan, N.

    2016-10-01

    Development of bio-sourced materials over the recent years has shown growing interests due to their eco-friendly characteristics. The combination of bio-sourced material such as kenaf, jute, sisal and many more into current synthetic fibres such as glass and carbon fibre, which is also known as hybrid composites, offers several significant benefits including sustainability, cost reduction, product variety and high specific mechanical properties. There are many methods used to fabricate composite parts nowadays. However, each method has its own requirement and usability. This review paper intends to focus on suitable technique to be adopted in order to fabricate bio-sourced hybrid composites. Some of the fabrication methods are customized in order to suit with the application of natural fibres. The selected methods are also highlighted with the application in aerospace and automotive industry. The process and outcomes are presented comparatively.

  2. Damage Assessment of Aerospace Structural Components by Impedance Based Health Monitoring

    NASA Technical Reports Server (NTRS)

    Gyekenyesi, Andrew L.; Martin, Richard E.; Sawicki, Jerzy T.; Baaklini, George Y.

    2005-01-01

    This paper addresses recent efforts at the NASA Glenn Research Center at Lewis Field relating to the set-up and assessment of electro-mechanical (E/M) impedance based structural health monitoring. The overall aim is the application of the impedance based technique to aeronautic and space based structural components. As initial steps, a laboratory was created, software written, and experiments conducted on aluminum plates in undamaged and damaged states. A simulated crack, in the form of a narrow notch at various locations, was analyzed using piezoelectric-ceramic (PZT: lead, zirconate, titarate) patches as impedance measuring transducers. Descriptions of the impedance quantifying hardware and software are provided as well as experimental results. In summary, an impedance based health monitoring system was assembled and tested. The preliminary data showed that the impedance based technique was successful in recognizing the damage state of notched aluminum plates.

  3. Application of first principle nickel system battery models to aerospace situations

    SciTech Connect

    Stefano, S. Di; Timmerman, P.; Ratnakumar, B.V.

    1995-12-31

    Battery models based on first principles have been under development for the last five to ten years. More recently, the appearance of faster and more sophisticated computational techniques, has allowed significant advances in the field. The usual approach consists of selecting the critical physicochemical phenomena of the given system (chemistry, mass transfer, charge transfer, etc.), setting up the problem as a set of coupled differential equations and obtaining numerical solutions. This approach was successfully implemented for the Pb-Acid system and subsequently for the NiCd system, at the cell level, by Prof. Ralph White of Texas A and M University. This NiCd cell model served as the basis of the NiCd Aerospace Battery model developed at JPL and reported at previous IECEC meetings. At this time several aerospace battery models using the same approach are under development at JPL. The recent models are based on NiH2 and NiMH chemistries. The current set of models uses a simplified treatment of the electrodes, this treatment assumes planar (non porous) electrode geometry. The resulting models have very modest computational requirements, allowing them to operate on personal computers. Results of performance predictions and computational requirements for the new models are discussed.

  4. A Briefing on Metrics and Risks for Autonomous Decision-Making in Aerospace Applications

    NASA Technical Reports Server (NTRS)

    Frost, Susan; Goebel, Kai Frank; Galvan, Jose Ramon

    2012-01-01

    Significant technology advances will enable future aerospace systems to safely and reliably make decisions autonomously, or without human interaction. The decision-making may result in actions that enable an aircraft or spacecraft in an off-nominal state or with slightly degraded components to achieve mission performance and safety goals while reducing or avoiding damage to the aircraft or spacecraft. Some key technology enablers for autonomous decision-making include: a continuous state awareness through the maturation of the prognostics health management field, novel sensor development, and the considerable gains made in computation power and data processing bandwidth versus system size. Sophisticated algorithms and physics based models coupled with these technological advances allow reliable assessment of a system, subsystem, or components. Decisions that balance mission objectives and constraints with remaining useful life predictions can be made autonomously to maintain safety requirements, optimal performance, and ensure mission objectives. This autonomous approach to decision-making will come with new risks and benefits, some of which will be examined in this paper. To start, an account of previous work to categorize or quantify autonomy in aerospace systems will be presented. In addition, a survey of perceived risks in autonomous decision-making in the context of piloted aircraft and remotely piloted or completely autonomous unmanned autonomous systems (UAS) will be presented based on interviews that were conducted with individuals from industry, academia, and government.

  5. Scenario-Based Specification and Evaluation of Architectures for Health Monitoring of Aerospace Structures

    NASA Technical Reports Server (NTRS)

    Mukkamala, Ravi; Sundaram, P.

    2001-01-01

    HUMS systems have been an area of increased research in the recent times due to two main reasons: (a) increase in the occurrences of accidents in the aerospace, and (b) stricter FAA regulations on aircrafts maintenance [2]. There are several problems associated with the maintenance of aircrafts that the HUMS systems can solve through the use of several monitoring technologies.This paper documents our methodology of employing scenarios in the specification and evaluation of architecture for HUMS. Section 2 investigates related works that use scenarios in software development. Section 3 describes how we use scenarios in our work, which is followed by a demonstration of our methods in the development of KUMS in section 4. Conclusion summarizes results.

  6. NASA-UVa light aerospace alloy and structures technology program supplement: Aluminum-based materials for high speed aircraft

    NASA Technical Reports Server (NTRS)

    Starke, E. A., Jr. (Editor)

    1995-01-01

    This report on the NASA-UVa light aerospace alloy and structure technology program supplement: Aluminum-Based Materials for High Speed Aircraft covers the period from July 1, 1992. The objective of the research is to develop aluminum alloys and aluminum matrix composites for the airframe which can efficiently perform in the HSCT environment for periods as long as 60,000 hours (certification for 120,000 hours) and, at the same time, meet the cost and weight requirements for an economically viable aircraft. Current industry baselines focus on flight at Mach 2.4. The research covers four major materials systems: (1) Ingot metallurgy 2XXX, 6XXX, and 8XXX alloys, (2) Powder metallurgy 2XXX alloys, (3) Rapidly solidified, dispersion strengthened Al-Fe-X alloys, and (4) Discontinuously reinforced metal matrix composites. There are ten major tasks in the program which also include evaluation and trade-off studies by Boeing and Douglas aircraft companies.

  7. Low-order design and high-order simulation of active closed-loop control for aerospace structures under construction

    NASA Technical Reports Server (NTRS)

    Balas, Mark J.

    1989-01-01

    Partially constructed/assembled structures in space are complicated enough but their dynamics will also be operating in closed-loop with feedback controllers. The dynamics of such structures are modeled by large-scale finite element models. The model dimension L is extremely large (approximately 10,000) while the numbers of actuators (M) and sensors (P) are small. The model parameters M(sub m) mass matrix, D(sub o) damping matrix, and K(sub o) stiffness matrix, are all symmetric and sparse (banded). Thus simulation of open-loop structure models of very large dimension can be accomplished by special integration techniques for sparse matrices. The problem of simulation of closed-loop control of such structures is complicated by the addition of controllers. Simulation of closed-loop controlled structures is an essential part of the controller design and evaluation process. Current research in the following areas is presented: high-order simulation of actively controlled aerospace structures; low-order controller design and SCI compensation for unmodeled dynamics; prediction of closed-loop stability using asymptotic eigenvalue series; and flexible robot manipulator control experiment.

  8. Friction Stir Welding of Large Scale Cryogenic Tanks for Aerospace Applications

    NASA Technical Reports Server (NTRS)

    Russell, Carolyn; Ding, R. Jeffrey

    1998-01-01

    The Marshall Space Flight Center (MSFC) has established a facility for the joining of large-scale aluminum cryogenic propellant tanks using the friction stir welding process. Longitudinal welds, approximately five meters in length, have been made by retrofitting an existing vertical fusion weld system, designed to fabricate tank barrel sections ranging from two to ten meters in diameter. The structural design requirements of the tooling, clamping and travel system will be described in this presentation along with process controls and real-time data acquisition developed for this application. The approach to retrofitting other large welding tools at MSFC with the friction stir welding process will also be discussed.

  9. Control design for robust stability in linear regulators: Application to aerospace flight control

    NASA Technical Reports Server (NTRS)

    Yedavalli, R. K.

    1986-01-01

    Time domain stability robustness analysis and design for linear multivariable uncertain systems with bounded uncertainties is the central theme of the research. After reviewing the recently developed upper bounds on the linear elemental (structured), time varying perturbation of an asymptotically stable linear time invariant regulator, it is shown that it is possible to further improve these bounds by employing state transformations. Then introducing a quantitative measure called the stability robustness index, a state feedback conrol design algorithm is presented for a general linear regulator problem and then specialized to the case of modal systems as well as matched systems. The extension of the algorithm to stochastic systems with Kalman filter as the state estimator is presented. Finally an algorithm for robust dynamic compensator design is presented using Parameter Optimization (PO) procedure. Applications in a aircraft control and flexible structure control are presented along with a comparison with other existing methods.

  10. NASA-UVA Light Aerospace Alloy and Structures Technology Program (LA2ST). Research on Materials for the High Speed Civil Transport

    NASA Technical Reports Server (NTRS)

    Gangloff, Richard P.; Starke, Edgar A., Jr.; Kelly, Robert G.; Scully, John R.; Stoner, Glenn E.; Wert, John A.

    1997-01-01

    Since 1986, the NASA-Langley Research Center has sponsored the NASA-UVa Light Alloy and Structures Technology (LA2ST) Program at the University of Virginia (UVa). The fundamental objective of the LA2ST program is to conduct interdisciplinary graduate student research on the performance of next generation, light-weight aerospace alloys, composites and thermal gradient structures. The LA2ST program has aimed to product relevant data and basic understanding of material mechanical response, environmental/corrosion behavior, and microstructure; new monolithic and composite alloys; advanced processing methods; measurement and modeling advances; and a pool of educated graduate students for aerospace technologies. The scope of the LA2ST Program is broad. Research areas include: (1) Mechanical and Environmental Degradation Mechanisms in Advanced Light Metals and Composites, (2) Aerospace Materials Science, (3) Mechanics of materials for Aerospace Structures, and (4) Thermal Gradient Structures. A substantial series of semi-annual progress reports issued since 1987 documents the technical objectives, experimental or analytical procedures, and detailed results of graduate student research in these topical areas.

  11. Online Dectection and Modeling of Safety Boundaries for Aerospace Application Using Bayesian Statistics

    NASA Technical Reports Server (NTRS)

    He, Yuning

    2015-01-01

    The behavior of complex aerospace systems is governed by numerous parameters. For safety analysis it is important to understand how the system behaves with respect to these parameter values. In particular, understanding the boundaries between safe and unsafe regions is of major importance. In this paper, we describe a hierarchical Bayesian statistical modeling approach for the online detection and characterization of such boundaries. Our method for classification with active learning uses a particle filter-based model and a boundary-aware metric for best performance. From a library of candidate shapes incorporated with domain expert knowledge, the location and parameters of the boundaries are estimated using advanced Bayesian modeling techniques. The results of our boundary analysis are then provided in a form understandable by the domain expert. We illustrate our approach using a simulation model of a NASA neuro-adaptive flight control system, as well as a system for the detection of separation violations in the terminal airspace.

  12. High-voltage, high-power, solid-state remote power controllers for aerospace applications

    NASA Technical Reports Server (NTRS)

    Sturman, J. C.

    1985-01-01

    Two general types of remote power controller (RPC) that combine the functions of a circuit breaker and a switch were developed for use in direct-current (dc) aerospace systems. Power-switching devices used in these designs are the relatively new gate-turnoff thyristor (GTO) and poweer metal-oxide-semiconductor field-effect transistors (MOSFET). The various RPC's can switch dc voltages to 1200 V and currents to 100 A. Seven different units were constructed and subjected to comprehensive laboratory and thermal vacuum testing. Two of these were dual units that switch both positive and negative voltages simultaneously. The RPC's using MOSFET's have slow turnon and turnoff times to limit voltage spiking from high di/dt. The GTO's have much faster transition times. All RPC's have programmable overload tripout and microsecond tripout for large overloads. The basic circuits developed can be used to build switchgear limited only by the ratings of the switching device used.

  13. Space benefits: The secondary application of aerospace technology in other sectors of the economy

    NASA Technical Reports Server (NTRS)

    1976-01-01

    A 'Benefit Briefing Notebook' was prepared for the NASA Technology Utilization Office to provide accurate, convenient, and integrated resource information on the transfer of aerospace technology to other sectors of the U.S. economy. The contents are divided into three sections: (1) transfer overview, (2) benefit cases, and (3) indexes. The transfer overview section provides a general perspective for technology transfer from NASA to other organizations. In addition to a description of the basic transfer modes, the selection criteria for notebook examples and the kinds of benefit data they contain are also presented. The benefits section is subdivided into nineteen subject areas. Each subsection presents one or more key issues of current interest, with discrete transfer cases related to each key issue. Additional transfer examples relevant to each subject area are then presented. Pertinent transfer data are given at the end of each example.

  14. Numerical simulation of dynamics of brushless dc motors for aerospace and other applications. Volume 2: User's guide to computer EMA model

    NASA Technical Reports Server (NTRS)

    Demerdash, N. A. O.; Nehl, T. W.

    1979-01-01

    A description and user's guide of the computer program developed to simulate the dynamics of an electromechanical actuator for aerospace applications are presented. The effects of the stator phase currents on the permanent magnets of the rotor are examined. The voltage and current waveforms present in the power conditioner network during the motoring, regenerative braking, and plugging modes of operation are presented and discussed.

  15. Reinforcement of poly ether sulphones (PES) with exfoliated graphene oxide for aerospace applications

    NASA Astrophysics Data System (ADS)

    Balasubramanian, K.

    2012-09-01

    Composite materials have been used for aerospace for some time now and have gained virtually 100% acceptance as the materials of choice. Speciality polymers like poly ether sulphones (PES), poly ether ether ketones(PEEK), poly ether imides (PEI) are highly preferred materials as plastic matrix due to their superior temperature performance, excellent wear & friction resistance, excellent dimensional accuracy, high tensile strength, high modulus, precise machinability and chemical resistance. In recent years nanoadditives like single and multiwall carbon nanotubes, graphenes and graphene oxides(GO) are finding huge market potential in aerospace and automobile industries. But manufacture related factors such as particle/ matrix interphases, surface activation, mixing process, particle agglomeration, particle size and shape may lead to different property effects. In this research GO/PES composites were prepared by high shear melt blending technique. GO monolayers were exfoliated from natural graphite flake and dispersed homogeneously in PES matrix for the GO content ranging between 0.5 to 2.0 volume percentage with a high shear twin screw batch mixer. These melt blended nanocomposites were injection moulded for mechanical property validation of tensile strength, flexural modulus and impact resistance. Addition of 0.5 volume percentage of GO enhanced the tensile strength and flexural modulus by 40% and 90% respectively. The results show that addition of GO to PES increase mechanical properties due to the formation of continuous network, good dispersion and strong interfacial interactions. The strong interfacial interactions were accounted for the increase in glass transition temperature. Also there was a significant improvement in the impact resistance of the PES/ GO nanocomposite. The injection moulded samples were tested for stealth performance by measuring the electromagnetic shielding property.

  16. Application of thermal life prediction model to high-temperature aerospace alloys B1900+Hf and Haynes 188

    NASA Technical Reports Server (NTRS)

    Halford, Gary R.; Saltsman, James F.; Verrilli, Michael J.; Arya, Vinod K.

    1990-01-01

    The results of the application of a newly proposed thermomechanical fatigue (TMF) life prediction method to a series of laboratory TMF results on two high-temperature aerospace engine alloys are presented. The method, referred to as TMF/TS-SRP, is based on three relatively recent developments: the total strain version of the method of Strainrange Partitioning (TS-SRP), the bithermal testing technique for characterizing TMF behavior, and advanced viscoplastic constitutive models. The high-temperature data reported in a companion publication are used to evaluate the constants in the model and to provide the TMF verification data to check its accuracy. Predicted lives are in agreement with the experimental lives to within a factor of approximately 2.

  17. Aerospace Dermatology.

    PubMed

    Arora, Gp Capt Sandeep

    2017-01-01

    Evolutionarily, man is a terrestrial mammal, adapted to land. Aviation and now space/microgravity environment, hence, pose new challenges to our physiology. Exposure to these changes affects the human body in acute and chronic settings. Since skin reflects our mental and physical well-being, any change/side effects of this environment shall be detected on the skin. Aerospace industry offers a unique environment with a blend of all possible occupational disorders, encompassing all systems of the body, particularly the skin. Aerospace dermatologists in the near future shall be called upon for their expertise as we continue to push human physiological boundaries with faster and more powerful military aircraft and look to colonize space stations and other planets. Microgravity living shall push dermatology into its next big leap-space, the final frontier. This article discusses the physiological effects of this environment on skin, effect of common dermatoses in aerospace environment, effect of microgravity on skin, and occupational hazards of this industry.

  18. Aerospace Dermatology

    PubMed Central

    Arora, Gp Capt Sandeep

    2017-01-01

    Evolutionarily, man is a terrestrial mammal, adapted to land. Aviation and now space/microgravity environment, hence, pose new challenges to our physiology. Exposure to these changes affects the human body in acute and chronic settings. Since skin reflects our mental and physical well-being, any change/side effects of this environment shall be detected on the skin. Aerospace industry offers a unique environment with a blend of all possible occupational disorders, encompassing all systems of the body, particularly the skin. Aerospace dermatologists in the near future shall be called upon for their expertise as we continue to push human physiological boundaries with faster and more powerful military aircraft and look to colonize space stations and other planets. Microgravity living shall push dermatology into its next big leap-space, the final frontier. This article discusses the physiological effects of this environment on skin, effect of common dermatoses in aerospace environment, effect of microgravity on skin, and occupational hazards of this industry. PMID:28216729

  19. Progress in High Power Density SOFC Material Development for Aerospace Applications

    NASA Technical Reports Server (NTRS)

    Cable, Thomas L.; Sofie, Stephen W.; Setlock, John A.; Misra, Ajay K.

    2004-01-01

    Solid oxide fuel cell (SOFC) systems for aircraft applications require order of magnitude increase in specific power density and long life under aircraft operating conditions. Advanced SOFC materials and fabrication processes are being developed at NASA GRC to increase specific power density and durability of SOFC cell and stack. Initial research efforts for increasing specific power density are directed toward increasing the operating temperature for the SOFC system and reducing the weight of the stack. While significant research is underway to develop anode supported SOFC system operating at temperatures in the range of 650 - 850 C for ground power generation applications, such temperatures may not yield the power densities required for aircraft applications. For electrode-supported cells, SOFC stacks with power densities greater than 1.0 W/sq cm are favorable at temperatures in excess of 900 C. The performance of various commercial and developmental anode supported cells is currently being evaluated in the temperature range of 900 to 1000 C to assess the performance gains and materials reliability. The results from these studies will be presented. Since metal interconnects developed for lower temperature operation are not practical at these high temperatures, advanced perovskite based ceramic interconnects with high electronic conductivity and lower sintering temperatures are being developed. Another option for increasing specific power density of SOFC stacks is to decrease the stack weight. Since the interconnect contributes to a significant portion of the stack weight, considerable weight benefits can be derived by decreasing its thickness. Eliminating the gas channels in the interconnect by engineering the pore structure in both anode and cathode can offer significant reduction in thickness of the ceramic interconnect material. New solid oxide fuel cells are being developed with porous engineered electrode supported structures with a 10 - 20 micron thin

  20. System integration and demonstration of adhesive bonded high temperature aluminum alloys for aerospace structure, phase 2

    NASA Technical Reports Server (NTRS)

    Falcone, Anthony; Laakso, John H.

    1993-01-01

    Adhesive bonding materials and processes were evaluated for assembly of future high-temperature aluminum alloy structural components such as may be used in high-speed civil transport aircraft and space launch vehicles. A number of candidate high-temperature adhesives were selected and screening tests were conducted using single lap shear specimens. The selected adhesives were then used to bond sandwich (titanium core) test specimens, adhesive toughness test specimens, and isothermally aged lap shear specimens. Moderate-to-high lap shear strengths were obtained from bonded high-temperature aluminum and silicon carbide particulate-reinforced (SiC(sub p)) aluminum specimens. Shear strengths typically exceeded 3500 to 4000 lb/in(sup 2) and flatwise tensile strengths exceeded 750 lb/in(sup 2) even at elevated temperatures (300 F) using a bismaleimide adhesive. All faceskin-to-core bonds displayed excellent tear strength. The existing production phosphoric acid anodize surface preparation process developed at Boeing was used, and gave good performance with all of the aluminum and silicon carbide particulate-reinforced aluminum alloys investigated. The results of this program support using bonded assemblies of high-temperature aluminum components in applications where bonding is often used (e.g., secondary structures and tear stoppers).

  1. Vibration fatigue analysis and multi-axial effect in testing of aerospace structures

    NASA Astrophysics Data System (ADS)

    Aykan, Murat; Çelik, Mehmet

    2009-04-01

    The work reported in this paper compared the fatigue damage accumulated under uni-axial loading (a procedure promoted by the vibration testing standards) to that induced by multi-axial loading. The comparison was performed for a helicopter structural element (the flare dispenser bracket of the self-defensive system's Chaff), which is exposed to the particular combination of wide-band random with sinusoidal vibrations, which is characteristic to the helicopter dynamic environment. The evaluation of the fatigue damage induced by these loads requires the calculation or measurement of the structure's dynamic response in terms of stresses or strains, and the application of the appropriate methodology to this response. In this work, dynamic response was calculated in the frequency domain based on the relations between the power spectral density matrixes of the excitations to that of the responses for a linear system. The transfer matrix that relates the excitation to the responses was evaluated numerically. The power spectral densities of the responses evaluated at different locations on the structure were used in the determination of the responses' statistics (the counting of the loading cycles), which, combined with an appropriate physics of failure model (fatigue model), enabled the evaluation of the accumulated fatigue damage. The uni-axial-induced fatigue was evaluated from vibration tests of the kind promoted by military standards (it is assumed that axis-by-axis loading is cumulatively equal to multi-axial loading), and compared to that evaluated by analysis for the multi-axial loading. Also a numerical comparison of the effects of the two kinds of loading was performed. The results showed that the error of uni-axial testing varied for a wide range of parameters. The work led to the conclusion that simultaneous multi-axis vibration testing can improve significantly the laboratory's vibration simulation realism.

  2. Potential and prospective implementation of carbon nanotubes on next generation aircraft and space vehicles: A review of current and expected applications in aerospace sciences

    NASA Astrophysics Data System (ADS)

    Gohardani, Omid; Elola, Maialen Chapartegui; Elizetxea, Cristina

    2014-10-01

    Carbon nanotubes have instigated the interest of many different scientific fields since their authenticated introduction, more than two decades ago. Particularly in aerospace applications, the potential implementations of these advanced materials have been predicted to have a large impact on future aircraft and space vehicles, mainly due to their distinct features, which include superior mechanical, thermal and electrical properties. This article provides the very first consolidated review of the imminent prospects of utilizing carbon nanotubes and nanoparticles in aerospace sciences, based on their recent implementations and predicted future applications. Explicitly, expected carbon nanotube employment in aeronautics and astronautics are identified for commercial aircraft, military aircraft, rotorcraft, unmanned aerial vehicles, satellites, and space launch vehicles. Attention is devoted to future utilization of carbon nanotubes, which may comprise hydrogen storage encapsulation, composite material implementation, lightning protection for aircraft, aircraft icing mitigation, reduced weight of airframes/satellites, and alleviation of challenges related to future space launch. This study further sheds light onto recent actualized implementations of carbon nanotubes in aerospace applications, as well as current and prospective challenges related to their usage in aerospace sciences, encompassing health and safety hazards, large scale manufacturing, achievement of optimum properties, recycling, and environmental impacts.

  3. Chromatography - mass spectrometry in aerospace industry

    NASA Astrophysics Data System (ADS)

    Buryak, A. K.; Serdyuk, T. M.

    2013-01-01

    The applications of chromatography - mass spectrometry in aerospace industry are considered. The primary attention is devoted to the development of physicochemical grounds of the use of various chromatography - mass spectrometry procedures to solve topical problems of this industry. Various methods for investigation of the composition of rocket fuels, surfaces of structural materials and environmental media affected by aerospace activities are compared. The application of chromatography - mass spectrometry for the development and evaluation of processes for decontaminations of equipment, industrial wastes and soils from rocket fuel components is substantiated. The bibliography includes 135 references.

  4. Applied breath analysis: an overview of the challenges and opportunities in developing and testing sensor technology for human health monitoring in aerospace and clinical applications.

    PubMed

    Hunter, Gary W; Dweik, Raed A

    2008-09-01

    The aerospace industry requires the development of a range of chemical sensor technologies for such applications as leak detection, emission monitoring, fuel leak detection, environmental monitoring, and fire detection. A family of chemical sensors are being developed based on micromachining and microfabrication technology to fabricate microsensors with minimal size, weight, and power consumption, and the use of nanomaterials and structures to develop sensors with improved stability combined with higher sensitivity. However, individual sensors are limited in the amount of information that they can provide in environments that contain multiple chemical species. Thus, sensor arrays are being developed to address detection needs in such multi-species environments. These technologies and technical approaches have direct relevance to breath monitoring for clinical applications. This paper gives an overview of developing cutting-edge sensor technology and possible barriers to new technology implementation. This includes lessons learned from previous microsensor development, recent work in development of a breath monitoring system, and future directions in the implementation of cutting edge sensor technology. Clinical applications and the potential impact to the biomedical field of miniaturized smart gas sensor technology are discussed.

  5. Technical features and criteria in designing fiber-reinforced composite materials: from the aerospace and aeronautical field to biomedical applications.

    PubMed

    Gloria, Antonio; Ronca, Dante; Russo, Teresa; D'Amora, Ugo; Chierchia, Marianna; De Santis, Roberto; Nicolais, Luigi; Ambrosio, Luigi

    2011-01-01

    Polymer-based composite materials are ideal for applications where high stiffness-to-weight and strength-to-weight ratios are required. From aerospace and aeronautical field to biomedical applications, fiber-reinforced polymers have replaced metals, thus emerging as an interesting alternative. As widely reported, the mechanical behavior of the composite materials involves investigation on micro- and macro-scale, taking into consideration micromechanics, macromechanics and lamination theory. Clinical situations often require repairing connective tissues and the use of composite materials may be suitable for these applications because of the possibility to design tissue substitutes or implants with the required mechanical properties. Accordingly, this review aims at stressing the importance of fiber-reinforced composite materials to make advanced and biomimetic prostheses with tailored mechanical properties, starting from the basic principle design, technologies, and a brief overview of composites applications in several fields. Fiber-reinforced composite materials for artificial tendons, ligaments, and intervertebral discs, as well as for hip stems and mandible models will be reviewed, highlighting the possibility to mimic the mechanical properties of the soft and hard tissues that they replace.

  6. Adhesives for Aerospace

    NASA Technical Reports Server (NTRS)

    Meade, L. E.

    1985-01-01

    The industry is hereby challenged to integrate adhesive technology with the total structure requirements in light of today's drive into automation/mechanization. The state of the art of adhesive technology is fairly well meeting the needs of the structural designers, the processing engineer, and the inspector, each on an individual basis. The total integration of these needs into the factory of the future is the next collective hurdle to be achieved. Improved processing parameters to fit the needs of automation/mechanization will necessitate some changes in the adhesive forms, formulations, and chemistries. Adhesives have, for the most part, kept up with the needs of the aerospace industry, normally leading the rest of the industry in developments. The wants of the aerospace industry still present a challenge to encompass all elements, achieving a totally integrated joined and sealed structural system. Better toughness with hot-wet strength improvements is desired. Lower cure temperatures, longer out times, and improved corrosion inhibition are desired.

  7. A review of properties and potential aerospace applications of electrically conducting polymers

    NASA Technical Reports Server (NTRS)

    Meador, Mary Ann B.; Gaier, James R.; Good, Brian S.; Sharp, G. Richard; Meador, Michael A.

    1990-01-01

    An overview of current research in conducting polymers is presented. Emphasis is placed on development of materials useful for aeronautic and space applications. Research on organic conducting polymers began in the early 1970s with the discovery of polyacetylene. Since then, many polymers which share structural characteristics with polyacetylene have been prepared which conduct electricity, especially when they are doped with suitable agents. Problems with environmental instability, difficult processing, poor mechanical properties and high cost have slowed the development of conducting polymers. However, practical use of these materials is imminent, based on recent refinements in understanding how polymers conduct, more systematic approaches to the development of new materials, and significant improvements in both the processing and properties.

  8. Monitoring of bolted joints using piezoelectric active-sensing for aerospace applications

    SciTech Connect

    Park, Gyuhae; Farrar, Charles R; Park, Chan - Yik; Jun, Seung - Moon

    2010-01-01

    This paper is a report of an initial investigation into tracking and monitoring the integrity of bolted joints using piezoelectric active-sensors. The target application of this study is a fitting lug assembly of unmanned aerial vehicles (UAVs), where a composite wing is mounted to a UAV fuselage. The SHM methods deployed in this study are impedance-based SHM techniques, time-series analysis, and high-frequency response functions measured by piezoelectric active-sensors. Different types of simulated damage are introduced into the structure, and the capability of each technique is examined and compared. Additional considerations encountered in this initial investigation are made to guide further thorough research required for the successful field deployment of this technology.

  9. Mass spectrometry of aerospace materials

    NASA Technical Reports Server (NTRS)

    Colony, J. A.

    1976-01-01

    Mass spectrometry is used for chemical analysis of aerospace materials and contaminants. Years of analytical aerospace experience have resulted in the development of specialized techniques of sampling and analysis which are required in order to optimize results. This work has resulted in the evolution of a hybrid method of indexing mass spectra which include both the largest peaks and the structurally significant peaks in a concise format. With this system, a library of mass spectra of aerospace materials was assembled, including the materials responsible for 80 to 90 percent of the contamination problems at Goddard Space Flight Center during the past several years.

  10. Temperature and heat flux measurements: Challenges for high temperature aerospace application

    NASA Technical Reports Server (NTRS)

    Neumann, Richard D.

    1992-01-01

    The measurement of high temperatures and the influence of heat transfer data is not strictly a problem of either the high temperatures involved or the level of the heating rates to be measured at those high temperatures. It is a problem of duration during which measurements are made and the nature of the materials in which the measurements are made. Thermal measurement techniques for each application must respect and work with the unique features of that application. Six challenges in the development of measurement technology are discussed: (1) to capture the character and localized peak values within highly nonuniform heating regions; (2) to manage large volumes of thermal instrumentation in order to efficiently derive critical information; (3) to accommodate thermal sensors into practical flight structures; (4) to broaden the capabilities of thermal survey techniques to replace discrete gages in flight and on the ground; (5) to provide supporting instrumentation conduits which connect the measurement points to the thermally controlled data acquisition system; and (6) to develop a class of 'vehicle tending' thermal sensors to assure the integrity of flight vehicles in an efficient manner.

  11. Aerospace Education - An Overview

    ERIC Educational Resources Information Center

    Journal of Aerospace Education, 1975

    1975-01-01

    Discusses the surge of interest throughout the country in aerospace education and discusses what aerospace education is, the implications in career education and the relevance of aerospace education in the curriculum. (BR)

  12. Basic Aerospace Education Library

    ERIC Educational Resources Information Center

    Journal of Aerospace Education, 1975

    1975-01-01

    Lists the most significant resource items on aerospace education which are presently available. Includes source books, bibliographies, directories, encyclopedias, dictionaries, audiovisuals, curriculum/planning guides, aerospace statistics, aerospace education statistics and newsletters. (BR)

  13. Trajectory optimization and guidance law development for national aerospace plane applications

    NASA Technical Reports Server (NTRS)

    Calise, A. J.; Corban, J. E.; Flandro, G. A.

    1988-01-01

    The problem of onboard trajectory optimization for an airbreathing, single-stage-to-orbit vehicle is examined. A simple model representative of the aerospace plane concept, including a dual-mode propulsion system composed of scramjet and rocket engines, is presented. Consideration is restricted to hypersonic flight within the atmosphere. An energy state approximation is used in a four-state model for flight of a point mass in a vertical plane. Trajectory constraints, including those of dynamic pressure and aerodynamic heating, are initially ignored. Singular perturbation methods are applied in solving the optimal control problem of minimum fuel climb. The resulting reduced solution for the energy state dynamics provides an optimal altitude profile dependent on energy level and control for rocket thrust. A boundary-layer analysis produces an approximate lift control solution in feedback form and accounts for altitude and flight path angle dynamics. The reduced solution optimal climb path is presented for the unconstrained case and the case for which a maximum dynamic pressure constraint is enforced.

  14. Slush Hydrogen (SLH2) technology development for application to the National Aerospace Plane (NASP)

    NASA Technical Reports Server (NTRS)

    Dewitt, Richard L.; Hardy, Terry L.; Whalen, Margaret V.; Richter, G. Paul

    1989-01-01

    The National Aerospace Plane (NASP) program is giving us the opportunity to reach new unique answers in a number of engineering categories. The answers are considered enhancing technology or enabling technology. Airframe materials and densified propellants are examples of enabling technology. The National Aeronautics and Space Administration's Lewis Research Center has the task of providing the technology data which will be used as the basis to decide if slush hydrogen (SLH2) will be the fuel of choice for the NASP. The objectives of this NASA Lewis program are: (1) to provide, where possible, verified numerical models of fluid production, storage, transfer, and feed systems, and (2) to provide verified design criteria for other engineered aspects of SLH2 systems germane to a NASP. This program is a multiyear multimillion dollar effort. The present pursuit of the above listed objectives is multidimensional, covers a range of problem areas, works these to different levels of depth, and takes advantage of the resources available in private industry, academia, and the U.S. Government. The NASA Lewis overall program plan is summarized. The initial implementation of the plan will be unfolded and the present level of efforts in each of the resource areas will be discussed. Results already in hand will be pointed out. A description of additionally planned near-term experimental and analytical work is described.

  15. Progress of Ongoing NASA Lithium-Ion Cell Verification Testing for Aerospace Applications

    NASA Technical Reports Server (NTRS)

    McKissock, Barbara I.; Manzo, Michelle A.; Miller, Thomas B.; Reid, Concha M.; Bennett, William R.; Gemeiner, Russel

    2008-01-01

    A Lithium-ion Verification and Validation Program with the purpose to assess the capabilities of current aerospace lithium-ion (Li-ion) battery cells to perform in a low-earth-orbit (LEO) regime was initiated in 2002. This program involves extensive characterization and LEO life testing at ten different combinations of depth-of-discharge, temperature, and end-of-charge voltage. The test conditions selected for the life tests are defined as part of a statistically designed test matrix developed to determine the effects of operating conditions on performance and life of Li-ion cells. Results will be used to model and predict cell performance and degradation as a function of test operating conditions. Testing is being performed at the Naval Surface Warfare Center/Crane Division in Crane, Indiana. Testing was initiated in September 2004 with 40 Ah cells from Saft and 30 Ah cells from Lithion. The test program has been expanded with the addition of modules composed of 18650 cells from ABSL Power Solutions in April 2006 and the addition of 50 Ah cells from Mine Safety Appliances Co. (MSA) in June 2006. Preliminary results showing the average voltage and average available discharge capacity for the Saft and Lithion packs at the test conditions versus cycles are presented.

  16. Aerospace gerontology

    NASA Technical Reports Server (NTRS)

    Comfort, A.

    1982-01-01

    The relevancy of gerontology and geriatrics to the discipline of aerospace medicine is examined. It is noted that since the shuttle program gives the facility to fly passengers, including specially qualified older persons, it is essential to examine response to acceleration, weightlessness, and re-entry over the whole adult lifespan, not only its second quartile. The physiological responses of the older person to weightlessness and the return to Earth gravity are reviewed. The importance of the use of the weightless environment to solve critical problems in the fields of fundamental gerontology and geriatrics is also stressed.

  17. AI aerospace components

    NASA Technical Reports Server (NTRS)

    Heindel, Troy A.; Murphy, Terri B.; Rasmussen, Arthur N.; Mcfarland, Robert Z.; Montgomery, Ronnie E.; Pohle, George E.; Heard, Astrid E.; Atkinson, David J.; Wedlake, William E.; Anderson, John M.

    1991-01-01

    An evaluation is made of the application of novel, AI-capabilities-related technologies to aerospace systems. Attention is given to expert-system shells for Space Shuttle Orbiter mission control, manpower and processing cost reductions at the NASA Kennedy Space Center's 'firing rooms' for liftoff monitoring, the automation of planetary exploration systems such as semiautonomous mobile robots, and AI for battlefield staff-related functions.

  18. Applications of structural optimization methods to fixed-wing aircraft and spacecraft in the 1980s

    NASA Technical Reports Server (NTRS)

    Miura, Hirokazu; Neill, Douglas J.

    1992-01-01

    This report is the summary of a technical survey on the applications of structural optimization in the U.S. aerospace industry through the 1980s. Since applications to rotary wing aircraft will be covered by other literature, applications to fixed-wing aircraft and spacecraft were considered. It became clear that very significant progress has been made during this decade, indicating this technology is about to become one of the practical tools in computer aided structural design.

  19. CSM Testbed Development and Large-Scale Structural Applications

    NASA Technical Reports Server (NTRS)

    Knight, Norman F., Jr.; Gillian, R. E.; Mccleary, Susan L.; Lotts, C. G.; Poole, E. L.; Overman, A. L.; Macy, S. C.

    1989-01-01

    A research activity called Computational Structural Mechanics (CSM) conducted at the NASA Langley Research Center is described. This activity is developing advanced structural analysis and computational methods that exploit high-performance computers. Methods are developed in the framework of the CSM Testbed software system and applied to representative complex structural analysis problems from the aerospace industry. An overview of the CSM Testbed methods development environment is presented and some new numerical methods developed on a CRAY-2 are described. Selected application studies performed on the NAS CRAY-2 are also summarized.

  20. Recent NASA progress in composites. [application to spacecraft and aircraft structures

    NASA Technical Reports Server (NTRS)

    Heldenfels, R. R.

    1975-01-01

    The application of composites in aerospace vehicle structures is reviewed. Research and technology program results and specific applications to space vehicles, aircraft engines, and aircraft and helicopter structures are discussed in detail. Particular emphasis is given to flight service evaluation programs that are or will be accumulating substantial experience with secondary and primary structural components on military and commercial aircraft to increase confidence in their use.

  1. An Aerospace Nation

    DTIC Science & Technology

    2016-05-25

    aircraft order share of Boeing or Air - bus in recent years.24 America’s leadership in the high-technology sector is also faltering and, if not corrected...Executive Order 9781, establishing the Air Coordinating Commit- tee, with the mission to “examine aviation problems and development affecting more...robotics, drones, information technologies, energy research, and aerospace design. Establish a New Air and Space Structure Like its predecessor

  2. Aerothermal and aeroelastic response prediction of aerospace structures in high-speed flows using direct numerical simulation

    NASA Astrophysics Data System (ADS)

    Ostoich, Christopher Mark

    Future high-speed air vehicles will be lightweight, flexible, and reusable. Ve- hicles fitting this description are subject to severe thermal and fluid dynamic loading from multiple sources such as aerothermal heating, propulsion sys- tem exhaust, and high dynamic pressures. The combination of low-margin design requirements and extreme environmental conditions emphasizes the occurrence of fluid-thermal-structural coupling. Numerous attempts to field such vehicles have been unsuccessful over the past half-century due par- tially to the inability of traditional design and analysis practices to predict the structural response in this flight regime. In this thesis, a high-fidelity computational approach is used to examine the fluid-structural response of aerospace structures in high-speed flows. The method is applied to two cases: one involving a fluid-thermal interaction problem in a hypersonic flow and the other a fluid-structure interaction study involving a turbulent boundary layer and a compliant panel. The coupled fluid-thermal investigation features a nominally rigid alu- minum spherical dome fixed to a ceramic panel holder placed in a Mach 6.59 laminar boundary layer. The problem was originally studied by Glass and Hunt in a 1988 wind tunnel experiment in the NASA Langley 8-Foot High Temperature Tunnel and is motivated by thermally bowed body panels designed for the National Aerospace Plane. In this work, the compressible Navier-Stokes equations for a thermally perfect gas and the transient heat equation in the structure are solved simultaneously using two high-fidelity solvers coupled at the solid-fluid interface. Predicted surface heat fluxes are within 10% of the measured values in the dome interior with greater differ- ences found near the dome edges where uncertainties concerning the exper- imental model's construction likely influence the thermal dynamics. On the flat panel holder, the local surface heat fluxes approach those on the wind- ward dome face

  3. Towards an aerogel-based coating for aerospace applications: reconstituting aerogel particles via spray drying

    NASA Astrophysics Data System (ADS)

    Bheekhun, N.; Abu Talib, A. R.; Mustapha, S.; Ibrahim, R.; Hassan, M. R.

    2016-10-01

    Silica aerogel is an ultralight and highly porous nano-structured ceramic with its thermal conductivity being the lowest than any solids. Although aerogels possess fascinating physical properties, innovative solutions to tackle today's problems were limited due to their relative high manufacturing cost in comparison to conventional materials. Recently, some producers have brought forward quality aerogels at competitive costs, and thereby opening a panoply of applied research in this field. In this paper, the feasibility of spray-drying silica aerogel to tailor its granulometric property is studied for thermal spraying, a novel application of aerogels that is never tried before in the academic arena. Aerogel-based slurries with yttria stabilised zirconia as a secondary ceramic were prepared and spray-dried according to modified T aguchi experimental design in order to appreciate the effect of both the slurry formulation and drying conditions such as the solid content, the ratio of yttria stabilised zirconia:aerogel added, the amount of dispersant and binder, inlet temperature, atomisation pressure and feeding rate on the median particle size of the resulting spray-dried powder. The latter was found to be affected by all the aforementioned independent variables at different degree of significance and inclination. Based on the derived relationships, an optimised condition to achieve maximum median particle size was then predicted.

  4. NASA's activities in the conservation of strategic aerospace materials

    NASA Technical Reports Server (NTRS)

    Stephens, J. R.

    1980-01-01

    The United States imports 50-100 percent of certain metals critical to the aerospace industry, namely, cobalt, columbium, chromium, and tantalum. In an effort to reduce this dependence on foreign sources, NASA is planning a program called Conservation of Strategic Aerospace Materials (COSAM), which will provide technology minimizing strategic metal content in the components of aerospace structures such as aircraft engines. With a proposed starting date of October 1981, the program will consist of strategic element substitution, process technology development, and alternate materials research. NASA's two-fold pre-COSAM studies center on, first, substitution research involving nickel-base and cobalt-base superalloys (Waspaloy, Udimet-700, MAE-M247, Rene 150, HA-188) used in turbine disks, low-pressure blades, turbine blades, and combustors; and, second, alternate materials research devoted initially to investigating possible structural applications of the intermetallic alloys nickel aluminide and iron aluminide.

  5. The Aerospace Age. Aerospace Education I.

    ERIC Educational Resources Information Center

    Smith, J. C.

    This book is written for use only in the Air Force ROTC program and cannot be purchased on the open market. The book describes the historical development of aerospace industry. The first chapter contains a brief review of the aerospace environment and the nature of technological changes brought by the aerospace revolution. The following chapter…

  6. Resilient and Corrosion-Proof Rolling Element Bearings Made from Superelastic Ni-Ti Alloys for Aerospace Mechanism Applications

    NASA Technical Reports Server (NTRS)

    DellaCorte, Christopher; Noebe, Ronald D.; Stanford, Malcolm; Padula, Santo A.

    2011-01-01

    Mechanical components (bearings, gears, mechanisms) typically utilize hard materials to minimize wear and attain long life. In such components, heavily loaded contact points (e.g., meshing gear teeth, bearing ball-raceway contacts) experience high contact stresses. The combination of high hardness, heavy loads and high elastic modulus often leads to damaging contact stress. In addition, mechanical component materials, such as tool steel or silicon nitride exhibit limited recoverable strain (typically less than 1 percent). These material attributes can lead to Brinell damage (e.g., denting) particularly during transient overload events such as shock impacts that occur during the launching of space vehicles or the landing of aircraft. In this paper, a superelastic alloy, 60NiTi, is considered for rolling element bearing applications. A series of Rockwell and Brinell hardness, compressive strength, fatigue and tribology tests are conducted and reported. The combination of high hardness, moderate elastic modulus, large recoverable strain, low density, and intrinsic corrosion immunity provide a path to bearings largely impervious to shock load damage. It is anticipated that bearings and components made from alloys with such attributes can alleviate many problems encountered in advanced aerospace applications.

  7. Development of Advanced Verification and Validation Procedures and Tools for the Certification of Learning Systems in Aerospace Applications

    NASA Technical Reports Server (NTRS)

    Jacklin, Stephen; Schumann, Johann; Gupta, Pramod; Richard, Michael; Guenther, Kurt; Soares, Fola

    2005-01-01

    Adaptive control technologies that incorporate learning algorithms have been proposed to enable automatic flight control and vehicle recovery, autonomous flight, and to maintain vehicle performance in the face of unknown, changing, or poorly defined operating environments. In order for adaptive control systems to be used in safety-critical aerospace applications, they must be proven to be highly safe and reliable. Rigorous methods for adaptive software verification and validation must be developed to ensure that control system software failures will not occur. Of central importance in this regard is the need to establish reliable methods that guarantee convergent learning, rapid convergence (learning) rate, and algorithm stability. This paper presents the major problems of adaptive control systems that use learning to improve performance. The paper then presents the major procedures and tools presently developed or currently being developed to enable the verification, validation, and ultimate certification of these adaptive control systems. These technologies include the application of automated program analysis methods, techniques to improve the learning process, analytical methods to verify stability, methods to automatically synthesize code, simulation and test methods, and tools to provide on-line software assurance.

  8. Analysis of Light Emitting Diode Technology for Aerospace Suitability in Human Space Flight Applications

    NASA Astrophysics Data System (ADS)

    Treichel, Todd H.

    Commercial space designers are required to manage space flight designs in accordance with parts selections made from qualified parts listings approved by Department of Defense and NASA agencies for reliability and safety. The research problem was a government and private aerospace industry problem involving how LEDs cannot replace existing fluorescent lighting in manned space flight vehicles until such technology meets DOD and NASA requirements for reliability and safety, and effects on astronaut cognition and health. The purpose of this quantitative experimental study was to determine to what extent commercial LEDs can suitably meet NASA requirements for manufacturer reliability, color reliability, robustness to environmental test requirements, and degradation effects from operational power, while providing comfortable ambient light free of eyestrain to astronauts in lieu of current fluorescent lighting. A fractional factorial experiment tested white and blue LEDs for NASA required space flight environmental stress testing and applied operating current. The second phase of the study used a randomized block design, to test human factor effects of LEDs and a qualified ISS fluorescent for retinal fatigue and eye strain. Eighteen human subjects were recruited from university student members of the American Institute of Aeronautics and Astronautics. Findings for Phase 1 testing showed that commercial LEDs met all DOD and NASA requirements for manufacturer reliability, color reliability, robustness to environmental requirements, and degradation effects from operational power. Findings showed statistical significance for LED color and operational power variables but degraded light output levels did not fall below the industry recognized <70%. Findings from Phase 2 human factors testing showed no statistically significant evidence that the NASA approved ISS fluorescent lights or blue or white LEDs caused fatigue, eye strain and/or headache, when study participants perform

  9. NASA-UVa light aerospace alloy and structure technology program supplement: Aluminum-based materials for high speed aircraft

    NASA Technical Reports Server (NTRS)

    Starke, E. A., Jr.

    1993-01-01

    This report on the NASA-UVa Light Aerospace Alloy and Structure Technology Program Supplement: Aluminum-Based Materials for High Speed Aircraft covers the period from January 1, 1992 to June 30, 1992. The objective of the research is to develop aluminum alloys and aluminum matrix composites for the airframe which can efficiently perform in the HSCT environment for periods as long as 60,000 hours (certification for 120,000 hours) and, at the same time, meet the cost and weight requirements for an economically viable aircraft. Current industry baselines focus on flight at Mach 2.4. The research covers four major materials systems: (1) ingot metallurgy 2XXX, 6XXX, and 8XXX alloys, (2) powder metallurgy 2XXX alloys, (3) rapidly solidified, dispersion strengthened Al-Fe-X alloys, and (4) discontinuously reinforced metal matrix composites. There are ten major tasks in the program which also include evaluation and trade-off studies by Boeing and Douglas aircraft companies.

  10. Aerospace Structures Technology Damping Design Guide. Volume 3. Damping Material Data

    DTIC Science & Technology

    1985-12-01

    1.1 DAMPING MATERIAL PROPERTIES 1 3 1.2 THE STANDARIZED MATERIAL DATA I 1.2.1 Nomogram Cover Sheet 3 ’ 1.2.2 The Reduced Nomogram 4 1.2.3 Reading...MATERIALS 6 2 DAMPING MATERIAL PROPERTY DATA 14 3 STRUCTURAL EPOXIES AND OTHER MATERIALS 469 3.1 STRUCTURAL EPOXIES 469 3.2 STRUCTURAL PLASTICS 477 3.3...Data Listing II 6 Temperature Shift Function and Its Properties 12 7 Typical TCA Plot 13 8 Quick Reference Chart for Damping Materials 15 9 Damping vs

  11. Stochastic Models of Composite Mechanics in the Problems of Designing Structural Elements in Aerospace Engineering

    NASA Astrophysics Data System (ADS)

    Sokolkin, Yu. V.; Makarova, E. Yu.

    2002-09-01

    The present-day trends and development prospects of stochastic averaging methods in composite mechanics are analyzed. The following methods are considered: the traditional one (the medium of comparison is homogeneous), the method of periodic components (the medium of comparison has a regular structure), the numerical method of local approximation with regard for the short-range order in the arrangement and interaction of inhomogeneities, and a synthesis of the periodic-component and local-approximation methods. A detailed procedure is presented for calculating the functionals of second, third, and higher orders of the stochastic problem. The results obtained are used for evaluating, in an explicit form, corrections to the effective elastic moduli found for quasi-isotropic and unidirectional fiber composites by the traditional averaging method and the method of periodic components. Analytical formulas for the second-order moment functions of structural stresses and strains are derived. It is shown that the fields of structural stresses and strains are locally ergodic. A new multilevel approach is proposed for designing composites, which takes into account the effect of structurally technological factors. Thus, unidirectional fiber composites are calculated by a two-level model, layered structures - by a three-level model, and carbon-carbon structures - by a five-level model. A stage-by-stage solution procedure is suggested for the boundary-value problem of micromechanics of composites. For a wide class of composites, the effective elastic moduli are calculated and the strength surfaces are constructed.

  12. Noncertainty equivalent nonlinear adaptive control and its applications to mechanical and aerospace systems

    NASA Astrophysics Data System (ADS)

    Seo, Dong Eun

    Adaptive control has long focused on establishing stable adaptive control methods for various nonlinear systems. Existing methods are mostly based on the certainty equivalence principle which states that the controller structure developed in the deterministic case (without uncertain system parameters) can be used for controlling the uncertain system along by adopting a carefully determined parameter estimator. Thus, the overall performance of the regulating/tracking control depends on the performance of the parameter estimator, which often results in the poor closed-loop performance compared with the deterministic control because the parameter estimate can exhibit wide variations compared to their true values in general. In this dissertation, we introduce a new adaptive control method for nonlinear systems where unknown parameters are estimated to within an attracting manifold and the proposed control method always asymptotically recovers the closed-loop error dynamics of the deterministic case control system. Thus, the overall performance of this new adaptive control method is comparable to that of the deterministic control method, something that is usually impossible to obtain with the certainty equivalent control method. We apply the noncertainty equivalent adaptive control to study application arising in the n degree of freedom (DOF) robot control problem and spacecraft attitude control. Especially, in the context of the spacecraft attitude control problem, we developed a new attitude observer that also utilizes an attracting manifold, while ensuring that the estimated attitude matrix confirms at all instants to the special group of rotation matrices SO(3). As a result, we demonstrate for the first time a separation property of the nonlinear attitude control problem in terms of the observer/controller based closed-loop system. For both the robotic and spacecraft attitude control problems, detailed derivations for the controller design and accompanying stability

  13. Chemical, mechanical and antibacterial properties of silver nanocluster/silica composite coated textiles for safety systems and aerospace applications

    NASA Astrophysics Data System (ADS)

    Ferraris, S.; Perero, S.; Miola, M.; Vernè, E.; Rosiello, A.; Ferrazzo, V.; Valletta, G.; Sanchez, J.; Ohrlander, M.; Tjörnhammar, S.; Fokine, M.; Laurell, F.; Blomberg, E.; Skoglund, S.; Odnevall Wallinder, I.; Ferraris, M.

    2014-10-01

    This work describes the chemical, mechanical and antibacterial properties of a novel silver nanocluster/silica composite coating, obtained by sputtering, on textiles for use in nuclear bacteriological and chemical (NBC) protection suites and for aerospace applications. The properties of the coated textiles were analyzed in terms of surface morphology, silver concentration and silver release in artificial sweat and synthetic tap water, respectively. No release of silver nanoparticles was observed at given conditions. The water repellency, permeability, flammability and mechanical resistance of the textiles before and after sputtering demonstrated that the textile properties were not negatively affected by the coating. The antibacterial effect was evaluated at different experimental conditions using a standard bacterial strain of Staphylococcus aureus and compared with the behavior of uncoated textiles. The coating process conferred all textiles a good antibacterial activity. Optimal deposition conditions were elaborated to obtain sufficient antibacterial action without altering the aesthetical appearance of the textiles. The antibacterial coating retained its antibacterial activity after one cycle in a washing machine only for the Nylon based textile.

  14. Survey - Applications of structural optimization methods to fixed wing aircraft and spacecraft

    NASA Technical Reports Server (NTRS)

    Miura, Hirokazu; Neill, Douglas J.

    1992-01-01

    Results of a technical survey of the practical applications of structural optimization methods in the U.S. aerospace industry through 1980s are summarized. One of the most important developments in the 80s is the more widespread acceptance of structural optimization as one of the design tools that support practical structural design. Another significant advance is the development of large software tools for production applications. Attention is also given to the tailoring of the computerized design process to the specific environment of each company. The two most important aspects of this tailoring are seamless and easy-to-use incorporation of structural optimization in the overall aerospace design/production process and multidisciplinary integration aimed at ultimate performance optimization of the final product. Some specific applications discussed include the X-29 forward swept wing demonstrator aircraft, composite wing and vertical tail program, fighter wing redesign evaluations, high speed aircraft design, and space structures.

  15. Analysis and Sizing for Transient Thermal Heating of Insulated Aerospace Vehicle Structures

    NASA Technical Reports Server (NTRS)

    Blosser, Max L.

    2012-01-01

    An analytical solution was derived for the transient response of an insulated structure subjected to a simplified heat pulse. The solution is solely a function of two nondimensional parameters. Simpler functions of these two parameters were developed to approximate the maximum structural temperature over a wide range of parameter values. Techniques were developed to choose constant, effective thermal properties to represent the relevant temperature and pressure-dependent properties for the insulator and structure. A technique was also developed to map a time-varying surface temperature history to an equivalent square heat pulse. Equations were also developed for the minimum mass required to maintain the inner, unheated surface below a specified temperature. In the course of the derivation, two figures of merit were identified. Required insulation masses calculated using the approximate equation were shown to typically agree with finite element results within 10%-20% over the relevant range of parameters studied.

  16. High frequency guided waves for hidden fatigue crack growth monitoring in multi-layer aerospace structures

    NASA Astrophysics Data System (ADS)

    Chan, Henry; Fromme, Paul

    2015-03-01

    Varying loading conditions of aircraft structures result in stress concentration at fastener holes, where multi-layered components are connected, possibly leading to the development of fatigue cracks. High frequency guided waves propagating along the structure allow for the non-destructive testing of such components, e.g., aircraft wings. However, the sensitivity for the detection of small, potentially hidden, fatigue cracks has to be ascertained. The type of multi-layered model structure investigated consists of two adhesively bonded aluminium plate-strips. Fatigue experiments were carried out. The sensitivity of the high frequency guided wave modes to monitor fatigue crack growth at a fastener hole during cyclic loading was investigated, using both standard pulse-echo equipment and laser interferometry. The sensitivity and repeatability of the measurements were ascertained, having the potential for fatigue crack growth monitoring at critical and difficult to access fastener locations from a stand-off distance.

  17. Filling the expertise gap. [aeroservoelasticity,structures,stability and control design of aerospace vehicles

    NASA Technical Reports Server (NTRS)

    Abel, Irving

    1988-01-01

    Aeroelasticity, structures, and stability-and-control specialists can work in concerted fashion during the early design phases of future aircraft to achieve active control of naturally unstable configurations. In order to take full advantage of active control, attention must be given by designers to control-law synthesis, and to tools for the efficient synthesis and analysis of complex flexible-aircraft control systems. Analysts must consider interfaces among unsteady aerodynamics, structures, and control theory, as explored by the theory of analytic continuation for unsteady aerodynamics.

  18. Large-Deformation Displacement Transfer Functions for Shape Predictions of Highly Flexible Slender Aerospace Structures

    NASA Technical Reports Server (NTRS)

    Ko, William L.; Fleischer, Van Tran

    2013-01-01

    Large deformation displacement transfer functions were formulated for deformed shape predictions of highly flexible slender structures like aircraft wings. In the formulation, the embedded beam (depth wise cross section of structure along the surface strain sensing line) was first evenly discretized into multiple small domains, with surface strain sensing stations located at the domain junctures. Thus, the surface strain (bending strains) variation within each domain could be expressed with linear of nonlinear function. Such piecewise approach enabled piecewise integrations of the embedded beam curvature equations [classical (Eulerian), physical (Lagrangian), and shifted curvature equations] to yield closed form slope and deflection equations in recursive forms.

  19. Research on optimal control, stabilization and computational algorithms for aerospace applications

    NASA Technical Reports Server (NTRS)

    Athans, M.

    1984-01-01

    The research carried out in the areas of optimal control and estimation theory and its applications under this grant is reviewed. A listing of the 257 publications that document the research results is presented.

  20. Aerospace Applications of Weibull and Monte Carlo Simulation with Importance Sampling

    NASA Technical Reports Server (NTRS)

    Bavuso, Salvatore J.

    1998-01-01

    Recent developments in reliability modeling and computer technology have made it practical to use the Weibull time to failure distribution to model the system reliability of complex fault-tolerant computer-based systems. These system models are becoming increasingly popular in space systems applications as a result of mounting data that support the decreasing Weibull failure distribution and the expectation of increased system reliability. This presentation introduces the new reliability modeling developments and demonstrates their application to a novel space system application. The application is a proposed guidance, navigation, and control (GN&C) system for use in a long duration manned spacecraft for a possible Mars mission. Comparisons to the constant failure rate model are presented and the ramifications of doing so are discussed.