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Sample records for 62-pound steel bolts

  1. Proof Testing Of Stainless-Steel Bolts

    NASA Technical Reports Server (NTRS)

    Hsieh, Cheng H.; Hendrickson, James A.; Bamford, Robert M.

    1992-01-01

    Report describes study of development of method for nondestructive proof testing of bolts made of A286 stainless steel. Based on concept that the higher load bolt survives, the smaller the largest flaw and, therefore, the longer its fatigue life after test. Calculations and experiments increase confidence in nondestructive proof tests.

  2. Guidelines for structural bolting in accordance with the AISC (American Institute of Steel Construction) eighth edition manual of steel construction''

    SciTech Connect

    Western, J.L.; Johns, D.M.

    1990-05-11

    This paper specifies the usage of structural bolts in terms of their design, selection and application, in accordance with the American Institute of Steel Construction (AISC) Eighth Edition. Manual of Steel Construction.'' 1 tab.

  3. Bolting applications

    SciTech Connect

    Czajkowski, C J

    1984-05-01

    An investigation of bolting practices specific to the nuclear industry was performed. The report covered a large spectrum of topics e.g. bolts embedded in concrete, specifications, inspection of bolting, both at receipt and inservice. Plots of preload versus yield strength for different bolting materials in different environments are presented as well as information relative to the stress corrosion cracking resistance of the more recent reactor internals bolting materials A286 and Inconel X-750. Part of the report contains input by Standard Pressed Steel Inc. (a bolting consultant) relative to bolting standards, cottering methods and potential areas for bolting improvement.

  4. Shear fracture of jointed steel plates of bolted joints under impact load

    NASA Astrophysics Data System (ADS)

    Daimaruya, M.; Fujiki, H.; Ambarita, H.; Kobayashi, H.; Shin, H.-S.

    2013-07-01

    The present study is concerned with the development of a fracture criterion for the impact fracture of jointed steel plates of bolted joints used in a car body, which contributes to crash simulations by CAE. We focus our attention on the shear fracture of the jointed steel plates of lap-bolted joints in the suspension of a car under impact load. Members of lap-bolted joints are modelled as a pair of steel plates connected by a bolt. One of the plates is a specimen subjected to plastic deformation and fracture and the other is a jig subjected to elastic deformation only. Three kinds of steel plate specimens are examined, i.e., a common steel plate with a tensile strength of 270 MPa and high tensile strength steel plates of 440 and 590 MPa used for cars. The impact shear test was performed using the split Hopkinson bar technique for tension impact, together with the static test using a universal testing machine INSTRON 5586. The behaviour of the shear stress and deformation up to rupture taking place in the joint was discussed. The obtained results suggest that a stress-based fracture criterion may be developed for the impact fracture of jointed steel plates of a lap-bolted joint.

  5. Impact extractive fracture of jointed steel plates of a bolted joint

    NASA Astrophysics Data System (ADS)

    Daimaruya, M.; Fujiki, H.; Ambarita, H.

    2012-08-01

    This study is concerned with the development of a fracture criterion for the impact fracture of jointed steel plates of a bolted joint used in a car body. For the accurate prediction of crash characteristics of car bodies by computer-aided engineering (CAE), it is also necessary to examine the behavior and fracture of jointed steel plates subjected to impact loads. Although the actual impact fracture of jointed steel plates of a bolted joint used in cars is complicated, for simplifying the problem it might be classified into the shear fracture and the extractive fracture of jointed steel plates. Attention is given to the extractive fracture of jointed steel plates in this study. The extractive behavior and fracture of three kinds of steel plates used for cars are examined in experiments and numerical simulations. The impact extraction test of steel plates jointed by a bolt is performed using the one-bar method, together with the static test. In order to understand the mechanism of extractive fracture process of jointed steel plates, numerical simulations by a FEM code LS-DYNA are also carried out. The obtained results suggest that a stress-based fracture criterion may be developed for the impact extractive fracture of jointed steel plates of a bolted joint used in a car body.

  6. Analysis of Yielding Steel Arch Support with Rock Bolts in Mine Roadways Stability Aspect

    NASA Astrophysics Data System (ADS)

    Majcherczyk, Tadeusz; Niedbalski, Zbigniew; Małkowski, Piotr; Bednarek, łukasz

    2014-10-01

    The result of the search for new technological solutions in the field of support for roadways in coal mines has in recent years been the widespread use of steel arch with rockbolt support systems. The efficiency of these systems is affected among other things by the option of installing rock bolts after the actual driving the mine roadway, the increased load capacity that these systems can support, and their resistance to dynamic weight. Large variation in the way that these steel arch support can be connected using different types of rock bolts necessitates mining research revealing the effectiveness of such solutions. Although the steel arch with rockbolt support system is used in the majority of European coal mines, it is still not possible to apply templates of schemes due to the diversity of geological and mining conditions. Therefore, throughout a period of several years, the authors of this article conducted research in situ under conditions of different schemes related to connecting arched support frames with rock bolts, with only selected results being presented in the article. The measurements of convergence, load supported by the system frame, load supported by the rock bolts, and the stratification of roof rocks were analyzed, carried out in two roadways with yielding steel arch support in which strand bolts were applied. The article also proposes the index for working maintenance nuw, used in preliminarily assessing the stability of a given working with a limited number of data concerning geomechanical conditions. Additionally considered are empirical methods used in Poland for designing steel arch with rock bolt support systems. The results of mine research indicate that strengthening yielding steel support with strand bolts through steel beams maintains the stability of a roadway, even when exposed to the exploitation stress. Aside from the impact of exploitation, deformations of the support system are negligible, despite the fact that the tensile

  7. Modified Steels for Cold-Forming U-Bolts Used In Leaf Springs Systems

    NASA Astrophysics Data System (ADS)

    Ventura, J. M.; Castro, D. B. V.; Ruckert, C. O. F. T.; Maluf, O.; Bose Filho, W. W. B.; Spinelli, D.

    2009-10-01

    In this work, a low alloy steel and a fabrication process were developed to produce U-Bolts for commercial vehicles. Thus, initially five types of no-heat treated steel were developed with different additions of chrome, nickel, and silicon to produce strain hardening effect during cold-forming processing of the U-Bolts, assuring the required mechanical properties. The new materials exhibited a fine perlite and ferrite microstructure due to aluminum and vanadium additions, well known as grain size refiners. The mechanical properties were evaluated in a servo-hydraulic test machine system—MTS 810 according to ASTM A370-03; E739 and E08m-00 standards. The microstructure and fractography analyses of the cold-formed steels were performed by using optical and scanning electronic microscope techniques. To evaluate the performance of the steels and the production process, fatigue tests were carried out under load control (tensile-tensile), R = 0.1 and f = 30 Hz. The Weibull statistic methodology was used for the analysis of the fatigue results. At the end of this work the 0.21% chrome content steel, Alloy 2, presented the best fatigue performance.

  8. Behavior of Fiber Glass Bolts, Rock Bolts and Cable Bolts in Shear

    NASA Astrophysics Data System (ADS)

    Li, Xuwei; Aziz, Naj; Mirzaghorbanali, Ali; Nemcik, Jan

    2016-07-01

    This paper experimentally compares the shear behavior of fiber glass (FG) bolt, rock bolt (steel rebar bolt) and cable bolt for the bolt contribution to bolted concrete surface shear strength, and bolt failure mode. Two double shear apparatuses of different size were used for the study. The tensile strength, the shear strength and the deformation modulus of bolt control the shear behavior of a sheared bolted joint. Since the strength and deformation modulus of FG bolt, rock bolt and cable bolt obtained from uniaxial tensile tests are different, their shear behavior in reinforcing joints is accordingly different. Test results showed that the shear stiffness of FG bolted joints decreased gradually from the beginning to end, while the shear stiffness of joints reinforced by rock bolt and cable bolt decreased bi-linearly, which is clearly consistent with their tensile deformation modulus. The bolted joint shear stiffness was highly influenced by bolt pretension in the high stiffness stage for both rock bolt and cable bolt, but not in the low stiffness stage. The rock bolt contribution to joint shear strength standardised by the bolt tensile strength was the largest, followed by cable bolts, then FG bolts. Both the rock bolts and cable bolts tended to fail in tension, while FG bolts in shear due to their low shear strength and constant deformation modulus.

  9. Static and Fatigue Strength Evaluations for Bolted Composite/Steel Joints for Heavy Vehicle Chassis Components

    SciTech Connect

    Sun, Xin; Stephens, Elizabeth V.; Herling, Darrell R.

    2004-09-14

    In May 2003, ORNL and PNNL began collaboration on a four year research effort focused on developing joining techniques to overcome the technical issues associated with joining lightweight materials in heavy vehicles. The initial focus of research is the development and validation of joint designs for a composite structural member attached to a metal member that satisfy the structural requirements both economically and reliably. Huck-bolting is a common joining method currently used in heavy truck chassis structures. The initial round of testing was conducted to establish a performance benchmark by evaluating the static and fatigue behavior of an existing steel/steel chassis joint at the single huck-bolt level. Both tension and shear loading conditions were considered, and the resulting static and fatigue strengths will be used to guide the joint design for a replacement composite/steel joint. A commercially available, pultruded composite material was chosen to study the generic issues related to composite/steel joints. Extren is produced by STRONGWELL, and it is a combination of fiberglass reinforcement and thermosetting polyester or vinyl ester resin systems. Extren sheets of 3.2 mm thick were joined to 1.4 mm SAE1008 steel sheets with a standard grade 5 bolt with 6.35 mm diameter. Both tension and shear loading modes were considered for the single hybrid joint under static and fatigue loading conditions. Since fiberglass reinforced thermoset polymer composites are a non-homogenous material, their strengths and behavior are dependent upon the design of the composite and reinforcement. The Extren sheet stock was cut along the longitudinal direction to achieve maximum net-section strength. The effects of various manufacturing factors and operational conditions on the static and fatigue strength of the hybrid joint were modeled and experimentally verified. It was found that loading mode and washer size have significant influence on the static and fatigue strength of

  10. Behavior of a steel-liner-and-bolts system under very high thermal and mechanical loading: The CONVEX Liner Add-On to DIAMOND FORTUNE

    NASA Astrophysics Data System (ADS)

    Heuze, F. E.; Swift, R. P.; Hill, L. R.; Barrett, W. H.

    1993-01-01

    This work involved the response of a liner-bolt system installed on the wall of the DIAMOND FORTUNE cavity, a 22-m diameter nearly semi-spherical chamber in tuff, at the Nevada Test Site. DIAMOND FORTUNE is a low-yield nuclear test of the Defense Nuclear Agency which was performed in April, 1992. A 1.4-m square, 2.5-cm thick steel plate was anchored by 9-m long bolts: four 2.5-cm diameter bolts at the comers and a 5-cm diameter bolt at the center. The bolt ends daylighted in a tunnel surrounding the cavity, and were tensioned from there. The system was aped with 20 data channels for strain, acceleration, contact pressure, and temperature. We relate the thermal analyses and the 3-dimensional dynamic analyses performed for this project, and we present the test results which indicated the excellent response of this system to the high dynamic loads and temperatures.

  11. Atmospheric corrosion of hot-dip galvanized bolts for fastening weathering steel guiderail

    SciTech Connect

    Townsend, H.E.; Gorman, C.D. ) Fischer, R.J. )

    1999-03-01

    The life of galvanized fastener coatings is only slightly reduced by coupling to weathering steel, provided the initial coating is thick enough to endure an initial period of galvanic attack prior to the development of a protective rust layer on the weathering steel. Typical thicknesses of hot-dip galvanized coatings (3 to 5 mil [76 to 127 [micro]m]) are adequate. Discoloration on the surface of weathering steel exposed to drainage from galvanized fasteners is superficial, and decreases with time of exposure.

  12. Removable Type Expansion Bolt Innovative Design

    NASA Astrophysics Data System (ADS)

    Wang, Feng-Lan; Zhang, Bo; Gao, Bo; Liu, Yan-Xin; Gao, Bo

    2016-05-01

    Expansion bolt is a kind of the most common things in our daily life. Currently, there are many kinds of expansion bolts in the market. However, they have some shortcomings that mainly contain underuse and unremovement but our innovation of design makes up for these shortcomings very well. Principle of working follows this: expansion tube is fixed outside of bolt, steel balls and expansion covers are fixed inside. Meanwhile, the steel balls have 120° with each other. When using it ,expansion cover is moved in the direction of its internal part. So the front part of expansion bolt cover is increasingly becoming big and steel halls is moved outside. Only in this way can it be fixed that steel balls make expansion tube expand. When removing them, expansion bolt is moved outside. So the front part of expansion bolt cover is gradually becoming small and steel balls moves inside, after expansion tube shrinks, we can detach them.

  13. Stress corrosion of low alloy steels used in external bolting on pressurised water reactors

    SciTech Connect

    Skeldon, P.; Hurst, P.; Smart, N.R.

    1992-12-31

    The stress corrosion cracking (SCC) susceptibility of AISI 4140 and AISI 4340 steels has been evaluated in five environments, three simulating a leaking aqueous boric acid environment and two simulating ambient external conditions ie moist air and salt spray. Both steels were found to be highly susceptible to SCC in all environments at hardnesses of 400 VPN and above. The susceptibility was greatly reduced at hardnesses below 330 VPN but in one environment, viz refluxing PWR primary water, SCC was observed at hardnesses as low as 260VPN. Threshold stress intensities for SCC were frequently lower than those in the literature.

  14. Busting bolts

    NASA Astrophysics Data System (ADS)

    Scott, Alan

    2013-05-01

    A simple apparatus is described which serves as a materials testing laboratory. Bolts are placed in it and subjected to tensile and torsional stress while being tightened. The tensile and torsional stress and strain can be measured, which enables the determination of several mechanical properties of the bolt material, including Young’s modulus, yield stress and ultimate stress.

  15. Busting Bolts

    ERIC Educational Resources Information Center

    Scott, Alan

    2013-01-01

    A simple apparatus is described which serves as a materials testing laboratory. Bolts are placed in it and subjected to tensile and torsional stress while being tightened. The tensile and torsional stress and strain can be measured, which enables the determination of several mechanical properties of the bolt material, including Young's…

  16. Bolt-loosening identification of bolt connections by vision image-based technique

    NASA Astrophysics Data System (ADS)

    Nguyen, Tuan-Cuong; Huynh, Thanh-Canh; Ryu, Joo-Young; Park, Jae-Hyung; Kim, Jeong-Tae

    2016-04-01

    In this study, an algorithm using image processing techniques is proposed to identify bolt-loosening in bolted connections of steel structures. Its basic concept is to identify rotation angles of nuts from a pictured image, and is mainly consisted of the following 3 steps: (1) taking a picture for a bolt joint, (2) segmenting the images for each nut by image processing techniques, and (3) identifying rotation angle of each nut and detecting bolt-loosening. By using the concept, an algorithm is designed for continuous monitoring and inspection of the bolt connections. As a key imageprocessing technique, Hough transform is used to identify rotation angles of nuts, and then bolt-loosening is detected by comparing the angles before and after bolt-loosening. Then the applicability of the proposed algorithm is evaluated by experimental tests for two lab-scaled models. A bolted joint model which consists of a splice plate and 8 sets of bolts and nuts with 2×4 array is used to simulate inspection of bridge connections, and a model which is consisted of a ring flange and 32 sets of bolt and nut is used to simulate continuous monitoring of bolted connections in wind turbine towers.

  17. Bolt failure detection

    DOEpatents

    Sutton, Jr., Harry G.

    1984-01-01

    Bolts of a liquid metal fast breeder reactor, each bolt provided with an internal chamber filled with a specific, unique radioactive tag gas. Detection of the tag gas is indicative of a crack in an identifiable bolt.

  18. Performance of D-bolts Under Static Loading

    NASA Astrophysics Data System (ADS)

    Li, Charlie C.

    2012-03-01

    D-bolt is a type of energy-absorbing rock bolt. It is made of a smooth steel bar with anchors spaced along the bolt length. A typical section between adjacent anchors is approximately 1-m long, but it can be adjusted to adapt to the rock conditions. The bolt is fully encapsulated with either cement or resin grout in a borehole. The anchors are firmly fixed into the grout, while the smooth bolt sections can freely deform to absorb deformation energy. Full-scale static pull tests were carried out at different testing facilities in two laboratories. The tests show that a smooth bolt section between anchors may elongate by 110-167 mm depending on the section length. Field trials of the D-bolt were conducted in deep metal mines. The measurements showed that the D-bolts were equally loaded within every anchor-between section, avoiding load peaks and premature bolt failure due to stress concentrations caused by fracture/joint opening. The field trials of rebar and D-bolts in a largely deformed mine tunnel showed that the D-bolts behaved satisfactorily, with only a few failed bolts, while a number of the rebar bolts failed at the thread.

  19. Thrust bolting: roof bolt support apparatus

    DOEpatents

    Tadolini, Stephen C.; Dolinar, Dennis R.

    1992-01-01

    A method of installing a tensioned roof bolt in a borehole of a rock formation without the aid of a mechanical anchoring device or threaded tensioning threads by applying thrust to the bolt (19) as the bonding material (7') is curing to compress the strata (3) surrounding the borehole (1), and then relieving the thrust when the bonding material (7') has cured.

  20. Piezoelectric Bolt Breakers and Bolt Fatigue Testers

    NASA Technical Reports Server (NTRS)

    Sherrit, Stewart; Badescu, Mircea; Bar-Cohen, Yoseph; Barengoltz, Jack; Heckman, Vanessa

    2008-01-01

    A proposed family of devices for inducing fatigue in bolts in order to break the bolts would incorporate piezoelectric actuators into resonant fixtures as in ultrasonic/ sonic drills/corers and similar devices described in numerous prior NASA Tech Briefs articles. These devices were originally intended primarily for use as safer, more-reliable, more-versatile alternatives to explosive bolts heretofore used to fasten spacecraft structures that must subsequently be separated from each other quickly on command during flight. On Earth, these devices could be used for accelerated fatigue testing of bolts. Fatigue theory suggests that a bolt subjected to both a constant-amplitude dynamic (that is, oscillatory) stress and a static tensile stress below the ultimate strength of the bolt material will fail faster than will a bolt subjected to only the dynamic stress. This suggestion would be applied in a device of the proposed type. The device would be designed so that the device and the bolt to be fatigue-tested or broken would be integral parts of an assembly (see figure). The static tension in the tightened bolt would apply not only the clamping force to hold the joined structures (if any) together but also the compression necessary for proper operation of the piezoelectric actuators as parts of a resonant structural assembly. The constant-amplitude dynamic stress would be applied to the bolt by driving the piezoelectric actuators with a sinusoidal voltage at the resonance frequency of longitudinal vibration of the assembly. The amplitude of the excitation would be made large enough so that the vibration would induce fatigue in the bolt within an acceptably short time. In the spacecraft applications or in similar terrestrial structural-separation applications, devices of the proposed type would offer several advantages over explosive bolts: Unlike explosive bolts, the proposed devices would be reusable, could be tested before final use, and would not be subject to

  1. 46 CFR 56.90-5 - Bolting procedure.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... contact faces bear uniformly on the gasket and then shall be made up with relatively uniform bolt stress... principles applicable to the type of gasket used. (c) Steel to cast iron flanged joints shall be...

  2. 46 CFR 56.90-5 - Bolting procedure.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... contact faces bear uniformly on the gasket and then shall be made up with relatively uniform bolt stress... principles applicable to the type of gasket used. (c) Steel to cast iron flanged joints shall be...

  3. Bolt cutter functional evaluation

    NASA Technical Reports Server (NTRS)

    Goldstein, S.; Wong, T. E.; Frost, S. W.; Gageby, J. V.; Pan, R. B.

    1994-01-01

    The Aerospace Corporation has been implementing finite difference and finite element codes for the analysis of a variety of explosive ordnance devices. Both MESA-2D and DYNA3D have been used to evaluate the role of several design parameters on the performance of a satellite separation system bolt cutter. Due to a lack of high strain rate response data for the materials involved, the properties for the bolt cutter and the bolt were selected to achieve agreement between computer simulation and observed characteristics of the recovered test hardware. The calculations provided insight into design parameters such as the cutter blade kinetic energy, the preload on the bolt, the relative position of the anvil, and the anvil shape. Modeling of the cutting process clarifies metallographic observation of both cut and uncut bolts obtained from several tests. Understanding the physical processes involved in bolt cutter operation may suggest certain design modifications that could improve performance margin without increasing environmental shock response levels.

  4. Bolt Stress Monitor

    NASA Technical Reports Server (NTRS)

    1978-01-01

    In photo, an engineer is using a new Ultrasonic Bolt Stress Monitor developed by NASA's Langley Research Center to determine whether a bolt is properly tightened. A highly accurate device, the monitor is an important tool in construction of such structures as pressure vessels, bridges and power plants, wherein precise measurement of the stress on a tightened bolt is critical. Overtightened or undertightened bolts can fail and cause serious industrial accidents or costly equipment break-downs. There are a number of methods for measuring bolt stress. Most widely used and least costly is the torque wrench, which is inherently inaccurate; it does not take into account the friction between nut and bolt, which has an influence on stress. At the other end of the spectrum, there are accurate stress-measuring systems, but they are expensive and not portable. The battery-powered Langley monitor fills a need; it is inexpensive, lightweight, portable and extremely accurate because it is not subject to friction error. Sound waves are transmitted to the bolt and a return signal is received. As the bolt is tightened, it undergoes changes in resonance due to stress, in the manner that a violin string changes tone when it is tightened. The monitor measures the changes in resonance and provides a reading of real stress on the bolt. The device, patented by NASA, has aroused wide interest and a number of firms have applied for licenses to produce it for the commercial market.

  5. Ultrasonic Bolt Gage

    NASA Technical Reports Server (NTRS)

    Gleman, Stuart M. (Inventor); Rowe, Geoffrey K. (Inventor)

    1999-01-01

    An ultrasonic bolt gage is described which uses a crosscorrelation algorithm to determine a tension applied to a fastener, such as a bolt. The cross-correlation analysis is preferably performed using a processor operating on a series of captured ultrasonic echo waveforms. The ultrasonic bolt gage is further described as using the captured ultrasonic echo waveforms to perform additional modes of analysis, such as feature recognition. Multiple tension data outputs, therefore, can be obtained from a single data acquisition for increased measurement reliability. In addition, one embodiment of the gage has been described as multi-channel, having a multiplexer for performing a tension analysis on one of a plurality of bolts.

  6. Small-Bolt Torque-Tension Tester

    NASA Technical Reports Server (NTRS)

    Posey, Alan J.

    2009-01-01

    The device described here measures the torque-tension relationship for fasteners as small as #0. The small-bolt tester consists of a plate of high-strength steel into which three miniature load cells are recessed. The depth of the recess is sized so that the three load cells can be shimmed, the optimum height depending upon the test hardware. The three miniature load cells are arranged in an equilateral triangular configuration with the test bolt aligned with the centroid of the three. This is a kinematic arrangement.

  7. Automatic, computerized testing of bolts

    NASA Technical Reports Server (NTRS)

    Carlucci, J., Jr.; Lobb, V. B.; Stoller, F. W.

    1970-01-01

    System for testing bolts with various platings, lubricants, nuts, and tightening procedures tests 200 fasteners, and processes and summarizes the results, within one month. System measures input torque, nut rotation, bolt clamping force, bolt shank twist, and bolt elongation, data is printed in report form. Test apparatus is described.

  8. Eddy-Current Detection of Weak Bolt Heads

    NASA Technical Reports Server (NTRS)

    Messina, C. P.

    1987-01-01

    Electronic test identifies flawed units passing hardness tests. Eddy-current test detects weakness in head-to-shank junctions of 1/4-28 cup-washer lock bolts. Developed for alloy A286 steel bolts in Space Shuttle main engine fuel turbo-pump. Test examines full volume of head, including head-to-shank transition and nondestructively screens out potentially defective units. Test adapts to any other alloys.

  9. Measuring mine roof bolt strains

    DOEpatents

    Steblay, Bernard J.

    1986-01-01

    A mine roof bolt and a method of measuring the strain in mine roof bolts of this type are disclosed. According to the method, a flat portion on the head of the mine roof bolt is first machined. Next, a hole is drilled radially through the bolt at a predetermined distance from the bolt head. After installation of the mine roof bolt and loading, the strain of the mine roof bolt is measured by generating an ultrasonic pulse at the flat portion. The time of travel of the ultrasonic pulse reflected from the hole is measured. This time of travel is a function of the distance from the flat portion to the hole and increases as the bolt is loaded. Consequently, the time measurement is correlated to the strain in the bolt. Compensation for various factors affecting the travel time are also provided.

  10. A STUDY ON HIGH STRENGTH BOLTED JOINT WITH METAL-SPRAYED CONTACT SURFACES

    NASA Astrophysics Data System (ADS)

    Minami, Kuniaki; Saito, Masamichi; Yokoyama, Hideki; Sugimoto, Ichiro; Nojima, Takao; Masunaga, Toshihiko; Nagasaki, Eiji

    Slip coefficient of high-strength bolt friction joints is well known to depend on the condition of contact surfaces. The coefficient is determined as 0.4 in the Specifications for Highway Bridges and the Design Standards for Railway Structures and Commentary (Steel Structures) in Japan, in the condition of roughened contact surfaces with mill scale removed or painted contact surfaces with inorganic zinc rich paint. However, the slip coefficient with metal-sprayed surfaces is not clear. For the joints with metalsprayed surfaces, hot-dip galvanized bolts are applied and such bolts are tightened by turn-of-nut method. However, it is unclear how much axial force is induced into the bolts in the joints with metal-sprayed surfaces. In order to examine slip coefficient of the bolted joints with metal-sprayed contact surfaces slip tests of high strength bolted joints were carried out. On the basis of above examinations, the slip coefficient with metal-sprayed surfaces is proposed in this paper. To clarify the induced axial force of the bolts, bolt-tightening tests were carried out. Considering bolt diameter, bolt length, induced axial forces and their relaxation, nut rotation angles are proposed in relation to different bolt size.

  11. Bolt and nut evaluator

    NASA Technical Reports Server (NTRS)

    Kerley, James J. (Inventor); Burkhardt, Raymond (Inventor); White, Steven (Inventor)

    1994-01-01

    A device for testing fasteners such as nuts and bolts is described which consists of a fixed base plate having a number of threaded and unthreaded holes of varying size for receiving the fasteners to be tested, a torque marking paper taped on top the fixed base plate for marking torque-angle indicia, a torque wrench for applying torque to the fasteners being tested, and an indicator for showing the torque applied to the fastener. These elements provide a low cost, nondestructive device for verifying the strength of bolts and nuts.

  12. Factors Influencing the Quality of Encapsulation in Rock Bolting

    NASA Astrophysics Data System (ADS)

    Aziz, Naj; Craig, Peter; Mirzaghorbanali, Ali; Nemcik, Jan

    2016-08-01

    Bolt installation quality is influenced by various factors, some are well known and others are less recognised. A programme of field and laboratory studies was undertaken to examine various factors of relevance to the load transfer mechanism between the bolt, resin and rock to ensure test methods truly represent field performance. Short encapsulation tests were undertaken as part of the Australian Coal Association Research Program (ACARP) funded project (C21011) with the ultimate aim of developing standard test methods for assessing bolt encapsulation with chemical resin anchor installations. The field study consisted of a series of Short Encapsulation Pull Tests (SEPT) carried out in three mines with different geological conditions to determine the most representative and practical method of SEPT. Additional field work included installation of bolts into threaded steel tubes for subsequent removal and laboratory evaluation. A series of pull tests was carried out by installing bolts in overhead rig mounted sandstone block, cast in concrete with controlled encapsulation length. Factors of importance considered included; borehole diameter, resin annulus thickness, installation time (including bolt spin to the back and "spin at back"), the effect of gloving and hole over drill. It was found that the borehole diameter had a detrimental effect on the encapsulation bonding strength. Bolt installation time of approximately 10 s constituted an acceptable time for effective bolt installation and within the resin manufacturers recommended time of 14 s. Maintaining constant length of encapsulation was paramount for obtaining consistency and repeatability of the test results. Finally, a numerical simulation study was carried out to assess the capabilities of FLAC 2D software in simulating the pull testing of rock bolts.

  13. Mold bolt and means for achieving close tolerances between bolts and bolt holes

    NASA Technical Reports Server (NTRS)

    Johnston, David L. (Inventor); Bryant, Phillip G. (Inventor)

    1993-01-01

    In the space shuttle, a cargo bay storage rack was required which was to be manufactured from a metal-plastic composite and bolted to a cargo structure. Following completion, utilization of the rack was disallowed due to tolerances, that is, the size differences between the outside bolt diameter and the inside hole diameter. In addition to the space shuttle problem there are other close tolerance requirements for bolts. Such environments often benefit from close tolerance bolting. Frequently such fabrication is not cost effective. Consequently there is a need for means of achieving close tolerances between bolts and bolt holes. Such means are provided. After compressing the elements together a strong rigid plastic, ceramic, or ceramic plastic fluid is forced into a channel extending through the bolt.

  14. Analysis of Inflatable Rock Bolts

    NASA Astrophysics Data System (ADS)

    Li, Charlie C.

    2016-01-01

    An inflatable bolt is integrated in the rock mass through the friction and mechanical interlock at the bolt-rock interface. The pullout resistance of the inflatable bolt is determined by the contact stress at the interface. The contact stress is composed of two parts, termed the primary and secondary contact stresses. The former refers to the stress established during bolt installation and the latter is mobilized when the bolt tends to slip in the borehole owing to the roughness of the borehole surface. The existing analysis of the inflatable rock bolt does not appropriately describe the interaction between the bolt and the rock since the influence of the folded tongue of the bolt on the stiffness of the bolt and the elastic rebound of the bolt tube in the end of bolt installation are ignored. The interaction of the inflatable bolt with the rock is thoroughly analysed by taking into account the elastic displacements of the rock mass and the bolt tube during and after bolt installation in this article. The study aims to reveal the influence of the bolt tongue on the contact stress and the different anchoring mechanisms of the bolt in hard and soft rocks. A new solution to the primary contact stress is derived, which is more realistic than the existing one in describing the interaction between the bolt and the rock. The mechanism of the secondary contact stress is also discussed from the point of view of the mechanical behaviour of the asperities on the borehole surface. The analytical solutions are in agreement with both the laboratory and field pullout test results. The analysis reveals that the primary contact stress decreases with the Young's modulus of the rock mass and increases with the borehole diameter and installation pump pressure. The primary contact stress can be easily established in soft and weak rock but is low or zero in hard and strong rock. In soft and weak rock, the primary contact stress is crucially important for the anchorage of the bolt, while

  15. 30 CFR 75.204 - Roof bolting.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... accessories addressed in ASTM F432-95, “Standard Specification for Roof and Rock Bolts and Accessories,” the.... (4) In each roof bolting cycle, the actual torque or tension of the first tensioned roof bolt... during each roof bolting cycle shall be tested during or immediately after the first row of bolts...

  16. 30 CFR 75.204 - Roof bolting.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... accessories addressed in ASTM F432-95, “Standard Specification for Roof and Rock Bolts and Accessories,” the.... (4) In each roof bolting cycle, the actual torque or tension of the first tensioned roof bolt... during each roof bolting cycle shall be tested during or immediately after the first row of bolts...

  17. 30 CFR 75.204 - Roof bolting.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... accessories addressed in ASTM F432-95, “Standard Specification for Roof and Rock Bolts and Accessories,” the.... (4) In each roof bolting cycle, the actual torque or tension of the first tensioned roof bolt... during each roof bolting cycle shall be tested during or immediately after the first row of bolts...

  18. 30 CFR 75.204 - Roof bolting.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... accessories addressed in ASTM F432-95, “Standard Specification for Roof and Rock Bolts and Accessories,” the.... (4) In each roof bolting cycle, the actual torque or tension of the first tensioned roof bolt... during each roof bolting cycle shall be tested during or immediately after the first row of bolts...

  19. Inexpensive Bolt-Load Gage

    NASA Technical Reports Server (NTRS)

    Long, M. J.

    1983-01-01

    "Built-in" gage determines whether large bolt or stud has been torqued to desired load and provides for continuous inspection to ensure proper load is being maintained. Gage detects longitudinal stress/strain bolt; requires no electronic or sonic test equipment.

  20. Post-Service Examination of PWR Baffle Bolts, Part I. Examination and Test Plan

    SciTech Connect

    Leonard, Keith J.; Sokolov, Mikhail A.; Gussev, Maxim N.

    2015-04-30

    In support of extended service and current operations of the US nuclear reactor plants, the Oak Ridge National Laboratory (ORNL), through the Department of Energy (DOE), Light Water Reactor Sustainability (LWRS) Program, is coordinating with Ginna Nuclear Power Plant, The Westinghouse Electric Company, LLC, and ATI Consulting, the selective procurement of baffle bolts that were withdrawn from service in 2011 and currently stored on site at Ginna. The goal of this program is to perform detailed microstructural and mechanical property characterization of baffle former bolts following in-service exposures. This report outlines the selection criteria of the bolts and the techniques to be used in this study. The bolts available are the original alloy 347 steel fasteners used in holding the baffle plates to the baffle former structures within the lower portion of the pressurized water reactor vessel. Of the eleven possible bolts made available for this work, none were identified to have specific damage. The bolts, however, did show varying levels of breakaway torque required in their removal. The bolts available for this study varied in peak fluence (highest dose within the head of the bolt) between 9.9 and 27.8x1021 n/cm2 (E>1MeV). As no evidence for crack initiation was determined for the available bolts from preliminary visual examination, two bolts with the higher fluence values were selected for further post-irradiation examination. The two bolts showed different breakaway torque levels necessary in their removal. The information from these bolts will be integral to the LWRS program initiatives in evaluating end of life microstructure and properties. Furthermore, valuable data will be obtained that can be incorporated into model predictions of long-term irradiation behavior and compared to results obtained in high flux experimental reactor conditions. The two bolts selected for the ORNL study will be shipped to Westinghouse with bolts of

  1. Space Shuttle orbiter separation bolts

    NASA Technical Reports Server (NTRS)

    Ritchie, R. S.

    1979-01-01

    Evolution of the space shuttle from previous spacecraft systems dictated growth and innovative design of previously standard ordnance devices. Initially, one bolt design was programmed for both 747 and external tank application. However, during development and subsequent analyses, two distinct designs evolved. The unique requirements of both bolts include: high combined loading, redundant initiation, flush separation plane, self-righting and shank attenuation. Of particular interest are the test methods, problem areas, and use of subscale models which demonstrated feasibility at an early phase in the program. The techniques incorporated in the shuttle orbiter bolts are applicable to other mechanisms.

  2. Effects of bolt-hole contact on bearing-bypass damage-onset strength

    NASA Technical Reports Server (NTRS)

    Crews, John H., Jr.; Naik, Rajiv A.

    1991-01-01

    A combined experimental and analytical study was conducted to investigate the effects of bolt-hole contact on the bearing bypass strength of a graphite-epoxy laminate. Tests were conducted on specimens consisting of 16-ply quasi-isotropic T300/5208 laminates with a centrally located hole. Bearing loads were applied through a clearance-fit steel bolt. Damage onset strength and damage mode were determined for each test case. A finite element procedure was used to calculate the bolt-hole stresses and bolt contact for each test case. A finite element procedure was used to calculate the bolt-hole stresses and bolt contact for each measured damage-onset strength. For the tension bearing-bypass cases tested, the bolt contact half-angle was approximately 60 degrees at damage onset. For compression, the contact angle was 20 degrees as the bypass load increased. A corresponding decrease in the bearing damage onset strength was attributed to the decrease in contact angle which made the bearing loads more severe. Hole boundary stresses were also computed by superimposing stresses for separate bearing and bypass loading. Stresses at the specimen net section were accurately approximated by the superposition procedure. However, the peak bearing stresses had large errors because the bolt contact angles were not represented correctly. For compression, peak bearing stress errors of nearly 50 percent were calculated.

  3. Analysis of alternatives for using cable bolts as primary support at two low-seam coal mines

    PubMed Central

    Esterhuizen, Gabriel S.; Tulu, Ihsan B.

    2016-01-01

    Cable bolts are sometimes used in low-seam coal mines to provide support in difficult ground conditions. This paper describes cable bolting solutions at two low-seam coal mines in similar ground conditions. Both mines used support systems incorporating cable bolts as part of the primary support system. Two original cable bolt based support systems as well as two modified systems are evaluated to estimate their ability to prevent large roof falls. One of the support systems incorporated passive cable bolts, while the other used pre-tensioned cable bolts. The results and experience at the mines showed that the modified systems provided improved stability over the original support systems. The presence of the cable bolts is the most important contribution to stability against large roof falls, rather than the details of the support pattern. It was also found that a heavy steel channel can improve the safety of the system because of the ‘sling’ action it provides. Additionally, the analysis showed that fully-grouted rebar bolts load much earlier than the cable bolts, and pre-tensioning of the cable bolts can result in a more uniform distribution of loading in the roof. PMID:27722019

  4. Ultrasonic extensometer measures bolt preload

    NASA Technical Reports Server (NTRS)

    Daniels, C. M., Jr.

    1978-01-01

    Extensometer using ultrasonic pulse reflections to measure elongations in tightened belts and studs is much more accurate than conventional torque wrenches in application of specified preload to bolts and other threaded fasteners.

  5. Real time bolt preload monitoring using piezoceramic transducers and time reversal technique—a numerical study with experimental verification

    NASA Astrophysics Data System (ADS)

    Parvasi, Seyed Mohammad; Ho, Siu Chun Michael; Kong, Qingzhao; Mousavi, Reza; Song, Gangbing

    2016-08-01

    Bolted joints are ubiquitous structural elements, and form critical connections in mechanical and civil structures. As such, loosened bolted joints may lead to catastrophic failures of these structures, thus inspiring a growing interest in monitoring of bolted joints. A novel energy based wave method is proposed in this study to monitor the axial load of bolted joint connections. In this method, the time reversal technique was used to focus the energy of a piezoelectric (PZT)-generated ultrasound wave from one side of the interface to be measured as a signal peak by another PZT transducer on the other side of the interface. A tightness index (TI) was defined and used to correlate the peak amplitude to the bolt axial load. The TI bypasses the need for more complex signal processing required in other energy-based methods. A coupled, electro-mechanical analysis with elasto-plastic finite element method was used to simulate and analyze the PZT based ultrasonic wave propagation through the interface of two steel plates connected by a single nut and bolt connection. Numerical results, backed by experimental results from testing on a bolted connection between two steel plates, revealed that the peak amplitude of the focused signal increases as the bolt preload (torque level) increases due to the enlarging true contact area of the steel plates. The amplitude of the focused peak saturates and the TI reaches unity as the bolt axial load reaches a threshold value. These conditions are associated with the maximum possible true contact area between the surfaces of the bolted connection.

  6. A Component-Based Study of the Effect of Diameter on Bond and Anchorage Characteristics of Blind-Bolted Connections.

    PubMed

    Amin, Muhammad Nasir; Zaheer, Salman; Alazba, Abdulrahman Ali; Saleem, Muhammad Umair; Niazi, Muhammad Umar Khan; Khurram, Nauman; Amin, Muhammad Tahir

    2016-01-01

    Structural hollow sections are gaining worldwide importance due to their structural and architectural advantages over open steel sections. The only obstacle to their use is their connection with other structural members. To overcome the obstacle of tightening the bolt from one side has given birth to the concept of blind bolts. Blind bolts, being the practical solution to the connection hindrance for the use of hollow and concrete filled hollow sections play a vital role. Flowdrill, the Huck High Strength Blind Bolt and the Lindapter Hollobolt are the well-known commercially available blind bolts. Although the development of blind bolts has largely resolved this issue, the use of structural hollow sections remains limited to shear resistance. Therefore, a new modified version of the blind bolt, known as the "Extended Hollo-Bolt" (EHB) due to its enhanced capacity for bonding with concrete, can overcome the issue of low moment resistance capacity associated with blind-bolted connections. The load transfer mechanism of this recently developed blind bolt remains unclear, however. This study uses a parametric approach to characterising the EHB, using diameter as the variable parameter. Stiffness and load-carrying capacity were evaluated at two different bolt sizes. To investigate the load transfer mechanism, a component-based study of the bond and anchorage characteristics was performed by breaking down the EHB into its components. The results of the study provide insight into the load transfer mechanism of the blind bolt in question. The proposed component-based model was validated by a spring model, through which the stiffness of the EHB was compared to that of its components combined. The combined stiffness of the components was found to be roughly equivalent to that of the EHB as a whole, validating the use of this component-based approach.

  7. A Component-Based Study of the Effect of Diameter on Bond and Anchorage Characteristics of Blind-Bolted Connections

    PubMed Central

    Amin, Muhammad Nasir; Zaheer, Salman; Alazba, Abdulrahman Ali; Saleem, Muhammad Umair; Niazi, Muhammad Umar Khan; Khurram, Nauman; Amin, Muhammad Tahir

    2016-01-01

    Structural hollow sections are gaining worldwide importance due to their structural and architectural advantages over open steel sections. The only obstacle to their use is their connection with other structural members. To overcome the obstacle of tightening the bolt from one side has given birth to the concept of blind bolts. Blind bolts, being the practical solution to the connection hindrance for the use of hollow and concrete filled hollow sections play a vital role. Flowdrill, the Huck High Strength Blind Bolt and the Lindapter Hollobolt are the well-known commercially available blind bolts. Although the development of blind bolts has largely resolved this issue, the use of structural hollow sections remains limited to shear resistance. Therefore, a new modified version of the blind bolt, known as the “Extended Hollo-Bolt” (EHB) due to its enhanced capacity for bonding with concrete, can overcome the issue of low moment resistance capacity associated with blind-bolted connections. The load transfer mechanism of this recently developed blind bolt remains unclear, however. This study uses a parametric approach to characterising the EHB, using diameter as the variable parameter. Stiffness and load-carrying capacity were evaluated at two different bolt sizes. To investigate the load transfer mechanism, a component-based study of the bond and anchorage characteristics was performed by breaking down the EHB into its components. The results of the study provide insight into the load transfer mechanism of the blind bolt in question. The proposed component-based model was validated by a spring model, through which the stiffness of the EHB was compared to that of its components combined. The combined stiffness of the components was found to be roughly equivalent to that of the EHB as a whole, validating the use of this component-based approach. PMID:26901866

  8. Common Bolted Joint Analysis Tool

    NASA Technical Reports Server (NTRS)

    Imtiaz, Kauser

    2011-01-01

    Common Bolted Joint Analysis Tool (comBAT) is an Excel/VB-based bolted joint analysis/optimization program that lays out a systematic foundation for an inexperienced or seasoned analyst to determine fastener size, material, and assembly torque for a given design. Analysts are able to perform numerous what-if scenarios within minutes to arrive at an optimal solution. The program evaluates input design parameters, performs joint assembly checks, and steps through numerous calculations to arrive at several key margins of safety for each member in a joint. It also checks for joint gapping, provides fatigue calculations, and generates joint diagrams for a visual reference. Optimum fastener size and material, as well as correct torque, can then be provided. Analysis methodology, equations, and guidelines are provided throughout the solution sequence so that this program does not become a "black box:" for the analyst. There are built-in databases that reduce the legwork required by the analyst. Each step is clearly identified and results are provided in number format, as well as color-coded spelled-out words to draw user attention. The three key features of the software are robust technical content, innovative and user friendly I/O, and a large database. The program addresses every aspect of bolted joint analysis and proves to be an instructional tool at the same time. It saves analysis time, has intelligent messaging features, and catches operator errors in real time.

  9. A microprocessor based portable bolt tension monitor

    NASA Astrophysics Data System (ADS)

    Perey, D. F.

    1991-05-01

    A bolt tension monitor (BTM) which uses ultrasonics and a pulsed phase locked loop circuit to measure load-induced acoustic phase shifts which are independent of friction is described. The BTM makes it possible to measure the load in a bolt that was tightened at some time in the past. This capability to recertify a load after-the-fact will help to insure the integrity of a bolted joint.

  10. A microprocessor based portable bolt tension monitor

    NASA Technical Reports Server (NTRS)

    Perey, D. F.

    1991-01-01

    A bolt tension monitor (BTM) which uses ultrasonics and a pulsed phase locked loop circuit to measure load-induced acoustic phase shifts which are independent of friction is described. The BTM makes it possible to measure the load in a bolt that was tightened at some time in the past. This capability to recertify a load after-the-fact will help to insure the integrity of a bolted joint.

  11. Acousto-optic Extensometer for Bolts

    NASA Technical Reports Server (NTRS)

    Maram, J.; Kuhr, G.

    1985-01-01

    Bolt torque or tension deduced from non contacting measurements. Pulsed Laser induces shockwave in bolthead while continuous-wave acousto-optic detector monitors distortion produced by shock. Shock travel time measured to determine bolt length. Solid-state position detector relatively inexpensive and keeps down cost of extensometer.

  12. 30 CFR 75.204 - Roof bolting.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Roof Support § 75.204 Roof bolting. (a) For roof bolts and... successfully supported the roof in an area of a coal mine with similar strata, opening dimensions and...

  13. 46 CFR 56.25-20 - Bolting.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... reference, see 46 CFR 56.01-2), unless the bolts are tightly fitted to the holes and flange stress... washers must comply with applicable standards and specifications listed in 46 CFR 56.60-1. Unless otherwise specified, bolting must be in accordance with ASME B16.5 (incorporated by reference; see 46 CFR...

  14. Integrity of Bolted Angle Connections Subjected to Simulated Column Removal

    PubMed Central

    Weigand, Jonathan M.; Berman, Jeffrey W.

    2016-01-01

    Large-scale tests of steel gravity framing systems (SGFSs) have shown that the connections are critical to the system integrity, when a column suffers damage that compromises its ability to carry gravity loads. When supporting columns were removed, the SGFSs redistributed gravity loads through the development of an alternate load path in a sustained tensile configuration resulting from large vertical deflections. The ability of the system to sustain such an alternate load path depends on the capacity of the gravity connections to remain intact after undergoing large rotation and axial extension demands, for which they were not designed. This study experimentally evaluates the performance of steel bolted angle connections subjected to loading consistent with an interior column removal. The characteristic connection behaviors are described and the performance of multiple connection configurations are compared in terms of their peak resistances and deformation capacities. PMID:27110059

  15. Non-Destructive Evaluation of Rock Bolts Associated With Optical Strain Sensors at the Homestake Gold Mine

    NASA Astrophysics Data System (ADS)

    Kogle, M. M.; Fratta, D.; Wang, H. F.; Geox^Tm

    2010-12-01

    Fiber-Bragg Grating (FBG) optical strain sensors have been installed in the former Homestake Gold Mine (Lead, SD) as part of an early science project at the Deep Underground Science and Engineering Laboratory (DUSEL). FBG sensors are anchored within an alcove at the 4100’ level of the mine using rock bolts and coupled to the rock mass with resin epoxy and cement grout. The quality of the coupling between the rock bolt and the rock mass is essential to assure that true rock mass strains are being recorded. To evaluate the integrity of the installed rock bolt system, guided ultrasonic waves can be used as a non-destructive monitoring system. The propagation of reflected ultrasonic waves capture information about the degree of coupling between the steel rock bolt and resin epoxy/cement grout and between the resin epoxy/cement grout and the surrounding rock mass, and hence the integrity of the installed rock bolt system. In this study, we use the phase velocity obtained from ultrasonic wave propagation to estimate the rock modulus. In our initial testing we generated a broadband elastic wave along the length of a rock bolt anchored in a concrete cylinder while monitoring multiple reflections with a single accelerometer affixed at the exposed end of the rock bolt. The captured waveforms include several reflections that were then analyzed to obtain frequency response, coherence, phase velocity, and damping between multiple reflections. As the wavelength increases, the response captures first elastic properties of the steel and then the combined elastic properties of the rock bolt/rock mass system. Challenges associated with implementing this non-destructive testing technique in rock masses include the generation of wide bandwidth signals having enough strength to produce multiple reflections with high enough signal-to-noise ratios to capture properties of multi-scale systems.

  16. Corrosion monitoring of rock bolt by using a low coherent fiber-optic interferometry

    NASA Astrophysics Data System (ADS)

    Wei, Heming; Zhao, Xuefeng; Li, Dongsheng; Zhang, Pinglei; Sun, Changsen

    2015-04-01

    Corrosion of rock bolts is a major cause for deterioration of the anchor-reinforced concrete slopes structures. In order to evaluate this corrosion-based deterioration in an early stage, a nondestructive technique was required. However, until now, there are no commercialized solutions that are straightforwardly available. Here, a low-coherent fiber-optic sensing technique was developed. This method can carry out the monitoring of the corrosion-caused expansion at the accuracy of sub-microstrains by circled the sensing optical fiber in two ways. One was wound the fiber on the surface of steel rock bolt directly, and thereby generated a nonuniformity in the interface of cement with rock bolt. The other was circled the fiber on a cement mortar cushion without destroying the interface any way. The sensing fiber was configured as one arm of the fiber-optic Michelson interferometer. The acceleration corrosion experiments demonstrated that a uniform interface between cement and rock bolt determined the progress of corrosion development. An early stage evaluation of the corrosion development in rock bolts was monitored.

  17. 21 CFR 137.280 - Bolted yellow corn meal.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 2 2011-04-01 2011-04-01 false Bolted yellow corn meal. 137.280 Section 137.280... Flours and Related Products § 137.280 Bolted yellow corn meal. Bolted yellow corn meal conforms to the definition and standard of identity prescribed by § 137.255 for bolted white corn meal except that...

  18. 21 CFR 137.280 - Bolted yellow corn meal.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 2 2012-04-01 2012-04-01 false Bolted yellow corn meal. 137.280 Section 137.280... Flours and Related Products § 137.280 Bolted yellow corn meal. Bolted yellow corn meal conforms to the definition and standard of identity prescribed by § 137.255 for bolted white corn meal except that...

  19. 21 CFR 137.280 - Bolted yellow corn meal.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 2 2014-04-01 2014-04-01 false Bolted yellow corn meal. 137.280 Section 137.280... Flours and Related Products § 137.280 Bolted yellow corn meal. Bolted yellow corn meal conforms to the definition and standard of identity prescribed by § 137.255 for bolted white corn meal except that...

  20. 21 CFR 137.280 - Bolted yellow corn meal.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 2 2010-04-01 2010-04-01 false Bolted yellow corn meal. 137.280 Section 137.280... Flours and Related Products § 137.280 Bolted yellow corn meal. Bolted yellow corn meal conforms to the definition and standard of identity prescribed by § 137.255 for bolted white corn meal except that...

  1. 21 CFR 137.280 - Bolted yellow corn meal.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 2 2013-04-01 2013-04-01 false Bolted yellow corn meal. 137.280 Section 137.280... Flours and Related Products § 137.280 Bolted yellow corn meal. Bolted yellow corn meal conforms to the definition and standard of identity prescribed by § 137.255 for bolted white corn meal except that...

  2. The Nuts and Bolts of Chemistry.

    ERIC Educational Resources Information Center

    Volkmann, Mark J.

    1996-01-01

    Presents a teaching strategy to successfully teach the periodic table using nuts and bolts as elemental analogs. Describes activities that enable the student to develop a deeper understanding of the periodic table and how it is organized. (JRH)

  3. Bolt Cutter Blade's Imprint in Toolmarks Examination.

    PubMed

    Volkov, Nikolai; Finkelstein, Nir; Novoselsky, Yehuda; Tsach, Tsadok

    2015-11-01

    Bolt cutters are known as cutting tools which are used for cutting hard objects and materials, such as padlocks and bars. Bolt cutter blades leave their imprint on the cut objects. When receiving a cut object from a crime scene, forensic toolmarks examiners can determine whether the suspected cutting tool was used in a specific crime or not based on class characteristic marks and individual marks that the bolt cutter blades leave on the cut object. The paper presents preliminary results of a study on ten bolt cutters and suggests a quick preliminary examination-the comparison between the blade thickness and the width of the imprint left by the tool on the cut object. Based on the comparison result, if there is not a match, the examiner can eliminate the feasibility of the use of the suspected cutting tool in a specific crime. This examination simplifies and accelerates the comparison procedure. PMID:26257324

  4. Richard H. Bolt: Scientist, educator and friend

    NASA Astrophysics Data System (ADS)

    Beranek, Leo L.

    2003-04-01

    The author will discuss his close relation to Dick Bolt, starting with their first meeting in 1938. This will include Bolt's doctoral years at the University of California, his National Research Fellowship in Physics at MIT, his contributions to the World War II effort, his tenured appointment, guidance of students and formation of the Acoustical Laboratory at MIT, and his co-founding of and subsequent participation in Bolt Beranek and Newman. Dick's principal contributions to the field of acoustics, to education and to the Acoustical Society of America will be presented up until 1957, after which his talents were largely taken over by national missions, which are mentioned. Richard H. Bolt was an inspiring educator, researcher and organizer. He truly was a national treasure.

  5. Stress analysis of closure bolts for shipping casks

    SciTech Connect

    Mok, G.C.; Fischer, L.E. ); Hsu, S.T. )

    1993-01-01

    This report specifies the requirements and criteria for stress analysis of closure bolts for shipping casks containing nuclear spent fuels or high level radioactive materials. The specification is based on existing information conceming the structural behavior, analysis, and design of bolted joints. The approach taken was to extend the ASME Boiler and Pressure Vessel Code requirements and criteria for bolting analysis of nuclear piping and pressure vessels to include the appropriate design and load characteristics of the shipping cask. The characteristics considered are large, flat, closure lids with metal-to-metal contact within the bolted joint; significant temperature and impact loads; and possible prying and bending effects. Specific formulas and procedures developed apply to the bolt stress analysis of a circular, flat, bolted closure. The report also includes critical load cases and desirable design practices for the bolted closure, an in-depth review of the structural behavior of bolted joints, and a comprehensive bibliography of current information on bolted joints.

  6. Development of elastomeric isolators to reduce roof bolting machine drilling noise

    PubMed Central

    Michael, Robert; Yantek, David; Johnson, David; Ferro, Ernie; Swope, Chad

    2015-01-01

    Among underground coal miners, hearing loss remains one of the most common occupational illnesses. In response to this problem, the National Institute for Occupational Safety and Health (NIOSH) Office of Mine Safety and Health Research (OMSHR) conducts research to reduce the noise emission of underground coal-mining equipment, an example of which is a roof bolting machine. Field studies show that, on average, drilling noise is the most significant contributor to a roof bolting machine operator’s noise exposure. NIOSH OMSHR has determined that the drill steel and chuck are the dominant sources of drilling noise. NIOSH OMSHR, Corry Rubber Corporation, and Kennametal, Inc. have developed a bit isolator that breaks the steel-to-steel link between the drill bit and drill steel and a chuck isolator that breaks the mechanical connection between the drill steel and the chuck, thus reducing the noise radiated by the drill steel and chuck, and the noise exposure of the roof bolter operator. This paper documents the evolution of the bit isolator and chuck isolator including various alternative designs which may enhance performance. Laboratory testing confirms that production bit and chuck isolators reduce the A-weighted sound level generated during drilling by 3.7 to 6.6 dB. Finally, this paper summarizes results of a finite element analysis used to explore the key parameters of the drill bit isolator and chuck isolator to understand the impact these parameters have on noise. PMID:26568650

  7. Bolt preload selection for pulsed-loaded vessel closures

    SciTech Connect

    Duffey, T.A.; Lewis, B.B.; Bowers, S.M.

    1995-02-01

    Bounding, closed-form solutions are developed for selecting the bolt preload for a square, flat plate closure subjected to a pressure pulse load. The solutions consider the limiting case in which preload is primarily dependent on closure bending response as well as the limiting case in which preload depends on elastic bolt response. The selection of bolt preload is illustrated. Also presented in the paper is a detailed finite element analysis of dynamically loaded, bolted circular closure. The responses of the structure, closure, and bolts are included, and results are obtained for various preloads. The analysis illustrates a method of bolt preload modeling for use in general finite element computer programs.

  8. 8. GENERAL VIEW OF SHINGLE CUTTING SAWS THAT HANDLE BOLTS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    8. GENERAL VIEW OF SHINGLE CUTTING SAWS THAT HANDLE BOLTS AFTER DEBARKING; AFTER DEBARKING THE BOLTS ARE SENT TO THE SHINGLE WEAVER FOR SAWING - Lester Shingle Mill, 1602 North Eighteenth Street, Sweet Home, Linn County, OR

  9. More Nuts and Bolts of Michaelis-Menten Enzyme Kinetics

    ERIC Educational Resources Information Center

    Lechner, Joseph H.

    2011-01-01

    Several additions to a classroom activity are proposed in which an "enzyme" (the student) converts "substrates" (nut-bolt assemblies) into "products" (separated nuts and bolts) by unscrewing them. (Contains 1 table.)

  10. High-Strength Bolt Corrosion Fatigue Life Model and Application

    PubMed Central

    Hui-li, Wang; Si-feng, Qin

    2014-01-01

    The corrosion fatigue performance of high-strength bolt was studied. Based on the fracture mechanics theory and the Gerberich-Chen formula, the high-strength bolt corrosion fracture crack model and the fatigue life model were established. The high-strength bolt crack depth and the fatigue life under corrosion environment were quantitatively analyzed. The factors affecting high-strength bolt corrosion fatigue life were discussed. The result showed that the high-strength bolt corrosion fracture biggest crack depth reduces along with the material yield strength and the applied stress increases. The material yield strength was the major factor. And the high-strength bolt corrosion fatigue life reduced along with the increase of material strength, the applied stress or stress amplitude. The stress amplitude influenced the most, and the material yield strength influenced the least. Low bolt strength and a low stress amplitude level could extend high-strength bolt corrosion fatigue life. PMID:25152916

  11. High-strength bolt corrosion fatigue life model and application.

    PubMed

    Hui-li, Wang; Si-feng, Qin

    2014-01-01

    The corrosion fatigue performance of high-strength bolt was studied. Based on the fracture mechanics theory and the Gerberich-Chen formula, the high-strength bolt corrosion fracture crack model and the fatigue life model were established. The high-strength bolt crack depth and the fatigue life under corrosion environment were quantitatively analyzed. The factors affecting high-strength bolt corrosion fatigue life were discussed. The result showed that the high-strength bolt corrosion fracture biggest crack depth reduces along with the material yield strength and the applied stress increases. The material yield strength was the major factor. And the high-strength bolt corrosion fatigue life reduced along with the increase of material strength, the applied stress or stress amplitude. The stress amplitude influenced the most, and the material yield strength influenced the least. Low bolt strength and a low stress amplitude level could extend high-strength bolt corrosion fatigue life.

  12. Professional users handbook for rock bolting

    SciTech Connect

    Stillborg, E.B.

    1986-01-01

    All the common rockbolts in current use are considered. The characteristics of these bolts and the installation procedures are discussed. Testing methods for the installed rockbolts are presented, together with the results of the load bearing capacity of different bolts. Design considerations are dealt with, including a discussion of rock mass conditions and rock classification systems. The rock conditions in which a particular type of rockbolt should not be used are reviewed. Design principles for rockbolts in different mass conditions are treated, as well as monitoring and cost of rockbolt systems.

  13. X-38 Bolt Retractor Subsystem Separation Demonstration

    NASA Technical Reports Server (NTRS)

    Rugless, Fedoria (Editor); Johnston, A. S.; Ahmed, R.; Garrison, J. C.; Gaines, J. L.; Waggoner, J. D.

    2002-01-01

    The Flight Robotics Laboratory FRL successfully demonstrated the X-38 bolt retractor subsystem (BRS). The BRS design was proven safe by testing in the Pyrotechnic Shock Facility (PSI) before being demonstrated in the FRL. This Technical Memorandum describes the BRS, FRL, PSF, and interface hardware. Bolt retraction time, spacecraft simulator acceleration, and a force analysis are also presented. The purpose of the demonstration was to show the FRL capability for spacecraft separation testing using pyrotechnics. Although a formal test was not performed due to schedule and budget constraints, the data will show that the BRS is a successful design concept and the FRL is suitable for future separation tests.

  14. 21 CFR 137.255 - Bolted white corn meal.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 2 2013-04-01 2013-04-01 false Bolted white corn meal. 137.255 Section 137.255... Flours and Related Products § 137.255 Bolted white corn meal. (a) Bolted white corn meal is the food prepared by so grinding and sifting cleaned white corn that: (1) Its crude fiber content is less than...

  15. 21 CFR 137.255 - Bolted white corn meal.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 2 2011-04-01 2011-04-01 false Bolted white corn meal. 137.255 Section 137.255... Flours and Related Products § 137.255 Bolted white corn meal. (a) Bolted white corn meal is the food prepared by so grinding and sifting cleaned white corn that: (1) Its crude fiber content is less than...

  16. 21 CFR 137.255 - Bolted white corn meal.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 2 2010-04-01 2010-04-01 false Bolted white corn meal. 137.255 Section 137.255... Flours and Related Products § 137.255 Bolted white corn meal. (a) Bolted white corn meal is the food prepared by so grinding and sifting cleaned white corn that: (1) Its crude fiber content is less than...

  17. 21 CFR 137.255 - Bolted white corn meal.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 2 2014-04-01 2014-04-01 false Bolted white corn meal. 137.255 Section 137.255... Flours and Related Products § 137.255 Bolted white corn meal. (a) Bolted white corn meal is the food prepared by so grinding and sifting cleaned white corn that: (1) Its crude fiber content is less than...

  18. 21 CFR 137.255 - Bolted white corn meal.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 2 2012-04-01 2012-04-01 false Bolted white corn meal. 137.255 Section 137.255... Flours and Related Products § 137.255 Bolted white corn meal. (a) Bolted white corn meal is the food prepared by so grinding and sifting cleaned white corn that: (1) Its crude fiber content is less than...

  19. 46 CFR 56.90-5 - Bolting procedure.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... APPURTENANCES Assembly § 56.90-5 Bolting procedure. (a) All flanged joints shall be fitted up so that the gasket contact faces bear uniformly on the gasket and then shall be made up with relatively uniform bolt stress. Bolt loading and gasket compression need only be verified by touch and visual observation. (b)...

  20. Testing of nuclear grade lubricants and their effects on A540 B24 and A193 B7 bolting materials

    SciTech Connect

    Czajkowski, C.J.

    1985-01-01

    An investigation was performed on eleven commonly used lubricants by the nuclear power industry. The investigation included EDS analysis of the lubricants, notched-tensile constant extension rate testing of bolting materials with the lubricants, frictional testing of the lubricants and weight loss testing of a bonded solid film lubricant. The report generally concludes that there is a significant amount of variance in the mechanical properties of common bolting materials; that MoS/sub 2/ can hydrolyze to form H/sub 2/S at 100/sup 0/C and cause stress corrosion cracking (SCC) of bolting materials, and that the use of copper-containing lubricants can be potentially detrimental to high strength steels in an aqueous environment. Additionally, the testing of various lubricants disclosed that some lubricants contain potentially detrimental elements (e.g. S, Sb) which can promote SCC of the common bolting materials. One of the most significant findings of this report is the observation that both A193 B7 and A540 B24 bolting materials are susceptible to transgranular stress corrosion cracking in demineralized H/sub 2/O at 280/sup 0/C in notched tensile tests.

  1. Ultrasonic pulsed phase locked loop interferometer for bolt load measurements

    NASA Astrophysics Data System (ADS)

    Allison, S. G.; Clendenin, C. G.

    The pulsed phase-locked-loop bolt monitor (P2L2) that uses ultrasonic waves to measure bolt preload with accuracies ranging from 1 to 3 percent (depending on the specific bolt) is described. To remeasure bolt load after installation, a thermal calibration factor compensates for bolt temperature changes, and a standard reference block allows correction for acoustic phase errors due to measurement equipment configuration such as utilization of a different transducer, couplant, or cable. Some examples of critical applications including Space Shuttle landing-gear wheels and NASA wind-tunnel fan blades are discussed.

  2. 46 CFR 56.25-20 - Bolting.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... washers must comply with applicable standards and specifications listed in 46 CFR 56.60-1. Unless otherwise specified, bolting must be in accordance with ASME B16.5 (incorporated by reference; see 46 CFR 56... heavy hexagon heads in accordance with ASME B18.2.1 (incorporated by reference, see 46 CFR 56.01-2)...

  3. 46 CFR 56.25-20 - Bolting.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... washers must comply with applicable standards and specifications listed in 46 CFR 56.60-1. Unless otherwise specified, bolting must be in accordance with ASME B16.5 (incorporated by reference; see 46 CFR 56... heavy hexagon heads in accordance with ASME B18.2.1 (incorporated by reference, see 46 CFR 56.01-2)...

  4. 46 CFR 56.25-20 - Bolting.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... washers must comply with applicable standards and specifications listed in 46 CFR 56.60-1. Unless otherwise specified, bolting must be in accordance with ASME B16.5 (incorporated by reference; see 46 CFR 56... heavy hexagon heads in accordance with ASME B18.2.1 (incorporated by reference, see 46 CFR 56.01-2)...

  5. Inedible Nuts and Non-Lightning Bolts

    ERIC Educational Resources Information Center

    Rynone, William

    2010-01-01

    In this article, the author provides detailed information on a wide variety of commonly used screws, bolts, and other fasteners. The information has been gathered in his engineering career and outside interests (maintenance on his car and airplane, and woodworking). The topic should be of interest to students and educators in many technical…

  6. Factors affecting penetrating captive bolt gun performance.

    PubMed

    Gibson, Troy J; Mason, Charles W; Spence, Jade Y; Barker, Heather; Gregory, Neville G

    2015-01-01

    Captive bolt stunning is used for rendering livestock insensible at slaughter. The mechanical factors relating to performance of 6 penetrating captive bolt gun (CBG) models were examined. The Matador Super Sécurit 3000 and the .25 Cash Euro Stunner had the highest kinetic energy values (443 J and 412 J, respectively) of the CBGs tested. Ninety percent (27/30) of CBGs held at a government gun repository (United Kingdom) were found to have performed at a normal standard for the model, while 53% (10/19) of commercial contractor CBGs tested were found to underperform for the gun model. When the .22 Cash Special was fired 500 times at 4 shots per min, the gun reached a peak temperature of 88.8°C after 2.05 hr. Repeat firing during extended periods significantly reduced the performance of the CBG. When deciding on the appropriate CBG/cartridge combination, the kinetic energy delivered to the head of the nonhuman animal, bolt penetration depth, and species/animal type must be considered. It is recommended that CBGs are routinely checked for wear to the bolt and barrel if they are repeatedly fired in a session.

  7. 46 CFR 56.25-20 - Bolting.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... washers must comply with applicable standards and specifications listed in 46 CFR 56.60-1. Unless otherwise specified, bolting must be in accordance with ASME B16.5 (incorporated by reference; see 46 CFR 56... heavy hexagon heads in accordance with ASME B18.2.1 (incorporated by reference, see 46 CFR 56.01-2)...

  8. Roof bolt apparatus with expansion shell and coupling

    SciTech Connect

    Yacisin, P.A.

    1987-07-14

    An apparatus is described for supporting a rock formation comprising: an elongated rod positioned in a bore hole of a rock formation; the rod having a first threaded end portion and a second threaded end portion positioned adjacent the end of the bore hole; an expansion shell assembly engaged to the rod first threaded end portion, an elongated bolt positioned in the bore hole below the rod second threaded end portion, the bolt having a first threaded end portion and a second end portion; the bolt first threaded end portion positioned oppositely of the rod second threaded end portion; a bearing plate positioned on the bolt second end portion; means for threadedly connecting the bolt to the rod, stop means associated with the means for threadingly connecting the bolt to the rod for limiting axial movement of the bolt relative to the rod to permit unitary rotation of both the bolt and the rod in a preselected direction; the expansion shell assembly operable upon rotation of the rod to anchor the rod in the bore hole; and the bolt being operable to rotate in the preselected direction relative to the rod anchored in the bore hole to disengage the stop means to axially advance the bolt relative to the rod and tension bolt.

  9. Experimental study on tunnel lining joints temporarily strengthened by SMA bolts

    NASA Astrophysics Data System (ADS)

    Wu, Bo; Ou, Yunlong

    2014-12-01

    Shield tunnels have been widely used in city metros all over the world. During the long-term period of the metro operation, the joints of shield tunnel’s neighboring segments may degrade due to some environmental factors, leading to the increasing of the joint opening and some resulting adverse consequences. In this paper, a temporary strengthening method by using shape memory alloy (SMA) bolts is proposed and experimentally studied for the joints of neighboring segments, and a revised electric heating method which suits with the strengthening method is presented and experimentally validated for the SMA bolts. The purpose of the proposed temporary strengthening method is to create favorable conditions for the following permanent strengthening. Test results show that: (a) for the joints of shield tunnel’s neighboring segments, the strengthening method can effectively reduce the joint opening, joint deflection, concrete strain in joint’s compression zone, and strain of joint’s steel bolts; (b) the revised electric heating method can be used to heat the SMA rod to a temperature higher than the SMA’s austenite finish temperature quickly, and the average heating rate related to Type 2 inner resistance element is larger than that related to Type 1 inner resistance element; and (c) the reduction percentages of the joint opening increment, joint deflection, concrete strain in joint’s compression zone, and strain of joint’s steel bolts for Specimen I are all larger than those for Specimen II, implying that the less the joint opening is, the more significant the strengthening effect is.

  10. Review on Cold-Formed Steel Connections

    PubMed Central

    Tan, Cher Siang; Mohammad, Shahrin; Md Tahir, Mahmood; Shek, Poi Ngian

    2014-01-01

    The concept of cold-formed light steel framing construction has been widespread after understanding its structural characteristics with massive research works over the years. Connection serves as one of the important elements for light steel framing in order to achieve its structural stability. Compared to hot-rolled steel sections, cold-formed steel connections perform dissimilarity due to the thin-walled behaviour. This paper aims to review current researches on cold-formed steel connections, particularly for screw connections, storage rack connections, welded connections, and bolted connections. The performance of these connections in the design of cold-formed steel structures is discussed. PMID:24688448

  11. Review on cold-formed steel connections.

    PubMed

    Lee, Yeong Huei; Tan, Cher Siang; Mohammad, Shahrin; Tahir, Mahmood Md; Shek, Poi Ngian

    2014-01-01

    The concept of cold-formed light steel framing construction has been widespread after understanding its structural characteristics with massive research works over the years. Connection serves as one of the important elements for light steel framing in order to achieve its structural stability. Compared to hot-rolled steel sections, cold-formed steel connections perform dissimilarity due to the thin-walled behaviour. This paper aims to review current researches on cold-formed steel connections, particularly for screw connections, storage rack connections, welded connections, and bolted connections. The performance of these connections in the design of cold-formed steel structures is discussed.

  12. Review on cold-formed steel connections.

    PubMed

    Lee, Yeong Huei; Tan, Cher Siang; Mohammad, Shahrin; Tahir, Mahmood Md; Shek, Poi Ngian

    2014-01-01

    The concept of cold-formed light steel framing construction has been widespread after understanding its structural characteristics with massive research works over the years. Connection serves as one of the important elements for light steel framing in order to achieve its structural stability. Compared to hot-rolled steel sections, cold-formed steel connections perform dissimilarity due to the thin-walled behaviour. This paper aims to review current researches on cold-formed steel connections, particularly for screw connections, storage rack connections, welded connections, and bolted connections. The performance of these connections in the design of cold-formed steel structures is discussed. PMID:24688448

  13. Analysis of OH Bolted Ear Connection

    SciTech Connect

    Wands, Bob; /Fermilab

    1987-12-30

    The D0 endcap calorimeter outer hadronic (OH) modules play a major structural role in the calorimeter assembly. The disrete modules, once connected together, form a ring within which other massive calorimetry will reside. It has been proposed that the connection of the OH at the downstream end be accomplished by extending the downstream endplates in the radial direction to form 'ears', and then through-bolting between adjacent ears as shown in Fig. 1. A single 2 1/4 in. dia. bolt is used, and previous calculations have determined that the design load on this joint should be 130,000 lbs tension. The high load and serious consequences of failure make this a critical component in the calorimeter assembly. The purpose of this analysis is to investigate the stresses in the connection and other mechanical characteristics which determine joint performance.

  14. Failure analyses of composite bolted joints

    NASA Technical Reports Server (NTRS)

    Wilson, D. W.; Gillespie, J. W.; York, J. L.; Pipes, R. B.

    1980-01-01

    The complex failure behavior exhibited by bolted joints of graphite epoxy (Hercules AS/3501) was investigated for the net tension, bearing and shearout failure modes using combined analytical and experimental techniques. Plane stress, linear elastic, finite element methods were employed to determine the two dimensional state of stress resulting from a loaded hole in a finite width, semiinfinite strip. The stresses predicted by the finite element method were verified by experiment to lend credence to the analysis. The influence of joint geometric parameters on the state of stress and resultant strength of the joint was also studied. The resulting functional relationships found to exist between bolted joint strength and the geometric parameters, were applied in the formulation of semiempirical strength models for the basic failure modes. A point stress failure criterion was successfully applied as the failure criterion for the net tension and shearout failure modes.

  15. An interview with Bruce A. Bolt

    USGS Publications Warehouse

    Spall, H.

    1987-01-01

    Professor Bruce Bolt was educated in Australia and first came to the United States in 1960 on a Fulbright Fellowship to the Lamont Geological Observatory of Columbia University. In 1963 he was appointed Director of the Seismographic Stations at the University of California at Berkeley. In June 1988, he steps down as Director but his association will continue as Professor of Seismology. Henry Spall interviewed him again 10 years after a 977 interview published in the Earthquake Information Bulletin. 

  16. Finite element analysis of bolted flange connections

    NASA Astrophysics Data System (ADS)

    Hwang, D. Y.; Stallings, J. M.

    1994-06-01

    A 2-D axisymmetric finite element model and a 3-D solid finite element model of a high pressure bolted flange joint were generated to investigate the stress behaviors. This investigation includes comparisons for axisymmetric loading of both the 2-D and 3-D models, the effects of non-axisymmetric bolt pretensions in the 3-D models, and the differences between 2-D and 3-D models subjected to non-axisymmetric loading. Comparisons indicated differences in von Mises stress up to 12% at various points due to the non-axisymmetric bolt pretensions. Applied bending moments were converted to equivalent axial forces for use in the 2-D model. It was found that the largest von Mises stresses in 3-D model did not occur on the side of the connection where the bending stresses and applied axial stresses were additive. Hence, in the 2-D model where the equivalent axial force (for bending moment) and applied axial forces were added, the 2-D model under estimated the maximum von Mises stress obtained from the 3-D model by 30%.

  17. Strain measurements in composite bolted-joint specimens

    NASA Technical Reports Server (NTRS)

    Hyer, M. W.; Lightfoot, M. C.; Perry, J. C.

    1979-01-01

    Strain data from a series of bolted joint tests is presented. Double lap, double hole, double lap, single hole, and open hole tensile specimens were tested and the strain gage locations, load strain responses, and load axial displacement responses are presented. The open hole specimens were gaged to determine strain concentration factors. The double lap, double hole specimens were gaged to determine the uniformity of the strain in the joint and the amount of load transferred past the first bolt. The measurements indicated roughly half the load passed the first bolt to be reacted by the second bolt.

  18. External Tank (ET) Bipod Fitting Bolted Attachment Locking Insert Performance

    NASA Technical Reports Server (NTRS)

    Larsen, Curtis E.; Wilson, Tim R.; Elliott, Kenny B.; Raju, Ivatury S.; McManamen, John

    2008-01-01

    Following STS-107, the External Tank (ET) Project implemented corrective actions and configuration changes at the ET bipod fitting. Among the corrective actions, the existing bolt lock wire which provided resistance to potential bolt rotation was removed. The lock wire removal was because of concerns with creating voids during foam application and potential for lock wire to become debris. The bolts had been previously lubricated to facilitate assembly but, because of elimination of the lock wire, the ET Project wanted to enable the locking feature of the insert. Thus, the lubrication was removed from bolt threads and instead applied to the washer under the bolt head. Lubrication is necessary to maximize joint pre-load while remaining within the bolt torque specification. The locking feature is implemented by thread crimping in at four places in the insert. As the bolt is torqued into the insert the bolt threads its way past the crimped parts of the insert. This provides the locking of the bolt, as torque is required to loosen the joint after clamping.

  19. Evaluations of a noise control for roof bolting machines

    PubMed Central

    Azman, A.S.; Yantek, D.S.; Alcorn, L.A.

    2015-01-01

    In collaboration with Kennametal Inc. and Corry Rubber Corporation, the U.S. National Institute for Occupational Safety and Health (NIOSH) developed a drill bit isolator to address noise overexposures associated with roof bolting machines in underground coal mines. NIOSH laboratory studies confirmed that the drill bit isolator reduces noise during drilling. Field studies were needed to confirm that a noise reduction could be obtained under working conditions and that the device was sufficiently durable. This paper reports results of field tests of the device conducted at five underground coal mines. Noise reduction was assessed by comparing the operator’s noise exposure during drilling with and without the drill bit isolator. Durability was assessed by recording the number of holes and total feet drilled with each bit isolator until either the test period ended or the device failed. The results from these tests showed that the device is an effective noise control in a mine environment. The field-tested drill bit isolators provided a noise reduction of 3–5 dB(A). Of nine devices tested for durability, five exceeded 610 m (2,000 ft) drilled and two exceeded 762 m (2,500 ft) drilled before failure. Durability issues found in the field tests led to final production optimizations that have resulted in a commercially available product for drilling with 35-mm- (1.3-in.-) diameter roof bits and hexagonal drill steels. PMID:26251555

  20. Rock bolt certification tests in salt, Eddy County, New Mexico

    SciTech Connect

    Stewart, R.M.

    1981-11-01

    One hundred rock bolts were installed and tested in the Kerr-McGee potash mine near Carlsbad, New Mexico. The bolts were installed in salt, then instrumented and loaded to failure. The failure modes for tensile tests were expansion shell slippage in salt or polyester resin slippage in salt. The failure modes for shear tests were a combination of bending and shearing or breaking of the bolts near the shear plate-salt interface. Safety factors are not included in the bolt loads in the report. Grade 75 (75,000 psi yield strength) rock bolts with 5/8- and 3/4-in. diameters were stressed into the yield region during tensile and shear tests with 1-3/8-in.-diam by 3-in. expansion shells. The theoretical yield load was 17,000 lb for 5/8-in. bolts and 25,000 lb for 3/4-in. bolts. One-inch-diameter bolts could not be adequately anchored with a single expansion shell to provide yielding. The average anchorage for all bolts moved 1.38 in. before reaching a maximum load of 27,000 lb. Grade 60 (60,000 psi yield strength) deformed reinforcing bar bolts, 1-in. diameter were stressed into the computed yield region approximately 47,000 lb during tensile tests. Yielding was accomplished with polyester resin anchorage when 2 or more resin cartridges (1-1/4 in. by 12 in.) were used. In shear tests, Grade 60 threaded rebar bolts, 1-in. diam, anchored with polyester resin, bent and broke at an average shear force of 34,200 lb with a displacement of 0.52 in.

  1. Bolted Double-Lap Composite Joints Under Mechanical and Thermal Loading

    NASA Technical Reports Server (NTRS)

    Kradinov, V.; Barut, A.; Madenci, E.; Walker, Sandra P. (Technical Monitor)

    2000-01-01

    This study concerns the determination of the contact stresses and contact region around bolt holes and the bolt load distribution in single- and double-lap joints of composite laminates with arbitrarily located bolts under general mechanical loading conditions and uniform temperature change. The unknown contact stress distribution and contact region between the bolt and laminates and the interaction among the bolts require the bolt load distribution, as well as the contact stresses, to be as part of the solution. The present method is based on the complex potential theory and the variational formulation in order to account for bolt stiffness, bolt-hole clearance, and finite geometry of the composite laminates.

  2. 46 CFR 56.90-5 - Bolting procedure.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Bolting procedure. 56.90-5 Section 56.90-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING PIPING SYSTEMS AND APPURTENANCES Assembly § 56.90-5 Bolting procedure. (a) All flanged joints shall be fitted up so that the...

  3. 15. DETAIL OF ANCHOR BOLT WHICH FORMERLY SECURED A TIMBER ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    15. DETAIL OF ANCHOR BOLT WHICH FORMERLY SECURED A TIMBER SILL BEAM TO THE GRANITE SILL ALONG THE EASTERLY EDGE OF THE SPILLWAY APRON (NOTE 3" SWISS ARMY KNIFE TO RIGHT OF BOLT FOR SCALE); VIEW TO WEST. - Blackstone Canal Millbury Segment, Beginning northwest of State Route 146 & McCracken Road, running along west side of Route 146, Millbury, Worcester County, MA

  4. Structural analysis of closure bolts for shipping casks

    SciTech Connect

    Mok, G.C.; Fischer, L.E.

    1993-04-01

    This paper identifies the active forces and moments in a closure bolt of a shipping cask. It examines the interactions of these forces/moments and suggest simplified methods for their analysis. The paper also evaluates the role that the forces and moments play in the structure integrity of the closure bolt and recommends stress limits and desirable practices to ensure its integrity.

  5. 33. Three bolts on railing outside control house on north ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    33. Three bolts on railing outside control house on north tower, one bolt on first handrail post of the north span (bridge is in the open position). As the bridge opens or closes the single bolt on the handrail post moves past the three stationary bolts. This system is used by the bridge operator to judge speed and position of the north span as it opens or closes. Based on these bolts movement of the north span is speeded up or slowed down and the brakes applied during the opening and closing process. View facing east. - Henry Ford Bridge, Spanning Cerritos Channel, Los Angeles-Long Beach Harbor, Los Angeles, Los Angeles County, CA

  6. The Broadband Observatory for the Localization of Transients (BOLT)

    NASA Astrophysics Data System (ADS)

    Craig, W.; Helfand, D.; Kahn, S.; Kamionkowski, M.; Paerels, F. B.; Cook, W.; Harrison, F.; Kulkarni, S.; Metzger, M.; Prince, T.; Schindler, S.; Thorsett, S.; Paczynski, B.; Cook, K.; Ziock, K.; Thompson, S.

    1997-12-01

    The Broadband Observatory for Localization of Transients (BOLT) is a Small Explorer mission to study the origins of gamma-ray bursts. BOLT will provide a burst sensitivity improved an order of magnitude over BATSE, arcsecond burst astrometry, broadband energy coverage (5 keV -- 1 MeV), realtime (< 3 minute) burst notification and localization, high sensitivity to cyclotron lines, wide FOV, and will telemeter all data to the ground. Over its mission life, BOLT will provide ~ 500 bursts with positins accurate enough for counterpart IDs and over 1000 bursts for detailed study. BOLT will also survey the entire hard X-ray sky to flux levels a factor 50 -- 100 lower that HEAO A-4. In this poster, we present an overview of the mission science goals and instrumentation, and describe the vigorous education and public outreach program that will convey BOLT's discoveries to the public.

  7. Simulating the Structural Response of a Preloaded Bolted Joint

    NASA Technical Reports Server (NTRS)

    Knight, Norman F., Jr.; Phillips, Dawn R.; Raju, Ivatury S.

    2008-01-01

    The present paper describes the structural analyses performed on a preloaded bolted-joint configuration. The joint modeled was comprised of two L-shaped structures connected together using a single bolt. Each L-shaped structure involved a vertical flat segment (or shell wall) welded to a horizontal segment (or flange). Parametric studies were performed using elasto-plastic, large-deformation nonlinear finite element analyses to determine the influence of several factors on the bolted-joint response. The factors considered included bolt preload, washer-surface-bearing size, edge boundary conditions, joint segment length, and loading history. Joint response is reported in terms of displacements, gap opening, and surface strains. Most of the factors studied were determined to have minimal effect on the bolted-joint response; however, the washer-bearing-surface size affected the response significantly.

  8. The supersymmetric NUTs and bolts of holography

    NASA Astrophysics Data System (ADS)

    Martelli, Dario; Passias, Achilleas; Sparks, James

    2013-11-01

    We show that a given conformal boundary can have a rich and intricate space of supersymmetric supergravity solutions filling it, focusing on the case where this conformal boundary is a biaxially squashed Lens space. Generically we find that the biaxially squashed Lens space S3/Zp admits Taub-NUT-AdS fillings, with topology R4/Zp, as well as smooth Taub-Bolt-AdS fillings with non-trivial topology. We show that the Taub-NUT-AdS solutions always lift to solutions of M-theory, and correspondingly that the gravitational free energy then agrees with the large N limit of the dual field theory free energy, obtained from the localized partition function of a class of N=2 Chern-Simons-matter theories. However, the solutions of Taub-Bolt-AdS type only lift to M-theory for appropriate classes of internal manifold, meaning that these solutions exist only for corresponding classes of three-dimensional N=2 field theories. This result should be contrasted with the corresponding situation for asymptotically locally Euclidean metrics, where Killing vector fields on the boundary do not necessarily extend inside. The canonical examples are the Gibbons-Hawking multi-centre solutions [29].

  9. Epigenomics and bolting tolerance in sugar beet genotypes.

    PubMed

    Hébrard, Claire; Peterson, Daniel G; Willems, Glenda; Delaunay, Alain; Jesson, Béline; Lefèbvre, Marc; Barnes, Steve; Maury, Stéphane

    2016-01-01

    In sugar beet (Beta vulgaris altissima), bolting tolerance is an essential agronomic trait reflecting the bolting response of genotypes after vernalization. Genes involved in induction of sugar beet bolting have now been identified, and evidence suggests that epigenetic factors are involved in their control. Indeed, the time course and amplitude of DNA methylation variations in the shoot apical meristem have been shown to be critical in inducing sugar beet bolting, and a few functional targets of DNA methylation during vernalization have been identified. However, molecular mechanisms controlling bolting tolerance levels among genotypes are still poorly understood. Here, gene expression and DNA methylation profiles were compared in shoot apical meristems of three bolting-resistant and three bolting-sensitive genotypes after vernalization. Using Cot fractionation followed by 454 sequencing of the isolated low-copy DNA, 6231 contigs were obtained that were used along with public sugar beet DNA sequences to design custom Agilent microarrays for expression (56k) and methylation (244k) analyses. A total of 169 differentially expressed genes and 111 differentially methylated regions were identified between resistant and sensitive vernalized genotypes. Fourteen sequences were both differentially expressed and differentially methylated, with a negative correlation between their methylation and expression levels. Genes involved in cold perception, phytohormone signalling, and flowering induction were over-represented and collectively represent an integrative gene network from environmental perception to bolting induction. Altogether, the data suggest that the genotype-dependent control of DNA methylation and expression of an integrative gene network participate in bolting tolerance in sugar beet, opening up perspectives for crop improvement.

  10. Epigenomics and bolting tolerance in sugar beet genotypes

    PubMed Central

    Hébrard, Claire; Peterson, Daniel G.; Willems, Glenda; Delaunay, Alain; Jesson, Béline; Lefèbvre, Marc; Barnes, Steve; Maury, Stéphane

    2016-01-01

    In sugar beet (Beta vulgaris altissima), bolting tolerance is an essential agronomic trait reflecting the bolting response of genotypes after vernalization. Genes involved in induction of sugar beet bolting have now been identified, and evidence suggests that epigenetic factors are involved in their control. Indeed, the time course and amplitude of DNA methylation variations in the shoot apical meristem have been shown to be critical in inducing sugar beet bolting, and a few functional targets of DNA methylation during vernalization have been identified. However, molecular mechanisms controlling bolting tolerance levels among genotypes are still poorly understood. Here, gene expression and DNA methylation profiles were compared in shoot apical meristems of three bolting-resistant and three bolting-sensitive genotypes after vernalization. Using Cot fractionation followed by 454 sequencing of the isolated low-copy DNA, 6231 contigs were obtained that were used along with public sugar beet DNA sequences to design custom Agilent microarrays for expression (56k) and methylation (244k) analyses. A total of 169 differentially expressed genes and 111 differentially methylated regions were identified between resistant and sensitive vernalized genotypes. Fourteen sequences were both differentially expressed and differentially methylated, with a negative correlation between their methylation and expression levels. Genes involved in cold perception, phytohormone signalling, and flowering induction were over-represented and collectively represent an integrative gene network from environmental perception to bolting induction. Altogether, the data suggest that the genotype-dependent control of DNA methylation and expression of an integrative gene network participate in bolting tolerance in sugar beet, opening up perspectives for crop improvement. PMID:26463996

  11. A bolt out of the blue.

    PubMed

    Dwyer, Joseph R

    2005-05-01

    Lightning is a particularly unsettling product of bad weather. It causes more deaths and injuries in the U.S. than either hurricanes or tornadoes do, and it strikes without warning, sometimes with nothing but blue sky overhead. In central Florida, where I live, thunderstorms are a daily occurrence during the summer, and so, ironically, people in the Sunshine State often spend their afternoons indoors to avoid the risk of death from the sky. Worldwide, lightning flashes about four million times a day, and bolts have even been observed on other planets. Yet despite its familiarity, we still do not know what causes lightning. It is a misconception that Benjamin Franklin solved the puzzle when he conducted his famous kite experiment in 1752. PMID:15882023

  12. A bolt out of the blue.

    PubMed

    Dwyer, Joseph R

    2005-05-01

    Lightning is a particularly unsettling product of bad weather. It causes more deaths and injuries in the U.S. than either hurricanes or tornadoes do, and it strikes without warning, sometimes with nothing but blue sky overhead. In central Florida, where I live, thunderstorms are a daily occurrence during the summer, and so, ironically, people in the Sunshine State often spend their afternoons indoors to avoid the risk of death from the sky. Worldwide, lightning flashes about four million times a day, and bolts have even been observed on other planets. Yet despite its familiarity, we still do not know what causes lightning. It is a misconception that Benjamin Franklin solved the puzzle when he conducted his famous kite experiment in 1752.

  13. Explosive Bolt Dual-Initiated from One Side

    NASA Technical Reports Server (NTRS)

    Snow, Eric

    2011-01-01

    An explosive bolt has been developed that has a one-sided dual initiation train all the way down to the pyro charge for high reliability, while still allowing the other side of the bolt to remain in place after actuation to act as a thermal seal in an extremely high-temperature environment. This lightweight separation device separates at a single fracture plane, and has as much redundancy/reliability as possible. The initiation train comes into the explosive bolt from one side.

  14. Easing The Calculation Of Bolt-Circle Coordinates

    NASA Technical Reports Server (NTRS)

    Burley, Richard K.

    1995-01-01

    Bolt Circle Calculation (BOLT-CALC) computer program used to reduce significant time consumed in manually computing trigonometry of rectangular Cartesian coordinates of holes in bolt circle as shown on blueprint or drawing. Eliminates risk of computational errors, particularly in cases involving many holes or in cases in which coordinates expressed to many significant digits. Program assists in many practical situations arising in machine shops. Written in BASIC. Also successfully compiled and implemented by use of Microsoft's QuickBasic v4.0.

  15. What Makes Usain Bolt Unique as a Sprinter?

    NASA Astrophysics Data System (ADS)

    Shinabargar, A. J.; Hellrich, Matt; Baker, Blane

    2010-09-01

    For both casual and avid fans alike, Olympic and other sporting events can provide a wealth of data for simple physics analyses. One of the most impressive performances in recent Olympic history is that of Usain Bolt in the track-and-field sprinting events during the 2008 Summer Games. Over a seven-day span, Bolt set world records in the 100-m and 200-m individual sprints and in the 4 × 100-m sprint relay. In addition, Bolt left us all wondering what record time he might have run had he not eased into the finish line in the 100-m dash. Naturally, one question many fans and observers immediately ask is: What makes Usain Bolt unique as a sprinter?

  16. Mechanics of Re-Torquing in Bolted Flange Connections

    NASA Technical Reports Server (NTRS)

    Gordon, Ali P.; Drilling Brian; Weichman, Kyle; Kammerer, Catherine; Baldwin, Frank

    2010-01-01

    It has been widely accepted that the phenomenon of time-dependent loosening of flange connections is a strong consequence of the viscous nature of the compression seal material. Characterizing the coupled interaction between gasket creep and elastic bolt stiffness has been useful in predicting conditions that facilitate leakage. Prior advances on this sub-class of bolted joints has lead to the development of (1) constitutive models for elastomerics, (2) initial tightening strategies, (3) etc. The effect of re-torque, which is a major consideration for typical bolted flange seals used on the Space Shuttle fleet, has not been fully characterized, however. The current study presents a systematic approach to characterizing bolted joint behavior as the consequence of sequentially applied torques. Based on exprimenta1 and numerical results, the optimal re-torquing parameters have been identified that allow for the negligible load loss after pre-load application

  17. Preloading of bolted connections in nuclear reactor component supports

    SciTech Connect

    Yahr, G T

    1984-10-01

    A number of failures of threaded fasteners in nuclear reactor component supports have been reported. Many of those failures were attributed to stress corrosion cracking. This report discusses how stress corrosion cracking can be avoided in bolting by controlling the maximum bolt preloads so that the sustained stresses in the bolts are below the level required to cause stress corrosion cracking. This is a basic departure from ordinary bolted joint design where the only limits on preload are on the minimum preload. Emphasis is placed on the importance of detailed analysis to determine the acceptable range of preload and the selection of a method for measuring the preload that is sufficiently accurate to ensure that the preload is actually within the acceptable range. Procedures for determining acceptable preload range are given, and the accuracy of various methods of measuring preload is discussed.

  18. 2. DETAIL VIEW SHOWING BOLTED KNEE BRACES ON AFRAME OF ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. DETAIL VIEW SHOWING BOLTED KNEE BRACES ON A-FRAME OF WALKING BEAM ENGINE. Photocopy of photograph. Susan Kardas, photographer, November 1984 - Shooters Island, Ships Graveyard, Vessel No. 53, Newark Bay, Staten Island (subdivision), Richmond County, NY

  19. 7. VIEW OF WORKER DEBARKING CEDAR BOLT; LARRY L. LESTER ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    7. VIEW OF WORKER DEBARKING CEDAR BOLT; LARRY L. LESTER (RIGHT); WORKERS WHO EXECUTE THIS DEBARKING ARE CALLED KNEEBOLTERS; WILLIAM C. MARKERT (MIDDLE) IS A SHINGLE WEAVER WHO SAWS SHINGLES FROM THE FACE OF THE CEDAR BOLT AFTER DEBARKING, THEN CLIPS EACH SHINGLE IN THE LAST STEP BEFORE SENDING IT TO THE CHECKER AND BUNDLER - Lester Shingle Mill, 1602 North Eighteenth Street, Sweet Home, Linn County, OR

  20. EVA assembly and release of highly loaded bolts

    NASA Technical Reports Server (NTRS)

    Olmstead, Jim; Barker, Paul

    1996-01-01

    The modification of a multi-jackbolt mechanism, Superbolt(TM), for on-orbit release of highly loaded bolts is described. Preload and release test data demonstrate that modification of a commercial product produced a solution for the deployment of the Space Station Remote Manipulator System (SSRMS) that was less expensive, faster, and lighter than other alternatives. Using the Superbolt design, virtually unlimited bolt loads can be applied or released with a standard wrench.

  1. What Makes Usain Bolt Unique as a Sprinter?

    ERIC Educational Resources Information Center

    Shinabargar, A. J.; Hellrich, Matt; Baker, Blane

    2010-01-01

    For both casual and avid fans alike, Olympic and other sporting events can provide a wealth of data for simple physics analyses. One of the most impressive performances in recent Olympic history is that of Usain Bolt in the track-and-field sprinting events during the 2008 Summer Games. Over a seven-day span, Bolt set world records in the 100-m and…

  2. Nickel alloy stud bolts failure: A case history

    SciTech Connect

    Toffolo, G.; Fassina, P.; Marangoni, M.; Msallem, A.

    1996-12-01

    High strength and corrosion resistance material as Inconel X-750 has been selected for the seal flange bolts in an off-shore field in Libya, due to its properties at high temperature, needed for compliance with Fire Safe requirements. After 4 years from the production start-up, during a routine maintenance of wellheads, some bolts have been found cracked. The paper deals with all the activities done in order to understand the cause of the failure. In particular failure analysis has been carried out through laboratory investigation, and shop tests have been conducted to confirm the field procedure and determine the tension on the bolts during the installation. The main conclusion was that the bolts failed due to the concurrence of stress (over-torque that means stress level higher than yield one) and corrosion (pit/crevice conditions). This environmentally assisted failure is known as Hydrogen Embrittlement (HE). Test carried out using the same X-mas tree mounted on the platform justifies the assumption that in the field, where the conditions are far from the ideal, it is possible that even when a uniform torque is set, the tensile stress applied to the bolts is not uniform, making the situation critical. From the corrosion side, the failed bolts showed some corrosion points near the cracks, as due to environment in the crevice/pitting conditions required to justify the hydrogen presence (the bolts are not cathodically protected). Fatigue has been demonstrated not to be responsible for the failure. Solutions are recommended which can safely be adopted during the installation and the substitution of bolts on an existing wellhead, which is operative under pressure without shutting in the well, and not impairing the safety operating envelope.

  3. Effect of bolting on roadway support in extremely weak rock.

    PubMed

    Li, Qinghai; Shi, Weiping; Qin, Zhongcheng

    2016-01-01

    In mine roadway support operations, floor bolting not only played a role in floor heave control, but also in reinforcing roof and its two sides. Correspondingly, bolting of roof and two sides also played a part in floor heave control. To quantify the effect of such bolting, based on roadway support in extremely weak rock, three physical models were produced and tested in laboratory. Through comparison of their displacements in three physical simulation experiments, the reinforcing effect of bolting in extremely weak rock roadways was quantified. Reinforcing coefficients was defined as displacement ratio between original support and new support regime. Results indicated that the reinforcing coefficients, for bolting of roof and its two sides, on floor, two sides, and roof reached 2.18, 3.56, and 1.81 respectively. The reinforcing coefficients for floor bolting on floor, two sides, and roof reached 3.06, 2.34, and 1.39 respectively. So in this extremely weak rock, the surrounding rock should be considered as an integral structure in any support operation: this allows for better local strength improvement, and provided future design guidance.

  4. Effect of bolting on roadway support in extremely weak rock.

    PubMed

    Li, Qinghai; Shi, Weiping; Qin, Zhongcheng

    2016-01-01

    In mine roadway support operations, floor bolting not only played a role in floor heave control, but also in reinforcing roof and its two sides. Correspondingly, bolting of roof and two sides also played a part in floor heave control. To quantify the effect of such bolting, based on roadway support in extremely weak rock, three physical models were produced and tested in laboratory. Through comparison of their displacements in three physical simulation experiments, the reinforcing effect of bolting in extremely weak rock roadways was quantified. Reinforcing coefficients was defined as displacement ratio between original support and new support regime. Results indicated that the reinforcing coefficients, for bolting of roof and its two sides, on floor, two sides, and roof reached 2.18, 3.56, and 1.81 respectively. The reinforcing coefficients for floor bolting on floor, two sides, and roof reached 3.06, 2.34, and 1.39 respectively. So in this extremely weak rock, the surrounding rock should be considered as an integral structure in any support operation: this allows for better local strength improvement, and provided future design guidance. PMID:27588248

  5. Guideline for bolted joint design and analysis : version 1.0.

    SciTech Connect

    Brown, Kevin H.; Morrow, Charles W.; Durbin, Samuel; Baca, Allen

    2008-01-01

    This document provides general guidance for the design and analysis of bolted joint connections. An overview of the current methods used to analyze bolted joint connections is given. Several methods for the design and analysis of bolted joint connections are presented. Guidance is provided for general bolted joint design, computation of preload uncertainty and preload loss, and the calculation of the bolted joint factor of safety. Axial loads, shear loads, thermal loads, and thread tear out are used in factor of safety calculations. Additionally, limited guidance is provided for fatigue considerations. An overview of an associated Mathcad{copyright} Worksheet containing all bolted joint design formulae presented is also provided.

  6. Ultrasonic Method for Deployment Mechanism Bolt Element Preload Verification

    NASA Technical Reports Server (NTRS)

    Johnson, Eric C.; Kim, Yong M.; Morris, Fred A.; Mitchell, Joel; Pan, Robert B.

    2014-01-01

    Deployment mechanisms play a pivotal role in mission success. These mechanisms often incorporate bolt elements for which a preload within a specified range is essential for proper operation. A common practice is to torque these bolt elements to a specified value during installation. The resulting preload, however, can vary significantly with applied torque for a number of reasons. The goal of this effort was to investigate ultrasonic methods as an alternative for bolt preload verification in such deployment mechanisms. A family of non-explosive release mechanisms widely used by satellite manufacturers was chosen for the work. A willing contractor permitted measurements on a sampling of bolt elements for these release mechanisms that were installed by a technician following a standard practice. A variation of approximately 50% (+/- 25%) in the resultant preloads was observed. An alternative ultrasonic method to set the preloads was then developed and calibration data was accumulated. The method was demonstrated on bolt elements installed in a fixture instrumented with a calibrated load cell and designed to mimic production practice. The ultrasonic method yielded results within +/- 3% of the load cell reading. The contractor has since adopted the alternative method for its future production. Introduction

  7. Optimizing Piezoelectric Stack Preload Bolts in Ultrasonic Transducers

    NASA Astrophysics Data System (ADS)

    DeAngelis, D. A.; Schulze, G. W.; Wong, K. S.

    The selection of the preload bolt is often an afterthought in the design of Langevin type "sandwich" transducers, but quite often it is the root cause of failure for power ultrasonic applications. The main role of the preload bolt is to provide a "prestress" in the piezo stack to prevent interface "gapping" or tension in glued joints which can result in delamination. But as an integral part of a highly tuned dynamic system, the resulting parasitic resonances in these preload bolts, such as bending or longitudinal modes, are often difficult to predict and control. This research investigates many aspects of preload bolt design for achieving optimal transducer performance, including basic size and strength determination based on drive amplitude, as well as ensuring adequate thread engagement to the mating horn. Other aspects such as rule-of-thumb configuration and length guidelines to reduce parasitic resonances are also investigated. Optimizing the uniformity of stress in the piezoceramics is also considered, which is affected by end mass length, counterbores and proximity to threading. The selection of the bolt material based on stiffness is also investigated as related to electromechanical coupling. The investigation focuses solely on Langevin type transducers used for semiconductor wire bonding, and which are comprised of the common Navy Types I and III (PZT4 and PZT8) piezoelectric materials. Several metrics are investigated such as impedance, displacement gain, and electromechanical coupling factor. The experimental and theoretical research methods include Bode plots, scanning laser vibrometry and finite element analysis.

  8. Bolt-bearing fatigue of a graphite/epoxy laminate

    NASA Technical Reports Server (NTRS)

    Crews, J. H., Jr.

    1980-01-01

    Graphite/epoxy laminates were tested under bolt-bearing loads for a range of bolt clampup torques and for several test conditions involving water. High clampup torque improved both the static strength and fatigue limit by about 100 percent compared to a simple pin-bearing case, which had no through-the-thickness constraint. The static strength improvement was explained in terms of failure modes. Bolt clampup also influenced the hole elongation that developed before failure. For both the static and fatigue tests, the hole elongations were much larger for the low-torque clampup. Tests in water degraded static bearing strength only slightly, but reduced the fatigue limit about 40 percent below that for tests conducted in air.

  9. High-speed plasma imaging: A lightning bolt

    SciTech Connect

    Wurden, G.A.; Whiteson, D.O.

    1996-02-01

    Using a gated intensified digital Kodak Ektapro camera system, the authors captured a lightning bolt at 1,000 frames per second, with 100-{micro}s exposure time on each consecutive frame. As a thunder storm approaches while darkness descended (7:50 pm) on July 21, 1994, they photographed lightning bolts with an f22 105-mm lens and 100% gain on the intensified camera. This 15-frame sequence shows a cloud to ground stroke at a distance of about 1.5 km, which has a series of stepped leaders propagating downwards, following by the upward-propagating main return stroke.

  10. Characterization of an Unusual Cytoplasmic Chimera Detected in Bolting Garlic (Allium sativum L.) Clones

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Production of a visible flower stalk or bolting has been used as a major trait to categorize garlic clones. Analysis of mitochondrial genome variation with PCR revealed differences between bolting and non-bolting clones of garlic. Screening 333 garlic accessions from diverse geographic origins rev...

  11. Ultrasonic measurement and monitoring of loads in bolts used in structural joints

    NASA Astrophysics Data System (ADS)

    Koshti, Ajay M.

    2015-04-01

    The paper is an overview of work by the author in measuring and monitoring loads in bolts using an ultrasonic extensometer. A number of cases of bolted joints are covered. These include, a clamped joint with clearance fit between the bolt and hole, a clamped joint with bolt in an interference fit with the hole, a flanged joint which allows the flange and bolt to bend; and a shear joint in a clevis and tang configuration. These applications were initially developed for measuring and monitoring preload in National Aeronautics and Space Administration (NASA) Space Shuttle Orbiter critical joints but are also applicable for monitoring loads in other critical bolted joints of structures such as transportation bridges and other aerospace structures. The papers cited here explain how to set-up a model to estimate the ultrasonic load factor and accuracy for the ultrasonic preload application in a clamped joint with clearance fit. The ultrasonic preload application for clamped joint with bolt in an interference fit can also be used to measure diametrical interference between the bolt shank and hole, as well as interference pressure on the bolt shank. Results of simulation and experimental data are given to demonstrate use of ultrasonic measurements in a shear joint. A bolt in a flanged joint experiences both tensile and bending loads. This application involves measurement of bending and tensile preload in a bolt. The ultrasonic beam bends due to bending load on the bolt. Results of a numerical technique to compute the trace of ultrasonic ray are presented.

  12. NASA's Radio Frequency Bolt Monitor: A Lifetime of Spinoffs

    NASA Technical Reports Server (NTRS)

    2005-01-01

    This story begins in the 1970s, when Dr. Joseph Heyman, a young scientist at NASA s Langley Research Center, was asked to support the investigation of a wind tunnel accident at a sister center. Although the work was outside of his physics background, it sparked a research focus that guided his lengthy NASA career and would earn him a slew of accolades, including NASA s highest award medals for Exceptional Leadership, Exceptional Achievement, and Exceptional Service; the coveted Silver Snoopy Astronaut Award for Space Shuttle Return to Flight; and the Arthur Fleming Award for being one of the Top Ten Federal Scientists in Government Service. He won 30 additional NASA awards, including the Agency s Invention of the Year and the Agency s highest award for technology transfer, and was the only person to ever win 4 R&D 100 Awards. Back in 1973, though, Heyman was a young civil servant with a background in physics who was asked to sit on an accident review panel. The panel met at Ames Research Center, in Moffet Field, California, and after considerable investigation, concluded that a high-pressure pebble heater used for heating gas had failed, due to improperly tightened bolts in a 1,000-pound gate valve control section. The accident showered the facility with incendiary ceramic spheres and nearly a ton of metal, but, luckily, caused no injuries. Heyman returned to Langley and began work on a solution. He developed an ultrasonic device that would measure bolt elongation, as opposed to torque, the factor typically measured in testing bolt preload or tension. Torque measurement can lead to load errors, with miscalculations as high as 80 percent that can be passed over during installation. Bolt stretch, however, is nearly always accurate to 1 percent or better. Within 1 month, he had an acoustic resonance solution that accurately determined bolt elongation. He assumed his work on this project had ended, but it was actually the start of nearly 15 years of work perfecting

  13. A survey of EMS-induced biennial Beta vulgaris mutants reveals a novel bolting locus which is unlinked to the bolting gene B.

    PubMed

    Büttner, Bianca; Abou-Elwafa, Salah F; Zhang, Wenying; Jung, Christian; Müller, Andreas E

    2010-10-01

    Beta vulgaris is a facultative perennial species which exhibits large intraspecific variation in vernalization requirement and includes cultivated biennial forms such as the sugar beet. Vernalization requirement is under the genetic control of the bolting locus B on chromosome II. Previously, ethyl methanesulfonate (EMS) mutagenesis of an annual accession had yielded several mutants which require vernalization to bolt and behave as biennials. Here, five F2 populations derived from crosses between biennial mutants and annual beets were tested for co-segregation of bolting phenotypes with genotypic markers located at the B locus. One mutant appears to be mutated at the B locus, suggesting that an EMS-induced mutation of B can be sufficient to abolish annual bolting. Co-segregation analysis in four populations indicates that the genetic control of bolting also involves previously unknown major loci not linked to B, one of which also affects bolting time and was genetically mapped to chromosome IX.

  14. Evaluation of Roof Bolting Requirements Based on In-Mine Roof Bolter Drilling

    SciTech Connect

    Syd S. Peng

    2005-10-01

    Roof bolting is the most popular method for underground openings in the mining industry, especially in the bedded deposits such as coal. In fact, all U.S. underground coal mine entries are roof-bolted as required by law. However, roof falls still occur frequently in the roof bolted entries. The two possible reasons are: the lack of knowledge of and technology to detect the roof geological conditions in advance of mining, and lack of roof bolting design criteria for modern roof bolting systems. This research is to develop a method for predicting the roof geology and stability condition in real time during roof bolting operation. Based on this information, roof bolting design criteria for modern roof bolting systems will be developed for implementation in real time. For the prediction of roof geology and stability condition in real time, a micro processor was used and a program developed to monitor and record the drilling parameters of roof bolter. These parameters include feed pressure, feed flow (penetration rate), rotation pressure, rotation rate, vacuum pressure, oil temperature of hydraulic circuit, and signals for controlling machine. From the results of a series of laboratory and underground tests so far, feed pressure is found to be a good indicator for identifying the voids/fractures and estimating the roof rock strength. The method for determining quantitatively the location and the size of void/fracture and estimating the roof rock strength from the drilling parameters of roof bolter was developed. Also, a set of computational rules has been developed for in-mine roof using measured roof drilling parameters and implemented in MRGIS (Mine Roof Geology Information System), a software package developed to allow mine engineers to make use of the large amount of roof drilling parameters for predicting roof geology properties automatically. For the development of roof bolting criteria, finite element models were developed for tensioned and fully grouted bolting

  15. Electrical Conductance of Bolted Copper Joints for Cryogenic Applications

    NASA Astrophysics Data System (ADS)

    Blondelle, F.; Sultan, A.; Collin, E.; Godfrin, H.

    2014-06-01

    We present the results of electric contact resistance measurements at low temperatures on copper-to-copper bolted joints. Our accurate and systematic data display a rather small dispersion, and may be a useful tool for cryogenic applications like pulse-tubes, dilution refrigerators and nuclear refrigerators.

  16. A novel ultrasonic method to quantify pressure in bolted joints

    NASA Astrophysics Data System (ADS)

    Sisman, A.; Martinez, J.; Guldiken, R.

    2012-12-01

    In structures most of fasteners are not critical for rigidity, however significant damage can occur if majority of uncritical fasteners fail. Furthermore, the maintenance is not feasible due to their vast quantity. In this study, we explored a new method to significantly improve the maintenance capability for these fasteners. The method distantly detects the preload between the bolt and the surface. We use a linear transducer array that generates acoustic beam using surface acoustic waves (SAWs) transmitted by array elements. The bolt boundary reflects SAW and array elements receive the echo signals. The signals are processed in the beamformer to generate the boundary's image which quantifies the preload to enable a strong estimation about the health of the bolted joint. We experimentally investigated the proposed method by using used a 5-MHz, 50-elements synthetic array. We measured the preload for five different tightening levels. As expected, two saturation regions (for too tightening and too loosening cases) and a linear region are observed (between them). The electronically steering of the array enables to make simultaneous preload measurements of many bolted joints in the same surface. The distant pressure measurement sensor could be integrated to a data acquisition system to track the health of the joints over time.

  17. DETAIL OF BOLTS IMBEDDED IN THE TOP OF THE WEST ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    DETAIL OF BOLTS IMBEDDED IN THE TOP OF THE WEST PROTRUDING ARM OF THE TABLE-LIKE CAST CONCRETE STRUCTURE. VIEW FACING SOUTHWEST - U.S. Naval Base, Pearl Harbor, Ford Island 5-Inch Antiaircraft Battery, East Gun Emplacement, Ford Island, Pearl City, Honolulu County, HI

  18. Majorana Demonstrator Bolted Joint Mechanical and Thermal Analysis

    SciTech Connect

    Aguayo Navarrete, Estanislao; Reid, Douglas J.; Fast, James E.

    2012-06-01

    The MAJORANA DEMONSTRATOR is designed to probe for neutrinoless double-beta decay, an extremely rare process with a half-life in the order of 1026 years. The experiment uses an ultra-low background, high-purity germanium detector array. The germanium crystals are both the source and the detector in this experiment. Operating these crystals as ionizing radiation detectors requires having them under cryogenic conditions (below 90 K). A liquid nitrogen thermosyphon is used to extract the heat from the detectors. The detector channels are arranged in strings and thermally coupled to the thermosyphon through a cold plate. The cold plate is joined to the thermosyphon by a bolted joint. This circular plate is housed inside the cryostat can. This document provides a detailed study of the bolted joint that connects the cold plate and the thermosyphon. An analysis of the mechanical and thermal properties of this bolted joint is presented. The force applied to the joint is derived from the torque applied to each one of the six bolts that form the joint. The thermal conductivity of the joint is measured as a function of applied force. The required heat conductivity for a successful experiment is the combination of the thermal conductivity of the detector string and this joint. The thermal behavior of the joint is experimentally implemented and analyzed in this study.

  19. Apparatus For Eddy-Current Inspection Of Bolts

    NASA Technical Reports Server (NTRS)

    Amos, Jay M.

    1994-01-01

    Eddy-current apparatus for inspection of bolts, studs, and other threaded fasteners detects flaws in threads, shanks, and head fillets. With help of apparatus, technician quickly inspects fasteners of various dimensions. Accommodates fasteners with diameters from 0.190 in. to 1 in. and with lengths up to 5 in. Basic design modified to accommodate fasteners of other sizes.

  20. 9 CFR 313.15 - Mechanical; captive bolt.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... instruments on detonation deliver bolts of varying diameters and lengths through the skull and into the brain. Unconsciousness is produced immediately by physical brain destruction and a combination of changes in intracranial... a flattened circular head against the external surface of the animal's head over the brain....

  1. 9 CFR 313.15 - Mechanical; captive bolt.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... instruments on detonation deliver bolts of varying diameters and lengths through the skull and into the brain. Unconsciousness is produced immediately by physical brain destruction and a combination of changes in intracranial... a flattened circular head against the external surface of the animal's head over the brain....

  2. 9 CFR 313.15 - Mechanical; captive bolt.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... instruments on detonation deliver bolts of varying diameters and lengths through the skull and into the brain. Unconsciousness is produced immediately by physical brain destruction and a combination of changes in intracranial... a flattened circular head against the external surface of the animal's head over the brain....

  3. Trestle #1, detail of connecting bolts and spikes on upper ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Trestle #1, detail of connecting bolts and spikes on upper northeast abutment. View to east - Promontory Route Railroad Trestles, S.P. Trestle 779.91, One mile southwest of junction of State Highway 83 and Blue Creek, Corinne, Box Elder County, UT

  4. Trestle #1, detail of bolt and washer on wing wall ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Trestle #1, detail of bolt and washer on wing wall on north west side of northeast abutment. View to northeast - Promontory Route Railroad Trestles, S.P. Trestle 779.91, One mile southwest of junction of State Highway 83 and Blue Creek, Corinne, Box Elder County, UT

  5. 16. STRUCTURAL DETAILS: CHANNEL, BIT & CLEAT, ANCHOR BOLTS & ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    16. STRUCTURAL DETAILS: CHANNEL, BIT & CLEAT, ANCHOR BOLTS & PLATES FOR PIERS 4, 5, AND 6, DWG. NO. 97, 1-1/2" = 1', MADE BY A.F., JUNE 13, 1908 - Baltimore Inner Harbor, Pier 5, South of Pratt Street between Market Place & Concord Street, Baltimore, Independent City, MD

  6. 9 CFR 313.15 - Mechanical; captive bolt.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... air devices must be equipped to deliver the necessary constant air pressure and must have accurate, constantly operating air pressure gauges. Gauges must be easily read and conveniently located for use by the... pressure and acceleration concussion. Nonpenetrating or mushroom stunners on detonation deliver a bolt...

  7. 9 CFR 313.15 - Mechanical; captive bolt.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... air devices must be equipped to deliver the necessary constant air pressure and must have accurate, constantly operating air pressure gauges. Gauges must be easily read and conveniently located for use by the... pressure and acceleration concussion. Nonpenetrating or mushroom stunners on detonation deliver a bolt...

  8. A Simulation of Optimal Foraging: The Nuts and Bolts Approach.

    ERIC Educational Resources Information Center

    Thomson, James D.

    1980-01-01

    Presents a mechanical model for an ecology laboratory that introduces the concept of optimal foraging theory. Describes the physical model which includes a board studded with protruding machine bolts that simulate prey, and blindfolded students who simulate either generalist or specialist predator types. Discusses the theoretical model and data…

  9. Development of Rock Bolt Elements in Two-Dimensional Discontinuous Deformation Analysis

    NASA Astrophysics Data System (ADS)

    Nie, W.; Zhao, Z. Y.; Ning, Y. J.; Sun, J. P.

    2014-11-01

    Computer modeling can be used to explore and gain new insights into the impacts of rock bolt intersecting joints in rock masses, and to estimate the effectiveness of the rock reinforcement system. In order to achieve this goal, we couple a rock bolt element into the two-dimensional discontinuous deformation analysis (DDA2D) program. The coupling algorithm is based on the analytically-derived interface behavior between a rock bolt and the rock material for grouted rock bolts. The shear force generated by slippage along the interface is assumed to have a linear relationship with respect to the relative slipping distance between the rock bolt and the rock. The linear elastic criterion is applied to determine the material behavior of rock bolts before the axial stress reaches the yield value. The pullout tests are simulated to verify the coupling algorithm and the effects of the proposed rock bolt elements. Parametrical studies are also carried out to analyze the effectiveness of the rock bolts under various end conditions, joint locations and bond stiffness. In addition, the performance of the rock bolt during the interface debonding is analyzed using two types of constitutive laws, i.e., the friction law and the reduction law. The simulation results show that the proposed rock bolt models can predict the shear forces and axial loading along the rock bolts.

  10. A Novel RFID-Based Sensing Method for Low-Cost Bolt Loosening Monitoring.

    PubMed

    Wu, Jian; Cui, Xingmei; Xu, Yunpeng

    2016-01-01

    In coal mines, bolt loosening in the cage guide is affected by the harsh environmental factors and cage hoist vibration, leading to significant threats to work safety. It is crucial, to this effect, to successfully detect the status of multipoint bolts of guide structures. This paper proposes a system to monitor bolt status in harsh environments established based on the RFID technique. A proof-of-concept model was demonstrated consisting of a bolt gearing system, passive UHF RFID tags, a reader, and monitoring software. A tinfoil metal film is fixed on the retaining plate and an RFID tag bonded to a large gear, with the bolt to be detected fixed in the center of a smaller gear. The radio-frequency signal cannot be received by the reader if the tag is completely obscured by the tinfoil, and if the bolt is loose, the tag's antenna is exposed when the gear revolves. A radio-frequency signal that carries corresponding bolt's information is transmitted by the RFID tag to the RFID reader due to coil coupling, identifying loose bolt location and reporting them in the software. Confirmatory test results revealed that the system indeed successfully detects bolt loosening and comparative test results (based on a reed switch multipoint bolt loosening monitor system) provided valuable information regarding the strengths and weaknesses of the proposed system. PMID:26828498

  11. Improving the selection of bolted joint parameters by using results from finite-element analysis

    SciTech Connect

    Ziada, H.H.

    1992-10-01

    Finite-element techniques were used to determine the combination of parameters that would produce the optimum design for the bolted joint. A finite-element model was constructed from a combination of two-dimensional isoparametric axisymmetric solid elements and gap elements. The gap elements represented the physical contact between the plate and bolt head and the plate and nut. The model was used to determine the stress patterns, displacements, and contact areas (separation diameters) across the bolted joint. Computed results for the contact area showed the following: the contact area is determined by joint design, not bolt Toad magnitude; joint thickness, plate thickness ratio, and bolt-head dimensions have a pronounced effect on the contact area; and the maximum contact area occurs with plates of equal thickness. The change in separation diameters (D) can be presented in a simple straight-line expression D/d = 1 + 1.1 (L/d), where L = joint thickness and d = bolt diameter. The stress results indicated that neither load nor stress distribution under the bolt head or nut is constant or uniform. Bolt-head dimensions, joint thickness, and plate thickness ratio markedly affect the developed stresses, with the maximum stress value occurring at the bolt-plate interface. Beyond the bolt head, maximum stress develops at the interface plane of the bolted plates, with that stress decreasing as the plate thickness ratio increases reaching its lowest value at the equal-thickness ratio. These results indicate that design stiffness formulas used heretofore are not adequate. Results provided by this analysis should prove more effective in achieving optimum bolt design for bolted joints.

  12. Ballistics Analysis of Orion Crew Module Separation Bolt Cover

    NASA Technical Reports Server (NTRS)

    Howard, Samuel A.; Konno, Kevin E.; Carney, Kelly S.; Pereira, J. Michael

    2013-01-01

    NASA is currently developing a new crew module to replace capabilities of the retired Space Shuttles and to provide a crewed vehicle for exploring beyond low earth orbit. The crew module is a capsule-type design, which is designed to separate from the launch vehicle during launch ascent once the launch vehicle fuel is expended. The separation is achieved using pyrotechnic separation bolts, wherein a section of the bolt is propelled clear of the joint at high velocity by an explosive charge. The resulting projectile must be contained within the fairing structure by a containment plate. This paper describes an analytical effort completed to augment testing of various containment plate materials and thicknesses. The results help guide the design and have potential benefit for future similar applications.

  13. Demonstration of a Pyrotechnic Bolt-Retractor System

    NASA Technical Reports Server (NTRS)

    Johnston, Nick; Ahmed, Rafiq; Garrison, Craig; Gaines, Joseph; Waggoner, Jason

    2004-01-01

    A paper describes a demonstration of the X-38 bolt-retractor system (BRS) on a spacecraft-simulating apparatus, called the Large Mobility Base, in NASA's Flight Robotics Laboratory (FRL). The BRS design was proven safe by testing in NASA's Pyrotechnic Shock Facility (PSF) before being demonstrated in the FRL. The paper describes the BRS, FRL, PSF, and interface hardware. Information on the bolt-retraction time and spacecraft-simulator acceleration, and an analysis of forces, are presented. The purpose of the demonstration was to show the capability of the FRL for testing of the use of pyrotechnics to separate stages of a spacecraft. Although a formal test was not performed because of schedule and budget constraints, the data in the report show that the BRS is a successful design concept and the FRL is suitable for future separation tests.

  14. Development of New Stainless Steel

    SciTech Connect

    Robert F. Buck

    2005-08-30

    A new family of innovative martensitic stainless steels, 521-A, 521-B, and 521-C has been developed by Advanced Steel Technology, LLC (Trafford, PA) as high strength fastener (bolt) materials for use at moderate temperatures in turbine engines, including steam turbines, gas turbines, and aircraft engines. The primary objective of the development program was to create a martensitic stainless steel with high strength at moderate temperatures, and which could replace the expensive nickel-based superalloy IN 718 in some fasteners applications. A secondary objective was to replace conventional 12Cr steels such as AISI 422 used as blades, buckets and shafts that operate at intermediate temperatures in turbine engines with stronger steel. The composition of the new alloys was specifically designed to produce excellent mechanical properties while integrating heat treatment steps into production to reduce energy consumption during manufacturing. As a result, production costs and energy consumption during production of rolled bar products is significantly lower than conventional materials. Successful commercialization of the new alloys would permit the installed cost of certain turbine engines to be reduced without sacrificing high availability or operational flexibility, thereby enhancing the global competitiveness of U.S. turbine engine manufacturers. Moreover, the domestic specialty steel industry would also benefit through increased productivity and reduced operating costs, while increasing their share of the international market for turbine engine fasteners, blades, buckets and shafts.

  15. Standard Methods for Bolt-Bearing Testing of Textile Composites

    NASA Technical Reports Server (NTRS)

    Portanova, M. A.; Masters, J. E.

    1995-01-01

    The response of three 2-D braided materials to bolt bearing loading was evaluated using data generated by Boeing Defense and Space Group in Philadelphia, PA. Three test methods, stabilized single shear, unstabilized single shear, and double shear, were compared. In general, these textile composites were found to be sensitive to bolt bearing test methods. The stabilized single shear method yielded higher strengths than the unstabilized single shear method in all cases. The double shear test method always produced the highest strengths but these results may be somewhat misleading. It is therefore recommended that standard material comparisons be made using the stabilized single shear test method. The effects of two geometric parameters, W/D and e/D, were also studied. An evaluation of the effect of the specimen width (W) to hole diameter (D) ratio concluded that bolt bearing responses were consistent with open hole tension results. A W/D ratio of 6 or greater should be maintained. The proximity of the hole to the specimen edge significantly affected strength. In all cases, strength was improved by increasing the ratio of the distance from the hole center to the specimen edge (e) to the hole diameter (D) above 2. An e/D ratio of 3 or greater is recommended.

  16. Experimental study of friction in aluminium bolted joints

    NASA Astrophysics Data System (ADS)

    Croccolo, D.; de Agostinis, M.; Vincenzi, N.

    2010-06-01

    This study aims at developing an experimental tool useful to define accurately the friction coefficients in bolted joints and, therefore, at relating precisely the tightening torque to the bolt preloading force in some special components used in front motorbike suspensions. The components under investigation are some clamped joints made of aluminium alloy. The preloading force is achieved by applying a torque wrench to the bolt head. Some specific specimens have been appropriately designed and realized in order to study the tribological aspects of the tightening phase. Experimental tests have been performed by applying the Design of Experiment (DOE) method in order to obtain a mathematical model for the friction coefficients. Three replicas of a full factorial DOE at two levels for each variable have been carried out. The levels include cast versus forged aluminium alloy, anodized versus spray-painted surface, lubricated versus unlubricated screw, and first tightening (fresh unspoiled surfaces) versus sixth tightening (spoiled surfaces). The study considers M8x1.25 8.8 galvanized screws.

  17. Stress relaxation of high strength A-286 bolts in simulated storage at room temperature

    NASA Technical Reports Server (NTRS)

    Sampson, R. C.

    1972-01-01

    It was concluded that thermally activated relaxation of the type customarily encountered at high temperatures was not expected to occur at the low temperatures where long time NERVA storage conditions will prevail. Instances where relaxation occurred by a different mechanism at such moderate temperatures were also reported. Twelve simulated bolted flange test specimens were prepared. Parameters that were varied among the twelve specimens were the flange material, the bolt shank diameter, and the bolt loading in terms of percent of yield strength.

  18. Improved wire stiffness with modified connection bolts in Ilizarov external frames: a biomechanical study.

    PubMed

    Gessmann, Jan; Jettkant, Birger; Königshausen, Matthias; Schildhauer, Thomas Armin; Seybold, Dominik

    2012-01-01

    Frame stability in Ilizarov external fixators is mainly dependent on the tension of the transosseous wires, which are clamped to the ring by connection bolts. It was the purpose of this biomechanical study to investigate the holding capacity of a modified bolt design featuring a ruffled wire-bolt interface (TrueLok™) and its influence on wire stiffness in comparison with that of classic bolts featuring a smooth, unruffled wire-bolt interface. Six different ring and bolt configurations were tested using a simplified model consisting of a single ring and wire. The holding capacity at two different tightening torques (10 and 14 Nm) of classic cannulated bolts (CB) and slotted bolts (SB) was determined on Ilizarov and Taylor Spatial Frame (TSF™) rings, whereas the modified TrueLok™ CBs and SBs were used with the TrueLok™ rings. The wire stiffness was calculated via a regression analysis of the load-displacement graphs. The modified TrueLok™ bolts demonstrated significantly better slippage resistance than the classic bolts in all configurations and wire stiffness was significantly higher in the TrueLok™ frame set-ups. After maximum loading, all of the wires showed plastic deformation, including constant wire deflection and dent marks at the clamped wire ends. In conclusion, the decrease in wire stiffness can be explained mainly as a result of wire slippage, but plastic deformation and material yielding also contribute. The relatively simple modification made by roughening the wire-bolt interface results in improved holding capacity and wire stiffness. A frame that contains these modified TrueLok™ bolts should provide improved mechanical stiffness.

  19. Improved wire stiffness with modified connection bolts in Ilizarov external frames: a biomechanical study.

    PubMed

    Gessmann, Jan; Jettkant, Birger; Königshausen, Matthias; Schildhauer, Thomas Armin; Seybold, Dominik

    2012-01-01

    Frame stability in Ilizarov external fixators is mainly dependent on the tension of the transosseous wires, which are clamped to the ring by connection bolts. It was the purpose of this biomechanical study to investigate the holding capacity of a modified bolt design featuring a ruffled wire-bolt interface (TrueLok™) and its influence on wire stiffness in comparison with that of classic bolts featuring a smooth, unruffled wire-bolt interface. Six different ring and bolt configurations were tested using a simplified model consisting of a single ring and wire. The holding capacity at two different tightening torques (10 and 14 Nm) of classic cannulated bolts (CB) and slotted bolts (SB) was determined on Ilizarov and Taylor Spatial Frame (TSF™) rings, whereas the modified TrueLok™ CBs and SBs were used with the TrueLok™ rings. The wire stiffness was calculated via a regression analysis of the load-displacement graphs. The modified TrueLok™ bolts demonstrated significantly better slippage resistance than the classic bolts in all configurations and wire stiffness was significantly higher in the TrueLok™ frame set-ups. After maximum loading, all of the wires showed plastic deformation, including constant wire deflection and dent marks at the clamped wire ends. In conclusion, the decrease in wire stiffness can be explained mainly as a result of wire slippage, but plastic deformation and material yielding also contribute. The relatively simple modification made by roughening the wire-bolt interface results in improved holding capacity and wire stiffness. A frame that contains these modified TrueLok™ bolts should provide improved mechanical stiffness. PMID:23394181

  20. Numerical Studies on Time-Varying Stiffness of Disk-Drum Type Rotor with Bolt Loosening

    NASA Astrophysics Data System (ADS)

    Qin, Zhaoye; Chu, Fulei

    2015-07-01

    Disk-drum type rotors are widely used in industry for their high stiffness and low weight properties. In disk-drum type rotors, the adjacent disks and drums are commonly connected by bolted joints. Those rotating joint interfaces are subjected to numerous combinations of loads during normal operation, where loosening of the connecting bolts might occur. The bolt loosening will change the local stiffness of the rotor, which in turn affect the rotor dynamics and even result in structural failures. In this paper, the local stiffness of a disk- drum rotor with bolt loosening is investigated numerically. A three-dimensional (3D) finite element (FE) model for the bolted disk-drum joint is established in ANSYS, where the bolt loosening is simulated by reducing the preloads of certain bolts, and removing those bolts as the limiting case. Simulations are performed on the FE model to evaluate the joint behaviour under static loads. Periodic variations of the joint deflections with respect to the rotation angle of the shaft are obtained, which implies the appearance of the time-varying local stiffness in the rotor system. The studies in this paper help accurate prediction of the rotor dynamics and early detection of bolt loosening.

  1. A Novel RFID-Based Sensing Method for Low-Cost Bolt Loosening Monitoring

    PubMed Central

    Wu, Jian; Cui, Xingmei; Xu, Yunpeng

    2016-01-01

    In coal mines, bolt loosening in the cage guide is affected by the harsh environmental factors and cage hoist vibration, leading to significant threats to work safety. It is crucial, to this effect, to successfully detect the status of multipoint bolts of guide structures. This paper proposes a system to monitor bolt status in harsh environments established based on the RFID technique. A proof-of-concept model was demonstrated consisting of a bolt gearing system, passive UHF RFID tags, a reader, and monitoring software. A tinfoil metal film is fixed on the retaining plate and an RFID tag bonded to a large gear, with the bolt to be detected fixed in the center of a smaller gear. The radio-frequency signal cannot be received by the reader if the tag is completely obscured by the tinfoil, and if the bolt is loose, the tag’s antenna is exposed when the gear revolves. A radio-frequency signal that carries corresponding bolt’s information is transmitted by the RFID tag to the RFID reader due to coil coupling, identifying loose bolt location and reporting them in the software. Confirmatory test results revealed that the system indeed successfully detects bolt loosening and comparative test results (based on a reed switch multipoint bolt loosening monitor system) provided valuable information regarding the strengths and weaknesses of the proposed system. PMID:26828498

  2. Installation and safety practices for cable bolts in underground mines. Information circular/1996

    SciTech Connect

    Martin, L.A.; Girard, J.M.; Goris, J.M.

    1995-12-01

    Flexible tendons, or cable bolts, have been recognized as an effective and efficient support system for underground mines. In the past 10 years, use of cable bolts has increased substantially. Two of the most significant safety hazards associated with cable bolts are the dissipation of stored energy in cable coils and the failure of cable anchors. The U.S. Bureau of Mines has documented these hazards, as well as other possible hazards associated with handling and installing cable bolts, and has evaluated potential solution.

  3. Antiloosening ability of 5/8 inch stainless steel BSW threaded fasteners

    NASA Astrophysics Data System (ADS)

    Panja, Bikash; Das, Santanu

    2016-07-01

    Threaded fasteners are popular for temporary joining of different components due to the fact that they retain high clamping force and torque for long. However, they may loosen under vibrating conditions causing failure of the system. In this experimental work, antiloosening ability of various 5/8 inch BSW fastening elements, such as conventional nut and nylock nut with flat washer, spring washer, inside and outside serrated washers is tested with stainless steel (SS) bolts. A hybrid double nut using a simple nut and one nylock nut at the outside and a typical adhesive bonded nut with 5/8 inch BSW bolt are introduced to obtain resistance to loosening. Some hybrid double nut and adhesive bonded nut are recommended for stainless steel 5/8 inch BSW bolts under vibration.

  4. Isolation and identification of an anti-bolting compound, hexadecatrienoic acid monoglyceride, responsible for inhibition of bolting and maintenance of the leaf rosette in radish plants.

    PubMed

    Yoshida, Yuko; Takada, Noboru; Koda, Yasunori

    2010-08-01

    Generally, the bolting (stem elongation from rosette plants) of winter annuals is believed to be induced by an increase in the levels of gibberellin that occurs after a certain period of chilling (vernalization), and a deficiency of gibberellin allows the plant to maintain a rosette style. Lack of direct evidence proving the above assumption in radish plants (Raphanus sativus L.) encouraged us to assume the presence of an anti-bolting compound actively maintaining the rosette habit through inhibition of bolting. Anti-bolting activity was detected in an extract of rosette shoots of radish plants by an assay using seedlings cultured in vitro. The causal compound that strongly inhibited bolting was isolated and identified as alpha-(7Z,10Z,13Z)-hexadecatrienoic acid monoglyceride (16:3 monoglyceride). This compound did not inhibit leaf production at the apical meristem, indicating that it merely inhibits growth at the internode. The compound disappeared completely after vernalization, and bolting occurred thereafter. The results suggest that the release from inhibition by 16:3 monoglyceride induces the initiation of bolting. The possible mechanism by which the compound exerts the activity is discussed. PMID:20601431

  5. Effectiveness of poll stunning water buffalo with captive bolt guns.

    PubMed

    Gregory, N G; Spence, J Y; Mason, C W; Tinarwo, A; Heasman, L

    2009-01-01

    Practical experience has indicated that shooting water buffalo with a captive bolt gun in the front of the head does not always produce an effective stun. Slaughtermen have been claiming that the poll position is more reliable, but under present EU regulations this shooting position is not allowed for domesticated bovines. This study examined the effectiveness of shooting water buffalo with captive bolt guns in the poll region. The depth of concussion was assessed in 30 water buffalo from physical collapse, presence or absence of corneal and palpebral reflexes, normal rhythmic breathing, eyeball rotation, nystagmus and whether the animal was re-shot. All except one animal collapsed immediately. The one animal that failed to collapse was not breathing. The prevalence of a shallow depth of concussion in the poll shot animals was 53%. Two had been shot through the spinal cord, and with the exception of those plus one other in which the bolt did not penetrate the brain, the other animals were considered to be adequately stunned. Post mortem examination of the brain showed that 79% of the under thirty month old animals were shot in the midbrain or brain stem, but these regions had to be avoided in over thirty month old animals because of the risk of damaging the brain stem sample needed for BSE testing. In addition, three water buffalo were shot in the crown position and one in the front of the head. The frontal position was ineffective as the animal did not collapse, and all animals shot in the crown position resumed breathing shortly after shooting, indicating a shallow depth of concussion. It is concluded that poll shooting can be effective in water buffalo, but it produces a shallow depth of concussion compared with frontal shooting in cattle. It requires accurate placement of the gun to ensure that buffalo are not shot through the spinal cord instead of the brain. Vigilance is needed in ensuring that the animals are stuck promptly so that none recover consciousness.

  6. Heating and cooling gas-gun targets: nuts and bolts

    SciTech Connect

    Gustavsen, Richard L; Bartram, Brian D; Gehr, Russell J; Bucholtz, Scott M

    2009-01-01

    The nuts and bolts of a system used to heat and cool gas-gun targets is described. We have now used the system for more than 35 experiments, all of which have used electromagnetic gauging. Features of the system include a cover which is removed (remotely) just prior to projectile impact and the widespread use of metal/polymer insulations. Both the cover and insulation were required to obtain uniform temperatures in samples with low thermal conductivity. The use of inexpensive video cameras to make remote observations of the cover removal was found to be very useful. A brief catalog of useful glue, adhesive tape, insulation, and seal materials is given.

  7. Mapping of quantitative trait loci for the bolting trait in Brassica rapa under vernalizing conditions.

    PubMed

    Wang, Y G; Zhang, L; Ji, X H; Yan, J F; Liu, Y T; Lv, X X; Feng, H

    2014-01-01

    Premature bolting can occur occasionally during spring cultivation of heading Chinese cabbage in East Asia when the plants encounter low temperatures (vernalization), leading to economic loss. Breeding bolting-resistant cultivars is the best choice for solving this problem. We looked for QTLs responsible for varietal differences in the bolting trait in Brassica rapa under environmental conditions that promote vernalization. To achieve this goal, we constructed a linkage map with 107 simple sequence repeats and 54 insertion/deletion markers based on a segregating population of 186 F2 individuals. The resulting map consisted of 10 linkage groups and covered a total length of 947.1 cM, with an average genetic distance of 5.84 cM between adjacent markers. QTL analysis of the bolting trait was performed by two phenotypic evaluations (bolting index and flowering time) based on the scores in an F2 population in the spring of 2010, and scores in F2:3 families in autumn 2010 and spring 2011, respectively. Twenty-six QTLs that controlled bolting were detected, accounting for 2.6 to 31.2% of the phenotypic variance. The detected QTLs with large effects co-localized mainly on linkage groups A02, A06, and A07. These QTLs may provide useful information for marker-assisted selection in a breeding program for late bolting or bolting-resistant cultivars in B. rapa crops.

  8. The Nuts and Bolts of Michaelis-Menten Enzyme Kinetics: Suggestions and Clarifications

    ERIC Educational Resources Information Center

    Silverstein, Todd

    2011-01-01

    Matthew Junker's recent article describes a useful and effective enzyme kinetics application and analogy in which students simulate enzyme activity by unscrewing nut-bolt "substrate molecules", thus, converting them into separate nuts and bolts "products". A number of suggestions and corrections are presented that improve the clarity and accuracy…

  9. Unilateral buckling of elastically restrained rectangular mild steel plates

    NASA Astrophysics Data System (ADS)

    Smith, S. T.; Bradford, M. A.; Oehlers, D. J.

    This paper considers the elastic unilateral buckling of rectangular mild steel plates that are restrained elastically and subjected to bending and axial actions. A variational formulation of the Ritz method using linear combinations of harmonic functions for the buckling deformations is used to establish an eigenproblem to determine the plate local buckling coefficients. The motivation for the study is the retrofit of reinforced concrete beams by gluing and then bolting steel plates to the sides of the beam. Such plates, when acting compositely with the concrete beam, are subjected to predominantly bending and axial actions which may cause unilateral local buckling. Whereas the bolts provide complete restraint against buckling at discrete points, the glue may also inhibit local buckling between these nodal points since it acts as a continuous elastic restraint. The influence of the glue stiffness, support conditions and plate proportions on the unilateral buckling of such plates are assessed.

  10. Design and analysis of lid closure bolts for packages used to transport radioactive materials

    SciTech Connect

    Raske, D.T.; Stojimirovic, A.

    1995-07-01

    The design criterion recommended by the U.S. Department of Energy for Category I radioactive packaging is found in Section III, Division 1, of the ASME Boiler and Pressure Vessel Code. This criterion provides material specifications and allowable stress limits for bolts used to secure lids of containment vessels. This paper describes the design requirements for Category I containment vessel lid closure bolts, and provides an example of a bolting stress analysis. The lid-closure bolting stress analysis compares calculations based on handbook formulas with an analysis performed with a finite-element computer code. The results show that the simple handbook calculations can be sufficiently accurate to evaluate the bolt stresses that occur in rotationally rigid lid flanges designed for metal-to-metal contact.

  11. EVALUATION OF TROQUE VS CLOSURE BOLT PRELOAD FOR A TYPICAL CONTAINMENT VESSEL UNDER SERVICE CONDITIONS

    SciTech Connect

    Smith, A.

    2010-02-16

    Radioactive material package containment vessels typically employ bolted closures of various configurations. Closure bolts must retain the lid of a package and must maintain required seal loads, while subjected to internal pressure, impact loads and vibration. The need for insuring that the specified preload is achieved in closure bolts for radioactive materials packagings has been a continual subject of concern for both designers and regulatory reviewers. The extensive literature on threaded fasteners provides sound guidance on design and torque specification for closure bolts. The literature also shows the uncertainty associated with use of torque to establish preload is typically between 10 and 35%. These studies have been performed under controlled, laboratory conditions. The ability to insure required preload in normal service is, consequently, an important question. The study described here investigated the relationship between indicated torque and resulting bolt load for a typical radioactive materials package closure using methods available under normal service conditions.

  12. Performance of bolted closure joint elastomers under cask aging conditions

    SciTech Connect

    Verst, C.; Sindelar, R.; Skidmore, E.; Daugherty, W.

    2015-07-23

    The bolted closure joint of a bare spent fuel cask is susceptible to age-related degradation and potential loss of confinement function under long-term storage conditions. Elastomeric seals, a component of the joint typically used to facilitate leak testing of the primary seal that includes the metallic seal and bolting, is susceptible to degradation over time by several mechanisms, principally via thermo-oxidation, stress-relaxation, and radiolytic degradation under time and temperature condition. Irradiation and thermal exposure testing and evaluation of an ethylene-propylene diene monomer (EPDM) elastomeric seal material similar to that used in the CASTOR® V/21 cask for a matrix of temperature and radiation exposure conditions relevant to the cask extended storage conditions, and development of semiempirical predictive models for loss of sealing force is in progress. A special insert was developed to allow Compressive Stress Relaxation (CSR) measurements before and after the irradiation and/or thermal exposure without unloading the elastomer. A condition of the loss of sealing force for the onset of leakage was suggested. The experimentation and modeling being performed could enable acquisition of extensive coupled aging data as well as an estimation of the timeframe when loss of sealing function under aging (temperature/radiation) conditions may occur.

  13. Twofold hidden conformal symmetry of Kerr Bolt black holes

    NASA Astrophysics Data System (ADS)

    Setare, M. R.; Kamali, V.

    2012-02-01

    Previously we have shown that a four-dimensional Kerr—Bolt black hole in non-extremal and also in extremal cases could be described by a holographic two-dimensional (2D) conformal field theory (CFT) [Ghezelbash A M, Kamali V and Setare M R 2010 Phys. Rev. D 82 124051; Setare M R and Kamali V 2010 JHEP 10 074]. Motivated by recent work [Chen C M, Huang Y M, Sun J R, Wu M F and Zou S J 2010 Phys. Rev. D 82 066004], we show that there is another holographic description for these black holes. The first description is called the J-picture, whose construction is based on the black hole angular momentum. The new description is called the Q-picture, whose constructions originate from the nut charge of the black hole. Similar to the previous cases [Ghezelbash A M, Kamali V and Setare M R 2010 Phys. Rev. D 82 124051; Setare M R and Kamali V 2010 JHEP 10 074], we show that this new picture for a low frequency limit of the wave equation of a massless charged scalar field in the background of a Kerr—Bolt black hole can be written as the Casimir of SL(2, R) symmetry. Our result shows that the entropy of the black hole is reproduced by the Cardy formula. In addition, the absorption cross section is consistent with the finite temperature absorption cross section for a two-dimensional CFT.

  14. Device for measuring hole elongation in a bolted joint

    NASA Technical Reports Server (NTRS)

    Wichorek, Gregory R. (Inventor)

    1987-01-01

    A device to determine the operable failure mode of mechanically fastened lightweight composite joints by measuring the hole elongation of a bolted joint is disclosed. The double-lap joint test apparatus comprises a stud, a test specimen having a hole, two load transfer plates, and linear displacement measuring instruments. The test specimen is sandwiched between the two load transfer plates and clamped together with the stud. Spacer washers are placed between the test specimen and each load transfer plate to provide a known, controllable area for the determination of clamping forces around the hole of the specimen attributable to bolt torque. The spacer washers also provide a gap for the mounting of reference angles on each side of the test specimen. Under tensile loading, elongation of the hole of the test specimen causes the stud to move away from the reference angles. This displacement is measured by the voltage output of two linear displacement measuring instruments that are attached to the stud and remain in contact with the reference angles throughout the tensile loading. The present invention obviates previous problems in obtaining specimen deformation measurements by monitoring the reference angles to the test specimen and the linear displacement measuring instruments to the stud.

  15. Health monitoring of bolted joints using the time reversal method and piezoelectric transducers

    NASA Astrophysics Data System (ADS)

    Tao, Wang; Shaopeng, Liu; Junhua, Shao; Yourong, Li

    2016-02-01

    In this paper, the time reversal method based on piezoelectric active sensing is investigated for health monitoring of bolted joints. Experiments are conducted on bolted joints to study the relationship between the time reversal focused signal peak amplitudes and the bolt preload. Two piezoelectric patches are bonded on two different sides of a bolted joint. Any one of the piezoelectric patches can be used as an actuator to generate an ultrasonic wave, and the other one can be used as a sensor to detect the propagated wave. With the time reversal method, the received response signal is reversed in the time domain and then is re-emitted as an excitation signal to acquire the time reversal focused signals. The experimental results show that the time reversal focused signal peak amplitudes increase with the increasing bolt preload until reaching saturation, and when the bolt preload increases to a certain value, the focused signal peak amplitudes will remain unchanged. Experiments show that the surface roughness of the bolted joint impacts the saturation value. A higher surface roughness value corresponds to a higher saturation value. In addition, the proposed method has a high signal to noise ratio benefiting from the time reversal method time and space focusing ability.

  16. Experimental determination of satellite bolted joints thermal resistance

    NASA Technical Reports Server (NTRS)

    Mantelli, Marcia Barbosa Henriques; Basto, Jose Edson

    1990-01-01

    The thermal resistance was experimentally determined of the bolted joints of the first Brazilian satellite (SCD 01). These joints, used to connect the satellite structural panels, are reproduced in an experimental apparatus, keeping, as much as possible, the actual dimensions and materials. A controlled amount of heat is forced to pass through the joint and the difference of temperature between the panels is measured. The tests are conducted in a vacuum chamber with liquid nitrogen cooled walls, that simulates the space environment. Experimental procedures are used to avoid much heat losses, which are carefully calculated. Important observations about the behavior of the joint thermal resistance with the variation of the mean temperature are made.

  17. Test and analytical results of a new bolt configuration for a diagnostic/device canister connection

    SciTech Connect

    Boyce, L.

    1981-09-01

    Underground nuclear explosive tests utilize a nuclear device canister suspended from a canister containing diagnostic equipment. A standard design for these canisters and their connection is being developed by the Nuclear Test Engineering Divisions, Test Systems Section of Lawrence Livermore National Laboratory. Test and analysis of a new bolt configuration for a portion of this bolted canister connection have been carried out and results are presented and compared for channel loads of 100,000 and 200,000 lb. When results for this connection design are compared with an earlier one, significant reductions are found in bolt loads, end plate separations, and certain stresses and moments.

  18. Development of an FPGA-based multipoint laser pyroshock measurement system for explosive bolts.

    PubMed

    Abbas, Syed Haider; Jang, Jae-Kyeong; Lee, Jung-Ryul; Kim, Zaeill

    2016-07-01

    Pyroshock can cause failure to the objective of an aerospace structure by damaging its sensitive electronic equipment, which is responsible for performing decisive operations. A pyroshock is the high intensity shock wave that is generated when a pyrotechnic device is explosively triggered to separate, release, or activate structural subsystems of an aerospace architecture. Pyroshock measurement plays an important role in experimental simulations to understand the characteristics of pyroshock on the host structure. This paper presents a technology to measure a pyroshock wave at multiple points using laser Doppler vibrometers (LDVs). These LDVs detect the pyroshock wave generated due to an explosive-based pyrotechnical event. Field programmable gate array (FPGA) based data acquisition is used in the study to acquire pyroshock signals simultaneously from multiple channels. This paper describes the complete system design for multipoint pyroshock measurement. The firmware architecture for the implementation of multichannel data acquisition on an FPGA-based development board is also discussed. An experiment using explosive bolts was configured to test the reliability of the system. Pyroshock was generated using explosive excitation on a 22-mm-thick steel plate. Three LDVs were deployed to capture the pyroshock wave at different points. The pyroshocks captured were displayed as acceleration plots. The results showed that our system effectively captured the pyroshock wave with a peak-to-peak magnitude of 303 741 g. The contribution of this paper is a specialized architecture of firmware design programmed in FPGA for data acquisition of large amount of multichannel pyroshock data. The advantages of the developed system are the near-field, multipoint, non-contact, and remote measurement of a pyroshock wave, which is dangerous and expensive to produce in aerospace pyrotechnic tests.

  19. Development of an FPGA-based multipoint laser pyroshock measurement system for explosive bolts

    NASA Astrophysics Data System (ADS)

    Abbas, Syed Haider; Jang, Jae-Kyeong; Lee, Jung-Ryul; Kim, Zaeill

    2016-07-01

    Pyroshock can cause failure to the objective of an aerospace structure by damaging its sensitive electronic equipment, which is responsible for performing decisive operations. A pyroshock is the high intensity shock wave that is generated when a pyrotechnic device is explosively triggered to separate, release, or activate structural subsystems of an aerospace architecture. Pyroshock measurement plays an important role in experimental simulations to understand the characteristics of pyroshock on the host structure. This paper presents a technology to measure a pyroshock wave at multiple points using laser Doppler vibrometers (LDVs). These LDVs detect the pyroshock wave generated due to an explosive-based pyrotechnical event. Field programmable gate array (FPGA) based data acquisition is used in the study to acquire pyroshock signals simultaneously from multiple channels. This paper describes the complete system design for multipoint pyroshock measurement. The firmware architecture for the implementation of multichannel data acquisition on an FPGA-based development board is also discussed. An experiment using explosive bolts was configured to test the reliability of the system. Pyroshock was generated using explosive excitation on a 22-mm-thick steel plate. Three LDVs were deployed to capture the pyroshock wave at different points. The pyroshocks captured were displayed as acceleration plots. The results showed that our system effectively captured the pyroshock wave with a peak-to-peak magnitude of 303 741 g. The contribution of this paper is a specialized architecture of firmware design programmed in FPGA for data acquisition of large amount of multichannel pyroshock data. The advantages of the developed system are the near-field, multipoint, non-contact, and remote measurement of a pyroshock wave, which is dangerous and expensive to produce in aerospace pyrotechnic tests.

  20. Development of an FPGA-based multipoint laser pyroshock measurement system for explosive bolts.

    PubMed

    Abbas, Syed Haider; Jang, Jae-Kyeong; Lee, Jung-Ryul; Kim, Zaeill

    2016-07-01

    Pyroshock can cause failure to the objective of an aerospace structure by damaging its sensitive electronic equipment, which is responsible for performing decisive operations. A pyroshock is the high intensity shock wave that is generated when a pyrotechnic device is explosively triggered to separate, release, or activate structural subsystems of an aerospace architecture. Pyroshock measurement plays an important role in experimental simulations to understand the characteristics of pyroshock on the host structure. This paper presents a technology to measure a pyroshock wave at multiple points using laser Doppler vibrometers (LDVs). These LDVs detect the pyroshock wave generated due to an explosive-based pyrotechnical event. Field programmable gate array (FPGA) based data acquisition is used in the study to acquire pyroshock signals simultaneously from multiple channels. This paper describes the complete system design for multipoint pyroshock measurement. The firmware architecture for the implementation of multichannel data acquisition on an FPGA-based development board is also discussed. An experiment using explosive bolts was configured to test the reliability of the system. Pyroshock was generated using explosive excitation on a 22-mm-thick steel plate. Three LDVs were deployed to capture the pyroshock wave at different points. The pyroshocks captured were displayed as acceleration plots. The results showed that our system effectively captured the pyroshock wave with a peak-to-peak magnitude of 303 741 g. The contribution of this paper is a specialized architecture of firmware design programmed in FPGA for data acquisition of large amount of multichannel pyroshock data. The advantages of the developed system are the near-field, multipoint, non-contact, and remote measurement of a pyroshock wave, which is dangerous and expensive to produce in aerospace pyrotechnic tests. PMID:27475551

  1. Influence of fretting on flexural fatigue of 304 stainless steel and mild steel

    NASA Technical Reports Server (NTRS)

    Bill, R. C.; Rohn, D. A.

    1978-01-01

    Fretting fatigue experiments conducted on 304 stainless steel using a flexural fatigue test arrangement with bolted on fretting pads demonstrated that fatigue life is reduced by at least a factor of 10 in the 265 to 334 MPa (38,500 - to 48,500 psi) nominal flexural fatigue stress range. In addition, experiments in which the fretting pads were removed after selected numbers of cycles, followed by continued flexural fatigue without fretting show that continued fretting beyond 50,000 cycles does not significantly further reduce fatigue life of 304 stainless steel at 317 MPa (46,000 psi). Microscopic examination of the fretted contact areas revealed fracture initiation sites as well as numerous cracks that did not propagate to failure. Flexural fretting fatigue experiments performed on mild steel showed an insensitivity of fatigue life to the incidence of fretting under flexural stress conditions of from 162 to 217 MPa (23,500 to 31,500 psi).

  2. A Reduced Order Model of Force Displacement Curves for the Failure of Mechanical Bolts in Tension.

    SciTech Connect

    Moore, Keegan J.; Brake, Matthew Robert

    2015-12-01

    Assembled mechanical systems often contain a large number of bolted connections. These bolted connections (joints) are integral aspects of the load path for structural dynamics, and, consequently, are paramount for calculating a structure's stiffness and energy dissipation prop- erties. However, analysts have not found the optimal method to model appropriately these bolted joints. The complexity of the screw geometry causes issues when generating a mesh of the model. This report will explore different approaches to model a screw-substrate connec- tion. Model parameters such as mesh continuity, node alignment, wedge angles, and thread to body element size ratios are examined. The results of this study will give analysts a better understanding of the influences of these parameters and will aide in finding the optimal method to model bolted connections.

  3. A physical match of a metallic chip found on a bolt cutters' blade.

    PubMed

    Finkelstein, Nir; Volkov, Nikolai; Novoselsky, Yehuda; Tsach, Tsadok

    2015-05-01

    Bolt cutters are known as devices which are used for cutting hard objects and rigid materials such as padlocks and bars. They are commonly used in instances of forced entries. In this case study, a bolt cutter was found in the car of two suspects in a grocery burglary. This study indicates how the presence of a small metallic chip found on a suspected bolt cutter can prove that the tool was used in the crime scene. During the initial examination, a metallic chip from the cut shackle padlock was found stuck to one of the bolt cutters' blades. By comparing the metallic chip's microscopic edge and the breaking (fracture) line of the padlock's shackle, a full physical match was noticed. We wish to report here how residue, even the smallest, can be used to link burglary tools to a crime scene with a high level of certainty. PMID:25716459

  4. Experimental analysis of thread movement in bolted connections due to vibrations

    NASA Technical Reports Server (NTRS)

    Ramey, G. ED; Jenkins, Robert C.

    1994-01-01

    The objective of this study was to identify the main design parameters contributing to loosening of bolts due to vibration and to identify their relative importance and degree of contribution to bolt loosening. Vibration testing was conducted on a shaketable with a controlled-random input in the dynamic testing laboratory of the Structural Test Division of MSFC. Test specimens which contained one test bolt were vibrated for a fixed amount of time and percentage of pre-load loss was measured. Each specimen tested implemented some combination of eleven design parameters as dictated by the design of experiment methodology employed. The eleven design parameters were: bolt size (diameter), lubrication on bolt, hole tolerance, initial pre-load, nut locking device, grip length, thread pitch, lubrication between mating materials, class of fit, joint configuration and mass of configuration. These parameters were chosen for this experiment because they are believed to be the design parameters having the greatest impact on bolt loosening. Two values of each design parameter were used and each combination of parameters tested was subjected to two different directions of vibration and two different g-levels of vibration. One replication was made for each test to gain some indication of experimental error and repeatability and to give some degree of statistical credibility to the data, resulting in a total of 96 tests being performed. The results of the investigation indicated that nut locking devices, joint configuration, fastener size, and mass of configuration were significant in bolt loosening due to vibration. The results of this test can be utilized to further research the complex problem of bolt loosening due to vibration.

  5. Experimental analysis of thread movement in bolted connections due to vibrations

    NASA Technical Reports Server (NTRS)

    Ramsey, G. ED; Jenkins, Robert C.

    1995-01-01

    This is the final report of research project NAS8-39131 #33 sponsored by NASA's George C. Marshall Space Flight Center (MSFC) and carried out by the Civil Engineering Department of Auburn University (Auburn, Alabama) and personnel of MSFC. The objective of this study was to identify the main design parameters contributing to the loosening of bolts due to vibration and to identify their relative importance and degree of contribution to bolt loosening. Vibration testing was conducted on a shaketable with a controlled-random input in the dynamic testing laboratory of the Structural Test Division of MSFC. Test specimens which contained one test bolt were vibrated for a fixed amount of time and a percentage of pre-load loss was measured. Each specimen tested implemented some combination of eleven design parameters as dictated by the design of experiment methodology employed. The eleven design parameters were: bolt size (diameter), lubrication on bolt, hole tolerance, initial pre-load, nut locking device, grip length, thread pitch, lubrication between mating materials, class of fit, joint configuration, and mass of configuration. These parameters were chosen for this experiment because they are believed to be the design parameters having the greatest impact on bolt loosening. Two values of each design parameter were used and each combination of parameters tested was subjected to two different directions of vibration and two different g-levels of vibration. One replication was made for each test to gain some indication of experimental error and repeatability and to give some degree of statistical credibility to the data, resulting in a total of 96 tests being performed. The results of the investigation indicated that nut locking devices, joint configuration, fastener size, and mass of configuration were significant in bolt loosening due to vibration. The results of this test can be utilized to further research the complex problem of bolt loosening due to vibration.

  6. Evaluation of a pneumatically operated captive bolt for stunning/killing broiler chickens.

    PubMed

    Raj, A B; O'Callaghan, M

    2001-07-01

    1. Two separate experiments were carried out in this study. In experiment 1, the effectiveness of stunning broilers, as determined from physical responses, with a 6 mm diameter bolt and an air line pressure of 827 kPa, when fired at 90 degrees (perpendicular to the skull) 110 degrees, 120 degrees and 130 degrees (leaning towards beak) was evaluated. 2. In experiment 2, the effects of perpendicular shooting with two bolt diameters (3 and 6 mm) and two air line pressures (620 and 827 kPa) on spontaneous behaviour, electroencephalogram (EEG) and visually evoked potentials (VEPs) were evaluated in broilers. 3. Only the perpendicular shooting was effective in stunning/killing broilers (n= 10) as indicated by the immediate cessation of breathing and loss of neck muscle tension and eye reflexes. Deviations from the perpendicular shooting failed to stun 5 out of 9 broilers. The perpendicular vs non-perpendicular effect was significant. 4. Shooting broilers with a 3 mm bolt at air line pressures of 620 kPa (n=2) or 827 kPa (n=2) failed stun as indicated by the unaltered physical reflexes, EEG and VEPs. Shooting of two broilers with a 6 mm bolt at 620 kPa resulted in effective stunning and a very rapid recovery of consciousness in one bird and death in the other. 5. Captive bolt stunning of broilers with a 6 mm bolt and air line pressure of 827 kPa resulted in an immediate stun leading to death in all 6 broilers tested. In these broilers, a profound EEG suppression and abolition of VEPs occurred immediately after shooting. 6. It is suggested that the appropriate variables for captive bolt stunning of broilers are a minimum of 6 mm bolt diameter driven at an air line pressure of 827 kPa and a penetration depth of 10 mm. PMID:11469546

  7. Evaluation of mounting bolt loads for Space Shuttle Get Away Special (GAS) adapter beam

    NASA Technical Reports Server (NTRS)

    Talapatra, D. C.

    1983-01-01

    During the prototype vibration tests of the GAS adapter beam, significant impacting of the beam at its support points was observed. The cause of the impacting was traced to gaps under the mounting bolt heads. Because of the nonlinear nature of the response, it was difficult to evaluate the effects which Shuttle launch dynamics might have on the mounting bolt loads. A series of tests were conducted on an electrodynamic exciter in which the transient acceleration time histories, which had been measured during the Space Transportation System-1 (STS-1; Space Shuttle mission 1) launch, were simulated. The actual flight data had to be filtered and compensated so that it could be reproduced on the shaker without exceeding displacement and velocity limitations. Mounting bolt loads were measured directly by strain gages applied to the bolts. Various gap thicknesses and bolt torques were investigated. Although increased gap thickness resulted in greater accelerations due to impacting, the bolt loads were not significantly affected. This is attributed to the fact that impacting excited mostly higher frequency modes which do not have significant modal mass.

  8. Experimental studies on the effects of bolt parameters on the bearing characteristics of reinforced rock.

    PubMed

    Cheng, Liang; Zhang, Yidong; Ji, Ming; Zhang, Kai; Zhang, Minglei

    2016-01-01

    Roadways supported by bolts contain support structures that are built into the rock surrounding the roadway, referred to as reinforced rocks in this paper. Using physical model simulation, the paper investigates the bearing characteristics of the reinforced rock under different bolt parameters with incrementally increased load. The experimental results show that the stress at the measurement point inside the structure varies with the kinetic pressure. The stress increases slowly as the load is initially applied, displays accelerated growth in the middle of the loading application, and decreases or remains constant in the later stage of the loading application. The change in displacement of the surrounding rock exhibits the following characteristics: a slow increase when the load is first applied, accelerated growth in the middle stage, and violent growth in the later stage. There is a good correlation between the change in the measured stress and the change in the surrounding rock displacement. Increasing the density of the bolt support and the length and diameter of the bolt improves the load-bearing performance of the reinforced rock, including its strength, internal peak stress, and residual stress. Bolting improves the internal structure of the surrounding rocks, and the deterioration of the surrounding rock decreases with the distance between the bolt supports.

  9. Experimental studies on the effects of bolt parameters on the bearing characteristics of reinforced rock.

    PubMed

    Cheng, Liang; Zhang, Yidong; Ji, Ming; Zhang, Kai; Zhang, Minglei

    2016-01-01

    Roadways supported by bolts contain support structures that are built into the rock surrounding the roadway, referred to as reinforced rocks in this paper. Using physical model simulation, the paper investigates the bearing characteristics of the reinforced rock under different bolt parameters with incrementally increased load. The experimental results show that the stress at the measurement point inside the structure varies with the kinetic pressure. The stress increases slowly as the load is initially applied, displays accelerated growth in the middle of the loading application, and decreases or remains constant in the later stage of the loading application. The change in displacement of the surrounding rock exhibits the following characteristics: a slow increase when the load is first applied, accelerated growth in the middle stage, and violent growth in the later stage. There is a good correlation between the change in the measured stress and the change in the surrounding rock displacement. Increasing the density of the bolt support and the length and diameter of the bolt improves the load-bearing performance of the reinforced rock, including its strength, internal peak stress, and residual stress. Bolting improves the internal structure of the surrounding rocks, and the deterioration of the surrounding rock decreases with the distance between the bolt supports. PMID:27386315

  10. The effect of cultivar, sowing date and transplant location in field on bolting of Welsh onion (Allium fistulosum L.)

    PubMed Central

    2013-01-01

    Background Bolting reduces the quality and commercial yield of Welsh onion (Allium fistulosum L.) in production. However, seed production is directly dependent on flower induction and bolting. The Welsh onion belongs to the green plant vernalisation type, specific seedling characteristics and sufficient accumulated time at low temperature are indispensible for the completion of its vernalisation process. Only if these conditions for vernalisation are fulfilled, the plants will bolt in the following year. The present investigation evaluated the effects of cultivar, sowing date and transplant location in field on the bolting of Welsh onion at the Horticultural Farm of the College of Horticulture, Northwest A&F University, Yangling, Shannxi Province, China in two succeeding production years: 2010–2011 and 2011–2012. A strip split plot layout within a randomised complete block design with three replications was used. Results The results revealed that all three factors (cultivar, sowing date and transplant location) and their interaction had significant effects on the initiation and final rate of bolting observed by 30 April. The earliest bolting date (14 February, 2011 and 15 February, 2012) and the highest bolting rate (100% in 2011 and 62% in 2012) occurred when the JinGuan cultivar was sown on 20 August and transplanted in a plastic tunnel, whereas the latest date and lowest rate (no bolting observed until 30 April) of bolting occurred when the XiaHei cultivar was sown on 29 September and transplanted in an open field. Conclusions These results suggest that we can control bolting in Welsh onion production by choosing an appropriate cultivar, sowing date and transplant location. Choosing a late bolting cultivar, such as cultivar XiaHei, sowing around October, and transplanting in the open field can significantly delay bolting, while a sowing date in late August should be selected for seed production, and the seedlings should be transplanted in a plastic tunnel to

  11. Forces in bolted joints: analysis methods and test results utilized for nuclear core applications (LWBR Development Program)

    SciTech Connect

    Crescimanno, P.J.; Keller, K.L.

    1981-03-01

    Analytical methods and test data employed in the core design of bolted joints for the LWBR core are presented. The effects of external working loads, thermal expansion, and material stress relaxation are considered in the formulation developed to analyze joint performance. Extensions of these methods are also provided for bolted joints having both axial and bending flexibilities, and for the effect of plastic deformation on internal forces developed in a bolted joint. Design applications are illustrated by examples.

  12. Nuts and Bolts of the Ion Band State Theory

    NASA Astrophysics Data System (ADS)

    Chubb, Scott R.

    2005-12-01

    The nuts and bolts of our ion band state theory of low energy nuclear reactions (LENR's) in palladium-deuteride (PdD) and palladium-hydride (PdH) are the electrons that hold together or tear apart the bonds (or lack of bonds) between deuterons (d's) or protons (p's) and the host material. In PdDx and PdHx, this bonding is strongly correlated with loading. In ambient loading conditions (x ≲ 0.6), bonding inhibits ion band state occupation. As x → 1, slight increases and decreases in loading can induce "vibrations" (which have conventionally been thought to occur from phonons) that can induce potential losses or increases of p/d. Naive assumptions about phonons fail to include these losses and increases. These effects can occur because neither H or D has core electrons and because in either PdD or PdH, the electrons near the Fermi energy have negligible overlap with the nucleus of either D or H. In the past, implicitly, we have used these facts to justify our ion band state theory. Here, we present a more formal justification, based on the relationship between H(D) ion band states (IBS's) and H(D) phonons that includes a microscopic picture that explains why occupation of IBS's can occur in PdD and PdH and how this can lead to nuclear reactions.

  13. Transcriptomic Analysis Identifies Differentially Expressed Genes (DEGs) Associated with Bolting and Flowering in Radish (Raphanus sativus L.).

    PubMed

    Nie, Shanshan; Li, Chao; Wang, Yan; Xu, Liang; Muleke, Everlyne M; Tang, Mingjia; Sun, Xiaochuan; Liu, Liwang

    2016-01-01

    The transition of vegetative growth to bolting and flowering is an important process in the life cycle of plants, which is determined by numerous genes forming an intricate network of bolting and flowering. However, no comprehensive identification and profiling of bolting and flowering-related genes have been carried out in radish. In this study, RNA-Seq technology was applied to analyze the differential gene expressions during the transition from vegetative stage to reproductive stage in radish. A total of 5922 differentially expressed genes (DEGs) including 779 up-regulated and 5143 down-regulated genes were isolated. Functional enrichment analysis suggested that some DEGs were involved in hormone signaling pathways and the transcriptional regulation of bolting and flowering. KEGG-based analysis identified 37 DEGs being involved in phytohormone signaling pathways. Moreover, 95 DEGs related to bolting and flowering were identified and integrated into various flowering pathways. Several critical genes including FT, CO, SOC1, FLC, and LFY were characterized and profiled by RT-qPCR analysis. Correlation analysis indicated that 24 miRNA-DEG pairs were involved in radish bolting and flowering. Finally, a miRNA-DEG-based schematic model of bolting and flowering regulatory network was proposed in radish. These outcomes provided significant insights into genetic control of radish bolting and flowering, and would facilitate unraveling molecular regulatory mechanism underlying bolting and flowering in root vegetable crops.

  14. Transcriptomic Analysis Identifies Differentially Expressed Genes (DEGs) Associated with Bolting and Flowering in Radish (Raphanus sativus L.)

    PubMed Central

    Nie, Shanshan; Li, Chao; Wang, Yan; Xu, Liang; Muleke, Everlyne M.; Tang, Mingjia; Sun, Xiaochuan; Liu, Liwang

    2016-01-01

    The transition of vegetative growth to bolting and flowering is an important process in the life cycle of plants, which is determined by numerous genes forming an intricate network of bolting and flowering. However, no comprehensive identification and profiling of bolting and flowering-related genes have been carried out in radish. In this study, RNA-Seq technology was applied to analyze the differential gene expressions during the transition from vegetative stage to reproductive stage in radish. A total of 5922 differentially expressed genes (DEGs) including 779 up-regulated and 5143 down-regulated genes were isolated. Functional enrichment analysis suggested that some DEGs were involved in hormone signaling pathways and the transcriptional regulation of bolting and flowering. KEGG-based analysis identified 37 DEGs being involved in phytohormone signaling pathways. Moreover, 95 DEGs related to bolting and flowering were identified and integrated into various flowering pathways. Several critical genes including FT, CO, SOC1, FLC, and LFY were characterized and profiled by RT-qPCR analysis. Correlation analysis indicated that 24 miRNA-DEG pairs were involved in radish bolting and flowering. Finally, a miRNA-DEG-based schematic model of bolting and flowering regulatory network was proposed in radish. These outcomes provided significant insights into genetic control of radish bolting and flowering, and would facilitate unraveling molecular regulatory mechanism underlying bolting and flowering in root vegetable crops. PMID:27252709

  15. Strengths of composite-to-metal double-lap bolted joints

    NASA Astrophysics Data System (ADS)

    Sun, Hsien-Tang

    1998-12-01

    A three-dimensional analysis was proposed to study the through-the-thickness clamping effect on the bearing failure of double-lap bolted laminated composite joints. Experiments were first performed to characterize the material response due to bearing failure in composite bolted joints with and without lateral clamp-up supports. Composite plates made of T800H/3900-2 graphite/epoxy were selected in the tests, and various washer sizes and clamping forces were used in the study. The clamping force in the bolt was found to vary with the applied load, and may increase significantly due to a sudden through-the-thickness expansion of the laminate under the washers where bearing failure occurred. Experiments showed that the joint strength and response can be significantly affected by the bolt clamp-up, and the bolt bearing failure is a 3-D phenomenon. In order to facilitate the use of the proposed model with the ABAQUS code, an interface module 3DBOLT was developed. In order to reinforce the incompressibility condition in calculations for bearing-damaged material predicted by the model, the condition was imposed through a penalty method in the frame work of finite element analyses. The module provides a user-friendly input deck, generates automatically a joint mesh, and produces outputs and graphics for displaying the stresses, strains, and deformations of the joints and for simulating the failure progression in joints during loading. Extensive comparisons were made between the test data and model predictions. Overall, the model predicts both the failure load and response of bolted composite joints very well for various clamping forces and washer sizes. The model also predicted very well for joints failed in net-tension and shear-out modes. The predicted bolt clamp-up load as a function of the applied load agreed also very well with the data, which validates that the proposed incompressibility assumption for bearing-damaged material. Based on the model, a parametric study

  16. International Space Station Powered Bolt Nut Anomaly and Failure Analysis Summary

    NASA Technical Reports Server (NTRS)

    Sievers, Daniel E.; Warden, Harry K.

    2010-01-01

    A key mechanism used in the on-orbit assembly of the International Space Station (ISS) pressurized elements is the Common Berthing Mechanism. The mechanism that effects the structural connection of the Common Berthing Mechanism halves is the Powered Bolt Assembly. There are sixteen Powered Bolt Assemblies per Common Berthing Mechanism. The Common Berthing Mechanism has a bolt which engages a self aligning Powered Bolt Nut (PBN) on the mating interface (Figure 1). The Powered Bolt Assemblies are preloaded to approximately 84.5 kN (19000 lb) prior to pressurization of the CBM. The PBNs mentioned below, manufactured in 2009, will be used on ISS future missions. An on orbit functional failure of this hardware would be unacceptable and in some instances catastrophic due to the failure of modules to mate and seal the atmosphere, risking loss of crew and ISS functions. The manufacturing processes that create the PBNs need to be strictly controlled. Functional (torque vs. tension) acceptance test failures will be the result of processes not being strictly followed. Without the proper knowledge of thread tolerances, fabrication techniques, and dry film lubricant application processes, PBNs will be, and have been manufactured improperly. The knowledge gained from acceptance test failures and the resolution of those failures, thread fabrication techniques and thread dry film lubrication processes can be applied to many aerospace mechanisms to enhance their performance. Test data and manufactured PBN thread geometry will be discussed for both failed and successfully accepted PBNs.

  17. International Space Station Powered Bolt Nut Anomaly and Failure Analysis Summary

    NASA Technical Reports Server (NTRS)

    Sievers, Daniel E.; Warden, Harry K.

    2010-01-01

    A key mechanism used in the on-orbit assembly of the International Space Station (ISS) pressurized elements is the Common Berthing Mechanism (CBM). The mechanism that effects the structural connection of the CBM halves is the Powered Bolt Assembly. There are sixteen Powered Bolt Assemblies per CBM. The CBM has a bolt which engages a self aligning Powered Bolt Nut (PBN) on the mating interface; see Figure 1. The Powered Bolt Assemblies are preloaded to approximately 19 kilo pounds (KIPs) prior to pressurization of the CBM. The PBNs mentioned below, manufactured in 2009, will be used on ISS future missions. An on orbit functional failure of this hardware would be unacceptable and in some instances catastrophic due to the failure of modules to mate and seal the atmosphere, risking loss of crew and ISS functions. The manufacturing processes which create the PBNs need to be strictly controlled. Functional (torque vs. tension) acceptance test failures will be the result of processes not being strictly followed. Without the proper knowledge of thread tolerances, fabrication techniques, and dry film lubricant application processes, PBNs will be, and have been manufactured improperly. The knowledge gained from acceptance test failures and the resolution of those failures, thread fabrication techniques and thread dry film lubrication processes can be applied to many aerospace mechanisms to enhance their performance. Test data and manufactured PBN thread geometry will be discussed for both failed and successfully accepted PBNs.

  18. Submillimeter bolt location in car bodywork for production line quality inspection

    NASA Astrophysics Data System (ADS)

    Altamirano-Robles, Leopoldo; Arias-Estrada, Miguel; Alviso-Quibrera, Samuel; Lopez-Lopez, Aurelio

    2000-03-01

    In the automotive industry, a vehicle begins with the construction of the vehicle floor. Later on, several robots weld a series of bolts to this floor which are used to fix other parts. Due to several problems, like welding tools wearing, robot miscalibration or momentary low power supply, among others, some bolts are incorrectly positioned or are not present at all, bringing problems and delays in the next work cells. Therefore, it is of importance to verify the quality of welded parts before the following assembly steps. A computer vision system is proposed in order to locate autonomously the presence and quality of the bolts. The system should carry on the inspection in real time at the car assembly line under the following conditions: without touching the bodywork, with a precision in the submillimeter range and in few seconds. In this paper we present a basic computer vision system for bolt location in the submillimeter range. We analyze three arrangements of the system components (camera and illumination sources) that produce different results in the localization. Results are presented and compared for the three approaches obtained under laboratory conditions. The algorithms were tested in the assembling line. Variations up to one millimeter in the welded position of the bolts were observed.

  19. Nonrotating, self-centering anchor assembly for anchoring a bolt in a borehole

    SciTech Connect

    Bevan, John E.; King, Grant W.

    1997-12-01

    An expandable anchor assembly is provided for anchoring the threaded end portion of an elongated roof bolt in a borehole. The anchoring assembly includes a hollow outer sleeve in the form of a plurality of symmetrically arranged, longitudinal segmented wall portions with exterior gripping teeth and an inner expander sleeve in the form of a corresponding plurality of longitudinal wall portions symmetrically arranged about a central axis to define an inner threaded cylindrical section. The inner sleeve is captured within and moveable axially relative to the outer sleeve. As the threaded end portion of the elongated bolt is inserted into the inner threaded cylindrical section of the inner sleeve from the trailing end to the leading end thereof, the inner sleeve expands over and clamps around the threaded end portion of the elongated bolt. Thereafter, partial withdrawal of the elongated bolt from the borehole causes the inner sleeve to axially move relative to the outer sleeve from the leading end toward the trailing end of the outer sleeve in a wedging action to cause the outer sleeve to radially expand and force engagement of the gripping teeth against the sidewall of the borehole to thereby secure the expandable anchor assembly and therewith the threaded end portion of the elongated bolt within the borehole.

  20. Proteomic and gene expression analyses during bolting-related leaf color change in Brassica rapa.

    PubMed

    Zhang, Y W; Guo, M H; Tang, X B; Jin, D; Fang, Z Y

    2016-01-01

    Bolting and flowering are key processes during the growth and development of Chinese cabbage (Brassica rapa L. ssp pekinensis). Understanding the molecular mechanisms underlying bolting and flowering is of significance for improving production of the vegetable. A leaf-color change from bright green to gray-green has been observed following differentiation of the flowering stem and before bolting in the vegetable, and is considered to be a signal for bolting. Proteomics in meristem tissues of an inbred line (C30) were analyzed by two-dimensional electrophoresis during the transition period. We found that some proteins were specifically expressed while others were differentially expressed. Among these, 17 proteins were specifically expressed before the color change, 18 were specifically expressed after the color change, 21 were downregulated during the color change, and 29 were upregulated. Mass spectrometric analysis (MALDI-TOF-TOF/MS) was used to analyze 17 protein spots, and four proteins (subunit E1 of vacuolar-type H+ transporter ATPase, the large subunit of Rubicon, S-adenosylmethionine synthetase, and tubulin α-2) were identified. qPCR analysis was conducted to quantify the expression of genes encoding these proteins during the transitional period. The expression of BrVHA-E1, BrSAMS, BrrbcL, and BrTUA6 was significantly different before and after the leaf-color change, suggesting that these genes might be involved in regulating flower differentiation and bolting.

  1. Load apparatus and method for bolt-loaded compact tension test specimen

    DOEpatents

    Buescher, Jr., Brent J.; Lloyd, W. Randolph; Ward, Michael B.; Epstein, Jonathan S.

    1997-01-01

    A bolt-loaded compact tension test specimen load apparatus includes: a) a body having first and second opposing longitudinal ends, the first end comprising an externally threaded portion sized to be threadedly received within the test specimen threaded opening; b) a longitudinal loading rod having first and second opposing longitudinal ends, the loading rod being slidably received in a longitudinal direction within the body internally through the externally threaded portion and slidably extending longitudinally outward of the body first longitudinal end; c) a force sensitive transducer slidably received within the body and positioned to engage relative to the loading rod second longitudinal end; and d) a loading bolt threadedly received relative to the body, the loading bolt having a bearing end surface and being positioned to bear against the transducer to forcibly sandwich the transducer between the loading bolt and loading rod. Also disclosed is a method of in situ determining applied force during crack propagation in a bolt-loaded compact tension test specimen.

  2. Load apparatus and method for bolt-loaded compact tension test specimen

    DOEpatents

    Buescher, B.J. Jr.; Lloyd, W.R.; Ward, M.B.; Epstein, J.S.

    1997-02-04

    A bolt-loaded compact tension test specimen load apparatus includes: (a) a body having first and second opposing longitudinal ends, the first end comprising an externally threaded portion sized to be threadedly received within the test specimen threaded opening; (b) a longitudinal loading rod having first and second opposing longitudinal ends, the loading rod being slidably received in a longitudinal direction within the body internally through the externally threaded portion and slidably extending longitudinally outward of the body first longitudinal end; (c) a force sensitive transducer slidably received within the body and positioned to engage relative to the loading rod second longitudinal end; and (d) a loading bolt threadedly received relative to the body, the loading bolt having a bearing end surface and being positioned to bear against the transducer to forcibly sandwich the transducer between the loading bolt and loading rod. Also disclosed is a method of in situ determining applied force during crack propagation in a bolt-loaded compact tension test specimen. 6 figs.

  3. PIXE Analysis of Metal Hull Bolts From HMB DeBraak

    SciTech Connect

    Correll, Francis D.; Cole, Lord K.; Slater, Charles J.; Vanhoy, Jeffrey R.; Fithian, Charles H.

    2009-03-10

    HMB DeBraak was a 16-gun British brig-sloop that sank in a squall on May 25, 1798 off Cape Henlopen, Delaware. Silt covered the wooden hull shortly after it sank, preserving it until DeBraak was raised in 1986. The items recovered from the ship include metal bolts that held the hull together. We used PIXE to measure the compositions of 45 of the bolts and found that they are nearly pure copper (98.3% on average), with most also containing small amounts of iron (0.87%), nickel (0.039%), arsenic (0.43%), silver (0.089%), lead (0.18%), and bismuth (0.12%). A few contain a little indium, tin, or antimony, but none contain zinc above the quantization level. The compositions are similar to those reported for 18th-century English copper, but different from several copper alloys also used to make hull bolts. We conclude that, when DeBraak was last fitted out in 1795-1797, the Royal Navy was still using bolts similar to William Forbes's mechanically hardened pure copper bolts. Forbes's process represents the successful innovation and application of new technology in Royal Navy ships during the wars of the late 18th century.

  4. Effects of bolt torque and contact resistance on the performance of the polymer electrolyte membrane electrolyzers

    NASA Astrophysics Data System (ADS)

    Selamet, Omer F.; Ergoktas, M. Said

    2015-05-01

    The effect of bolt torque and contact resistance on the performance of Proton Exchange Membrane (PEM) Electrolyzers are investigated by a 50 cm2 cell. The cell is designed and manufactured in house. The performance and contact resistance of the cell with three different gasket materials for demanding bolt torques are measured. The pressure distribution inside the cell is obtained by using pressure sensitive films. The pressure acting on the membrane electrode assembly (MEA) is calculated by analyzing and quantifying intensities of pressure film images. 3D plots of pressure distribution for predefined bolt torque values are obtained to understand the pressure distribution over the active area. The performance of the cell is enhanced when bolt torque is increased. However, beyond a value, relatively weak cell components such as diffusion layers are damaged and performance loss is observed due to the mass transfer limitations. The best efficiency is reached at 15 Nm bolt torque for Polytetrafluoroethylene (PTFE) and Ethylene Propylene Diene Monomer (EPDM) gaskets. For silicon gasket best efficiency is reached at 15 Nm at lower current densities and at 10 Nm at higher current densities. Increasing clamping pressure is found to be developing more contact points between the interfaces and results in decrease in contact resistance inside the cell.

  5. Nonrotating, self-centering anchor assembly for anchoring a bolt in a borehole

    DOEpatents

    Bevan, J.E.; King, G.W.

    1998-12-08

    An expandable anchor assembly is provided for anchoring the threaded end portion of an elongated roof bolt in a borehole. The anchoring assembly includes a hollow outer sleeve in the form of a plurality of symmetrically arranged, longitudinal segmented wall portions with exterior gripping teeth and an inner expander sleeve in the form of a corresponding plurality of longitudinal wall portions symmetrically arranged about a central axis to define an inner threaded cylindrical section. The inner sleeve is captured within and moveable axially relative to the outer sleeve. As the threaded end portion of the elongated bolt is inserted into the inner threaded cylindrical section of the inner sleeve from the trailing end to the leading end thereof, the inner sleeve expands over and clamps around the threaded end portion of the elongated bolt. Thereafter, partial withdrawal of the elongated bolt from the borehole causes the inner sleeve to axially move relative to the outer sleeve from the leading end toward the trailing end of the outer sleeve in a wedging action to cause the outer sleeve to radially expand and force engagement of the gripping teeth against the sidewall of the borehole to thereby secure the expandable anchor assembly and therewith the threaded end portion of the elongated bolt within the borehole. 8 figs.

  6. Nonrotating, self-centering anchor assembly for anchoring a bolt in a borehole

    DOEpatents

    Bevan, John E.; King, Grant W.

    1998-01-01

    An expandable anchor assembly is provided for anchoring the threaded end portion of an elongated roof bolt in a borehole. The anchoring assembly includes a hollow outer sleeve in the form of a plurality of symmetrically arranged, longitudinal segmented wall portions with exterior gripping teeth and an inner expander sleeve in the form of a corresponding plurality of longitudinal wall portions symmetrically arranged about a central axis to define an inner threaded cylindrical section. The inner sleeve is captured within and moveable axially relative to the outer sleeve. As the threaded end portion of the elongated bolt is inserted into the inner threaded cylindrical section of the inner sleeve from the trailing end to the leading end thereof, the inner sleeve expands over and clamps around the threaded end portion of the elongated bolt. Thereafter, partial withdrawal of the elongated bolt from the borehole causes the inner sleeve to axially move relative to the outer sleeve from the leading end toward the trailing end of the outer sleeve in a wedging action to cause the outer sleeve to radially expand and force engagement of the gripping teeth against the sidewall of the borehole to thereby secure the expandable anchor assembly and therewith the threaded end portion of the elongated bolt within the borehole.

  7. Proteomic and gene expression analyses during bolting-related leaf color change in Brassica rapa.

    PubMed

    Zhang, Y W; Guo, M H; Tang, X B; Jin, D; Fang, Z Y

    2016-01-01

    Bolting and flowering are key processes during the growth and development of Chinese cabbage (Brassica rapa L. ssp pekinensis). Understanding the molecular mechanisms underlying bolting and flowering is of significance for improving production of the vegetable. A leaf-color change from bright green to gray-green has been observed following differentiation of the flowering stem and before bolting in the vegetable, and is considered to be a signal for bolting. Proteomics in meristem tissues of an inbred line (C30) were analyzed by two-dimensional electrophoresis during the transition period. We found that some proteins were specifically expressed while others were differentially expressed. Among these, 17 proteins were specifically expressed before the color change, 18 were specifically expressed after the color change, 21 were downregulated during the color change, and 29 were upregulated. Mass spectrometric analysis (MALDI-TOF-TOF/MS) was used to analyze 17 protein spots, and four proteins (subunit E1 of vacuolar-type H+ transporter ATPase, the large subunit of Rubicon, S-adenosylmethionine synthetase, and tubulin α-2) were identified. qPCR analysis was conducted to quantify the expression of genes encoding these proteins during the transitional period. The expression of BrVHA-E1, BrSAMS, BrrbcL, and BrTUA6 was significantly different before and after the leaf-color change, suggesting that these genes might be involved in regulating flower differentiation and bolting. PMID:27525926

  8. Late-bolting transgenic Chinese cabbage obtained by RNA interference technique.

    PubMed

    Xia, Guang-Qing; Zhu, Jun-Yi; He, Qi-Wei; Zhao, Shuang-Yi; Wang, Cui-Hua

    2007-10-01

    LEAFY (LFY) gene plays an important role in determining plant flowering mainly by controlling the timing of phase transition. Constitutive under-expression of LFY in Arabidopsis resulted in the formation of a late-flowering and highly branching phenotype. In this paper, an RNAi approach was used in down-regulated LFY gene expression to delay Chinese cabbage (Brassica rapa L. ssp. pekinensis) bolting and flowering. The results show that transgenic plant has a later transition to the reproductive phase, and the transgenic plants have more branches, more leaves, but a lower height. Results of RQ-RT-PCR analysis show that LFY gene expression was greatly reduced in transgenic plants. These results suggest that inhibiting LFY gene expression by RNA interference can delay bolting in a cold-sensitive long-day (LD) condition. Late flowering of Chinese cabbage can be used as a good genetic resource for the breeding late-bolting Chinese cabbage.

  9. Investigation of Turn-of-Nut Method for Slip-Critical Joints of Aluminum Using A325 Bolts

    SciTech Connect

    Luttrell, C R

    1998-01-01

    Slip-critical bolted joints will be used to join aluminum bridge deck sections by Reynolds Metals Company (RMC). To help ensure that a joint does not slip the proper bolt clamping force to achieve what is known as a friction connection must be determined.

  10. Thermal conductance measurements of bolted copper joints for SuperCDMS

    SciTech Connect

    Schmitt, R.; Tatkowski, Greg; Ruschman, M.; Golwala, S. R.; Kellaris, N.; Daal, M.; Hall, Jeter C.; Hoppe, Eric W.

    2015-09-01

    Joint thermal conductance testing has been undertaken for bolted copper to copper connections from 60 mK to 26 K. This testing was performed to validate an initial design basis for the SuperCDMS experiment, where a dilution refrigerator will be coupled to a cryostat via multiple bolted connections. Copper used during testing was either gold plated or passivated with citric acid to prevent surface oxidation. Results obtained are well fit by a power law regression of joint thermal conductance to temperature and match well with data collected during a literature review.

  11. Response of garlic (Allium sativum L.) bolting and bulbing to temperature and photoperiod treatments.

    PubMed

    Wu, Cuinan; Wang, Mengyi; Cheng, Zhihui; Meng, Huanwen

    2016-01-01

    This research was conducted to evaluate the effect of temperature and photoperiod treatments on the bolting and bulb formation of three local garlic cultivars (cvs) in two consecutive years. Naturally vernalized plants of cvs G107, G025 and G064 were transplanted into growth chambers and subjected to various combinations of temperature [T15/10, 15°C/10°C; T20/15, 20°C/15°C and T25/18, 25°C/18°C (day/night)] and photoperiod (L8, 8 h and L14,14 h) treatments. Plant growth, endogenous phytohormone and methyl jasmonate (MeJA) levels, along with the bolting and yield of garlic were evaluated. The experimental results from two consecutive years indicated that higher temperature (20°C or 25°C) and longer photoperiod (14 h) treatments significantly enhanced the garlic bolting, bulbing and cloving with a shorter growth period and a higher bulb weight. Moreover, the endogenous phytohormone and MeJA levels in the test plants were significantly increased by the higher temperature (25°C for the phytohormone level; 20°C for the MeJA level) and longer photoperiod [14 h, except for abscisic acid (ABA), which had the highest level at 8 h] conditions and were decreased by the lowest test temperature (15°C) and shorter photoperiod (8 h, except for ABA) conditions. This response coincided with that of the bulbing index, bolting rate, growth period and bulb weight. In addition, plants treated under the conditions of 20°C/15°C-14 h and 25°C/18°C-14 h produced the highest phytohormone levels (except for ABA) for cvs G025 and G064, respectively, and showed the best bolting and bulbing behavior. It is reasonable to assume that endogenous phytohormone (especially gibberellic acid) and MeJA levels are highly related to garlic bolting and bulbing, which might lead to the different responses of the three studied cultivars to the combination of temperature and photoperiod treatments. Furthermore, cvs G107 and G025 bolt well and have better bulb formation under 20

  12. Nonlinear Analysis of a Bolted Marine Riser Connector Using NASTRAN Substructuring

    NASA Technical Reports Server (NTRS)

    Fox, G. L.

    1984-01-01

    Results of an investigation of the behavior of a bolted, flange type marine riser connector is reported. The method used to account for the nonlinear effect of connector separation due to bolt preload and axial tension load is described. The automated multilevel substructing capability of COSMIC/NASTRAN was employed at considerable savings in computer run time. Simplified formulas for computer resources, i.e., computer run times for modules SDCOMP, FBS, and MPYAD, as well as disk storage space, are presented. Actual run time data on a VAX-11/780 is compared with the formulas presented.

  13. Thermal conductance measurements of bolted copper joints for SuperCDMS

    DOE PAGES

    Schmitt, R. L.; Tatkowski, G.; Ruschman, M.; Golwala, S.; Kellaris, N.; Daal, M.; Hall, J.; Hoppe, E. W.

    2015-04-28

    Joint thermal conductance testing has been undertaken for bolted copper to copper connections from 60 mK to 26 K. This testing was performed to validate an initial design basis for the SuperCDMS experiment, where a dilution refrigerator will be coupled to a cryostat via multiple bolted connections. Copper used during testing was either gold plated or passivated with citric acid to prevent surface oxidation. Finally, the results we obtained are well fit by a power law regression of joint thermal conductance to temperature and match well with data collected during a literature review.

  14. Response of garlic (Allium sativum L.) bolting and bulbing to temperature and photoperiod treatments

    PubMed Central

    Wu, Cuinan; Wang, Mengyi; Cheng, Zhihui; Meng, Huanwen

    2016-01-01

    ABSTRACT This research was conducted to evaluate the effect of temperature and photoperiod treatments on the bolting and bulb formation of three local garlic cultivars (cvs) in two consecutive years. Naturally vernalized plants of cvs G107, G025 and G064 were transplanted into growth chambers and subjected to various combinations of temperature [T15/10, 15°C/10°C; T20/15, 20°C/15°C and T25/18, 25°C/18°C (day/night)] and photoperiod (L8, 8 h and L14,14 h) treatments. Plant growth, endogenous phytohormone and methyl jasmonate (MeJA) levels, along with the bolting and yield of garlic were evaluated. The experimental results from two consecutive years indicated that higher temperature (20°C or 25°C) and longer photoperiod (14 h) treatments significantly enhanced the garlic bolting, bulbing and cloving with a shorter growth period and a higher bulb weight. Moreover, the endogenous phytohormone and MeJA levels in the test plants were significantly increased by the higher temperature (25°C for the phytohormone level; 20°C for the MeJA level) and longer photoperiod [14 h, except for abscisic acid (ABA), which had the highest level at 8 h] conditions and were decreased by the lowest test temperature (15°C) and shorter photoperiod (8 h, except for ABA) conditions. This response coincided with that of the bulbing index, bolting rate, growth period and bulb weight. In addition, plants treated under the conditions of 20°C/15°C–14 h and 25°C/18°C–14 h produced the highest phytohormone levels (except for ABA) for cvs G025 and G064, respectively, and showed the best bolting and bulbing behavior. It is reasonable to assume that endogenous phytohormone (especially gibberellic acid) and MeJA levels are highly related to garlic bolting and bulbing, which might lead to the different responses of the three studied cultivars to the combination of temperature and photoperiod treatments. Furthermore, cvs G107 and G025 bolt well and have better bulb

  15. Combined In-Plane and Through-the-Thickness Analysis for Failure Prediction of Bolted Composite Joints

    NASA Technical Reports Server (NTRS)

    Kradinov, V.; Madenci, E.; Ambur, D. R.

    2004-01-01

    Although two-dimensional methods provide accurate predictions of contact stresses and bolt load distribution in bolted composite joints with multiple bolts, they fail to capture the effect of thickness on the strength prediction. Typically, the plies close to the interface of laminates are expected to be the most highly loaded, due to bolt deformation, and they are usually the first to fail. This study presents an analysis method to account for the variation of stresses in the thickness direction by augmenting a two-dimensional analysis with a one-dimensional through the thickness analysis. The two-dimensional in-plane solution method based on the combined complex potential and variational formulation satisfies the equilibrium equations exactly, and satisfies the boundary conditions and constraints by minimizing the total potential. Under general loading conditions, this method addresses multiple bolt configurations without requiring symmetry conditions while accounting for the contact phenomenon and the interaction among the bolts explicitly. The through-the-thickness analysis is based on the model utilizing a beam on an elastic foundation. The bolt, represented as a short beam while accounting for bending and shear deformations, rests on springs, where the spring coefficients represent the resistance of the composite laminate to bolt deformation. The combined in-plane and through-the-thickness analysis produces the bolt/hole displacement in the thickness direction, as well as the stress state in each ply. The initial ply failure predicted by applying the average stress criterion is followed by a simple progressive failure. Application of the model is demonstrated by considering single- and double-lap joints of metal plates bolted to composite laminates.

  16. Population structure and association analysis of bolting, plant height, and leaf erectness in spinach

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Spinach (Spinacia oleracea L.) is an important vegetable worldwide with high nutritional and health-promoting compounds. Bolting is an important trait to consider in order to grow spinach in different seasons and regions. Plant height and leaf erectness are important traits for machine-harvesting. B...

  17. A torque, tension and stress corrosion evaluation of high strength A286 bolts

    NASA Technical Reports Server (NTRS)

    Montano, J. W.

    1986-01-01

    The problems associated with overtorque applied to the Booster Separation Motor (BSM) Igniter Adapter high strength 200 KSI (1379 Mpa) A286 CRES bolts and the threaded holes of the 7075-T73 aluminum alloy BSM cases are addressed. The evaluation included torque, tensile, and stress corrosion tests incorporating the A286 CRES bolts and the 7075-T73 aluminum alloy BSM cases. The tensile test data includes ultimate tensile load (UTL), Johnson's 2/3 yield load (J2/3YL), proportional limit load (PLL), and total bolt stretch. Torque tension data includes torque, torque induced load, and positive and negative break-away torque. Stress corrosion test data reflect the overtorque and the resulting torque induced loads sustained by the A286 CRES bolts torqued into a 7075-T73 aluminum alloy forged dome with threaded holes. After 60 days of salt fog exposure, the positive and the negative break-away torques, the subsequent mechanical property tensile test results, and the BSM dome threaded hole axial tensile pullout loads are reported.

  18. Loosening and Sliding Behaviour of Bolt-Nut Fastener under Transverse Loading

    NASA Astrophysics Data System (ADS)

    Hattori, T.; Yamashita, M.; Mizuno, H.; Naruse, T.

    2010-06-01

    The thread joint has been frequently used for the efficient productivity and maintainability as a machine element. However, many troubles such as loosening of bolted joints or fatigue failure of bolt were often experienced. Many attentions must be paid on the improvement of the strength and the reliability of the thread joints [1, 2]. It is generally said that the fastening axial force rapidly decreases by the rotation loosening of nuts if the relative slippage on the interfaces between nuts and fastened body goes beyond a certain critical limit [3]. This critical relative slippage (Scr) that prescribes the upper limit for preventing the loosening behaviour has been estimated according to the theoretically obtained equation considering the bending deformation of bolt and the geometrical constraint condition. In this paper, firstly we present the equation for estimating the Scr based on the fundamental cantilever deformation model. Then we present the investigated results of the deformation behaviour of bolt-nut joint under transverse loading condition considering the reaction moment by nut (Mn). Finaly we can confirmed that these estimated results of critical relative slippage coincided well with the experimental results [4, 5].

  19. 11. Corner of Derrick Showing Bolted Joints and DoublePipe/Wood Beam ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    11. Corner of Derrick Showing Bolted Joints and Double-Pipe/Wood Beam Support For Bull Wheel, Looking Southeast - David Renfrew Oil Rig, East side of Connoquenessing Creek, 0.4 mile North of confluence with Thorn Creek, Renfrew, Butler County, PA

  20. Professor Usain Bolt Welcomes You to the Schoolyard: Physics for Champions

    ERIC Educational Resources Information Center

    Vourlias, Kostas; Seroglou, Fanny

    2016-01-01

    Could Usain Bolt achieve what teachers often fail to do? Could this famous Olympic winner challenge and motivate students to study mechanics and introduce them to the principles of physics in a fun way, outside of the classroom? In order to answer these questions, we "invited" for one semester the world record holder to visit our Greek…

  1. STRUCTURAL ANALYSES OF FUEL CASKS SUBJECTED TO BOLT PRELOAD, INTERNAL PRESSURE AND SEQUENTIAL DYNAMIC IMPACTS

    SciTech Connect

    Wu, T

    2009-06-25

    Large fuel casks subjected to the combined loads of closure bolt tightening, internal pressure and sequential dynamic impacts present challenges when evaluating their performance in the Hypothetical Accident Conditions (HAC) specified in the Code of Federal Regulations Title 10 Part 71 (10CFR71). Testing is often limited by cost, difficulty in preparing test units and the limited availability of facilities which can carry out such tests. In the past, many casks were evaluated without testing by using simplified analytical methods. In addition, there are no realistic analyses of closure bolt stresses for HAC conditions reported in the open literature. This paper presents a numerical technique for analyzing the accumulated damages of a large fuel cask caused by the sequential loads of the closure bolt tightening and the internal pressure as well as the drop and crash dynamic loads. The bolt preload and the internal pressure are treated as quasi-static loads so that the finite element method with explicit numerical integration scheme based on the theory of wave propagation can be applied. The dynamic impacts with short durations such as the 30-foot drop and the 40-inch puncture for the hypothetical accident conditions specified in 10CFR71 are also analyzed by using the finite-element method with explicit numerical integration scheme.

  2. Secondary skull fractures in head wounds inflicted by captive bolt guns: autopsy findings and experimental simulation.

    PubMed

    Perdekamp, Markus Grosse; Kneubuehl, Beat P; Ishikawa, Takaki; Nadjem, Hadi; Kromeier, Jan; Pollak, Stefan; Thierauf, Annette

    2010-11-01

    Apart from one article published by Rabl and Sigrist in 1992 (Rechtsmedizin 2:156-158), there are no further reports on secondary skull fractures in shots from captive bolt guns. Up to now, the pertinent literature places particular emphasis on the absence of indirect lesions away from the impact point, when dealing with the wounding capacity of slaughterer's guns. The recent observation of two suicidal head injuries accompanied by skull fractures far away from the bolt's path gave occasion to experimental studies using simulants (glycerin soap, balls from gelatin) and skull–brain models. As far as ballistic soap was concerned, the dimensions of the bolt's channel were assessed by multi-slice computed tomography before cutting the blocks open. The test shots to gelatin balls and to skull-brain models were documented by means of a high-speed motion camera. As expected, the typical temporary cavity effect of bullets fired from conventional guns could not be observed when captive bolt stunners were discharged. Nevertheless, the visualized transfer of kinetic energy justifies the assumption that the secondary fractures seen in thin parts of the skull were caused by a hydraulic burst effect. PMID:20393855

  3. 77 FR 32698 - Proposed Extension of Existing Information Collection; Safety Standards for Roof Bolts in Metal...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-01

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF LABOR Mine... for Roof Bolts in Metal and Nonmetal Mines and Underground Coal Mines AGENCY: Mine Safety and Health... requirements on respondents can be properly assessed. Currently, the Mine Safety and Health Administration...

  4. The Speed-Power Study of the USES Basic Occupational Literacy Test (BOLT) Analysis and Report.

    ERIC Educational Resources Information Center

    Utah State Dept. of Employment Security, Salt Lake City. Western Test Development Field Center.

    Research and analysis conducted to determine the effects of reducing the administration time for one or more levels of the Basic Occupational Literacy Test (BOLT) are described. The total usable sample consisted of 2,423 subjects. Data were collected from 23 states from 1978 to 1981. Data came from a variety of sources, including schools and…

  5. 12. TOOL ROOM SHOWING LANDIS MACHINE CO. BOL/T THREADER (L), ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    12. TOOL ROOM SHOWING LANDIS MACHINE CO. BOL/T THREADER (L), OSTER MANUFACTURING CO. PIPE MASTER (R), AND OLDMAN KINK, A SHOP-MADE WELDING STRENGTH TESTER (L, BACKGROUND). VIEW NORTHEAST - Oldman Boiler Works, Office/Machine Shop, 32 Illinois Street, Buffalo, Erie County, NY

  6. Secondary skull fractures in head wounds inflicted by captive bolt guns: autopsy findings and experimental simulation.

    PubMed

    Perdekamp, Markus Grosse; Kneubuehl, Beat P; Ishikawa, Takaki; Nadjem, Hadi; Kromeier, Jan; Pollak, Stefan; Thierauf, Annette

    2010-11-01

    Apart from one article published by Rabl and Sigrist in 1992 (Rechtsmedizin 2:156-158), there are no further reports on secondary skull fractures in shots from captive bolt guns. Up to now, the pertinent literature places particular emphasis on the absence of indirect lesions away from the impact point, when dealing with the wounding capacity of slaughterer's guns. The recent observation of two suicidal head injuries accompanied by skull fractures far away from the bolt's path gave occasion to experimental studies using simulants (glycerin soap, balls from gelatin) and skull–brain models. As far as ballistic soap was concerned, the dimensions of the bolt's channel were assessed by multi-slice computed tomography before cutting the blocks open. The test shots to gelatin balls and to skull-brain models were documented by means of a high-speed motion camera. As expected, the typical temporary cavity effect of bullets fired from conventional guns could not be observed when captive bolt stunners were discharged. Nevertheless, the visualized transfer of kinetic energy justifies the assumption that the secondary fractures seen in thin parts of the skull were caused by a hydraulic burst effect.

  7. The Problem with "Nuts and Bolts:" How the Emphasis on "Highly Qualified Professionals" Is Undermining Education

    ERIC Educational Resources Information Center

    Swain, Amy

    2013-01-01

    Schools of education have seen many changes over the last 100 years (Labaree 2004). More recent modifications have included the slow and steady elimination of the social foundations of education in lieu of a more direct attention to teacher skills and basic training. The increased focus on the so-called "nuts and bolts" of teacher education trumps…

  8. Tethered Space Satellite-1 (TSS-1): Wound About a Bolt

    NASA Technical Reports Server (NTRS)

    O'Connor, Brian; Stevens, Jennifer

    2016-01-01

    integration of the hardware into the Shuttle payload bay. An analysis, called Coupled loads analysis, incorporates any updates to the model due to system level tests of all the different payloads, and any changes that were found during integration. Engineering analysis examines the worst case scenarios for the loads the hardware will see. The two times during the mission where the dynamic loads are the worst were 1) the first 10-second portion of Shuttle lift off, and 2) a 2-second time during landing when the landing gears hit the ground. The coupled loads analysis using the final verification loads showed that a single bolt attaching the deployer reel mechanism to the support structure had a "negative margin" - which is an indication that it might fail - during touch down. Hardware certification rules do not allow for hardware to fly with negative margins. A structural failure of one payload could have serious or catastrophic consequences to other payloads, or may significantly damage the Orbiter. The issue had to be resolved before the flight.

  9. An Investigation on Load Bearing Capacities of Cement and Resin Grouted Rock Bolts Installed in Weak Rocks

    NASA Astrophysics Data System (ADS)

    Kalyoncu Erguler, Guzide; Abiddin Erguler, Zeynal

    2015-04-01

    Rock bolts have been considered one of indispensable support method to improve load bearing capacity of many underground engineering projects, and thus, various types of them have been developed until now for different purposes. Although mechanically anchored rock bolts can be successfully installed to prevent structurally controlled instabilities in hard rocks, in comparison with cement and resin grouted rock bolts, these types of anchors are not so effective in weak rocks characterized by relatively low mechanical properties. In order to investigate the applicability and to measure relative performance of cement and resin grouted rock bolts into weak and heavily jointed rock mass, a research program mainly consisting of pull-out tests was performed in a metal mine in Turkey. The rock materials excavated in this underground mining were described as basalt, tuff, ore dominated volcanic rocks and dacite. To achieve more representative results for rock materials found in this mining and openings excavated in varied dimensions, the pull-out tests were conducted on rock bolts used in many different locations where more convergences were measured and deformation dependent instability was expected to cause greater engineering problems. It is well known that the capacity of rock bolts depends on the length, diameter and density of the bolt pattern, and so considering the thickness of plastic zone in the studied openings, the length and diameter of rock bolts were taken as 2.4 m. and 25 mm., respectively. The spacing between rows changed between 70 and 180 cm. In this study, totally twenty five pull-out tests were performed to have a general understanding about axial load bearing capacity and support reaction curves of cement and resin grouted rock bolts. When pull load-displacement curves belongs to cement and resin grouted rock bolts were compared with each other, it was determined that cement grouted rock bolts carry more load ranging between 115.6 kN and 127.5 kN with

  10. Bacterial artificial chromosome-derived molecular markers for early bolting in sugar beet.

    PubMed

    Gaafar, R M; Hohmann, U; Jung, C

    2005-04-01

    Early bolting in sugar beet (Beta vulgaris L.) is controlled by the dominant gene B. From an incomplete physical map around the B gene, 18 bacterial artificial chromosomes (BACs) were selected for marker development. Three BACs were shotgun-sequenced, and 61 open reading frames (ORFs) were identified. Together with 104 BAC ends from 54 BACs, a total number of 55,464 nucleotides were sequenced. Of these, 37 BAC ends and 12 ORFs were selected for marker development. Thirty-one percent of the sequences were found to be single copy and 24%, low copy. From these sequences, 15 markers from ten different BACs were developed. Ten polymorphisms were determined by simple agarose gel electrophoresis of either restricted or non-restricted PCR products. Another five markers were determined by tetra-primer amplification refractory mutation system-PCR. In order to select candidate BACs for cloning the gene, genetic linkage between seven markers and the bolting gene was calculated using 1,617 plants from an F2 population segregating for early bolting. The recombination values ranged between 0.0033 and 0.0201. In addition, a set of 41 wild and cultivated Beta accessions differing in their early bolting character was genotyped with seven markers. A common haplotype encompassing two marker loci and the b allele was found in all sugar beet varieties, indicating complete linkage disequilibrium between these loci. This suggests that the bolting gene is located in close vicinity to these markers, and the corresponding BACs can be used for cloning the gene.

  11. Steel bars and forgings, 0.50Cr 0.55Ni 0.25Mo (0.38 0.43C) (SAE 8740), heat treated, 125,000 psi (862 MPa) tensile strength (reaffirmed, Apr 1994). (SAE standard)

    SciTech Connect

    1988-10-01

    This specification covers an aircraft-quality, low-alloy steel in the form of bars and forgings. Primarily for parts, such as nuts, bolts, and screws, 1.50 inch (38.1 mm) and under in section thickness, requiring a minimum tensile strength of 125,000 (862 MPa). Alloy: 8740 UNS Number: G8740.

  12. Lightweight structural design of a bolted case joint for the Space Shuttle Solid Rocket Motor

    NASA Technical Reports Server (NTRS)

    Dorsey, John T.; Stein, Peter A.; Bush, Harold G.

    1988-01-01

    This paper presents the structural design of a bolted joint with a static face seal which can be used to join Space Shuttle Solid Rocket Motor (SRM) case segments. Results from numerous finite element parametric studies indicate that the bolted joint meets the design requirement of preventing joint opening at the O-ring locations during SRM pressurization. A final design recommended for further development has the following parameters: 180 1-inch-diameter studs, stud center line offset of .5 inches radially inward from the shell wall center line, flange thickness of 0.75 inches, bearing plate thickness of 0.25 inches, studs prestressed to 70 percent of ultimate load, and the intermediate alcove. The design has a mass penalty of 1096 lbm, which is 164 lbm greater than the currently proposed capture tang redesign.

  13. Lightweight structural design of a bolted case joint for the space shuttle solid rocket motor

    NASA Technical Reports Server (NTRS)

    Dorsey, John T.; Stein, Peter A.; Bush, Harold G.

    1988-01-01

    The structural design of a bolted joint with a static face seal which can be used to join Space Shuttle Solid Rocket Motor (SRM) case segments is given. Results from numerous finite element parametric studies indicate that the bolted joint meets the design requirement of preventing joint opening at the O-ring locations during SRM pressurization. A final design recommended for further development has the following parameters: 180 one-in.-diam. studs, stud centerline offset of 0.5 in radially inward from the shell wall center line, flange thickness of 0.75 in, bearing plate thickness of 0.25 in, studs prestressed to 70 percent of ultimate load, and the intermediate alcove. The design has a mass penalty of 1096 lbm, which is 164 lbm greater than the currently proposed capture tang redesign.

  14. Mathematical Model of Load Pass and Prediction of Fatigue Life on Bolt Threads with Reduced Lead

    NASA Astrophysics Data System (ADS)

    Asayama, Yukiteru

    A mathematical model is proposed in order to elucidate the mechanism that the fatigue strength of external threads increases by reducing the lead on a thread system such as a bolt and nut. The model is constructed from the concept that a local strain proportional to the reducing degree of the lead, although the local strain is at first produced in the bolt thread farthest from the bearing surface of the nut, is induced in each thread root with an increase of applied load. The fatigue life predicted from the mathematical model shows good agreement with the experimental fatigue life of cadmium-plated external threads with the reduced lead on the material having strength as high as 1270MPa. The model can provide useful suggestions for the design of fasteners for aerospace, which are required to satisfy severe requirements of fatigue strengths and dimensions.

  15. LANL's near-real-time measurement control bolt-on to LANMAS

    SciTech Connect

    Hicks, Ruel D; Boyle, Caroline M

    2010-01-01

    Los Alamos National Laboratory (LANL) has created a near-real-time Measurement Control Program (MCP) that integrates with Local Area Network Material Accounting System (LANMAS). The program was designed to take the place of an aging accounting system at LANL which incorporated the measurement control. LANL's Material Control and Accountability (MC&A) group developed many bolt-on features to enhance LANMAS called LAM CAS (Los Alamos Material Control and Accounting System), one of those bolt-on enhancements was to develop the MCP to replace the previous version. MCP was developed with the multiple end-user groups in mind by creating a near-real-time system that was user friendly, provided access controls, and account status of the measurement control systems.

  16. On the performance of Usain Bolt in the 100 m sprint

    NASA Astrophysics Data System (ADS)

    Hernández Gómez, J. J.; Marquina, V.; Gómez, R. W.

    2013-09-01

    Many university texts on mechanics consider the effect of air drag force, using the slowing down of a parachute as an example. Very few discuss what happens when the drag force is proportional to both u and u2. In this paper we deal with a real problem to illustrate the effect of both terms on the speed of a runner: a theoretical model of the world-record 100 m sprint of Usain Bolt during the 2009 World Championships in Berlin is developed, assuming a drag force proportional to u and to u2. The resulting equation of motion is solved and fitted to the experimental data obtained from the International Association of Athletics Federations, which recorded Bolt's position with a laser velocity guard device. It is worth noting that our model works only for short sprints.

  17. Analysis of a Preloaded Bolted Joint in a Ceramic Composite Combustor

    NASA Technical Reports Server (NTRS)

    Hissam, D. Andy; Bower, Mark V.

    2003-01-01

    This paper presents the detailed analysis of a preloaded bolted joint incorporating ceramic materials. The objective of this analysis is to determine the suitability of a joint design for a ceramic combustor. The analysis addresses critical factors in bolted joint design including preload, preload uncertainty, and load factor. The relationship between key joint variables is also investigated. The analysis is based on four key design criteria, each addressing an anticipated failure mode. The criteria are defined in terms of margin of safety, which must be greater than zero for the design criteria to be satisfied. Since the proposed joint has positive margins of safety, the design criteria are satisfied. Therefore, the joint design is acceptable.

  18. Spheroidizing of medium carbon steels

    NASA Astrophysics Data System (ADS)

    O'Brien, James Michael

    2000-11-01

    An investigation has been made of spheroidization of medium carbon steels used in the bolt industry. Two process cycles were considered. One was the intercritical cycle, widely used in industry, in which the steel was heated above the A1 temperature for approximately 2 hours and then cooled to 688°C (1270°F) and held for various periods. The other was a subcritical cycle that involved heating to 704°C (1300°F) for various times. Wire samples were 0.4-in. diameter AISI 1541, considered high in manganese and difficult to spheroidize. Although AISI 4037 is considered easier to spheroidize, this alloy was also tested due to its extensive industrial use. It was found that the intercritical cycle produced a somewhat faster drop in hardness. However, one hour of the subcritical cycle yielded greater ductility than 32 hours of the intercritical process, as measured by tensile tests. Similar ductility results were achieved using a new flare test. The level of spheroidization was defined in this study to be the percentage of carbide particles with aspect ratios less than 3. The subcritical cycle produced the same level of spheroidization in 1/2 hour as that reached by the intercritical cycle in 32 hours. Faster spheroidization of cementite plates in the subcritical process appears to be due to the fine pearlite generated by the current practice of rapid cooling off the hot mill. This advantage is lost in the intercritical process because the original pearlite is dissolved above the A1 temperature.

  19. Stress Analysis of Bolted, Segmented Cylindrical Shells Exhibiting Flange Mating-Surface Waviness

    NASA Technical Reports Server (NTRS)

    Knight, Norman F., Jr.; Phillips, Dawn R.; Raju, Ivatury S.

    2009-01-01

    Bolted, segmented cylindrical shells are a common structural component in many engineering systems especially for aerospace launch vehicles. Segmented shells are often needed due to limitations of manufacturing capabilities or transportation issues related to very long, large-diameter cylindrical shells. These cylindrical shells typically have a flange or ring welded to opposite ends so that shell segments can be mated together and bolted to form a larger structural system. As the diameter of these shells increases, maintaining strict fabrication tolerances for the flanges to be flat and parallel on a welded structure is an extreme challenge. Local fit-up stresses develop in the structure due to flange mating-surface mismatch (flange waviness). These local stresses need to be considered when predicting a critical initial flaw size. Flange waviness is one contributor to the fit-up stress state. The present paper describes the modeling and analysis effort to simulate fit-up stresses due to flange waviness in a typical bolted, segmented cylindrical shell. Results from parametric studies are presented for various flange mating-surface waviness distributions and amplitudes.

  20. [cDNA-AFLP analysis on transcripts associated with bolting in Brassica rapa L. ssp. pekinensis].

    PubMed

    Zou, Yan-Min; Yu, Shuan-Cang; Zhang, Feng-Lan; Yu, Yang-Jun; Zhao, Xiu-Yun; Zhang, De-Shuang

    2009-07-01

    Premature bolting, caused by low temperature in spring and summer cultivation in low land and high land respectively, leads to reduction of the yield and quality of the harvested products in Chinese cabbage. Therefore, exploring genes involved in vernalization response is important to the improvement of Chinese cabbage varieties. Here, one extremely early bolting line (DH-54) and one extremely late bolting line (DH-43) were employed, and the cDNA-AFLP approach was used to identify key components involved in the low-temperature required vernalization response. Of 256 primer recombinations screened, a total of 191 differential expressed transcript-derived fragments (TDFs) were identified, and 82 TDFs were sequenced. BLAST and alignments showed that 52 candidate TDFs shared high levels of similarity with genes of known function, 22 TDFs of unknown function and 8 novel ESTs. The TDFs of known function were involved in genes encoding enzymes working in metabolism, proteins related to stress and defense, signal transduction, and transcription regulation, etc.

  1. A reduced Iwan model that includes pinning for bolted joint mechanics

    DOE PAGES

    Brake, Matthew Robert

    2016-05-12

    Bolted are joints are prevalent in most assembled structures; however, predictive models for the behavior of these joints do not yet exist. Many calibrated models have been proposed to represent the stiffness and energy dissipation characteristics of a bolted joint. In particular, the Iwan model put forth by Segalman and later extended by Mignolet has been shown to be able to predict the response of a jointed structure over a range of excitations once calibrated at a nominal load. The Iwan model, however, is not widely adopted due to the high computational expense of implementing it in a numerical simulation.more » To address this, an analytical, closed form representation of the Iwan model is derived under the hypothesis that upon a load reversal, the distribution of friction elements within the interface resembles a scaled version of the original distribution of friction elements. In conclusion, the Iwan model is extended to include the pinning behavior inherent in a bolted joint.« less

  2. The Load Distribution in Bolted or Riveted Joints in Light-Alloy Structures

    NASA Technical Reports Server (NTRS)

    Vogt, F.

    1947-01-01

    This report contains a theoretical discussion of the load distribution in bolted or riveted joints in light-alloy structures which is applicable not only for loads below the limit of proportionality but also for loads above this limit. The theory is developed for double and single shear joints. The methods given are illustrated by numerical examples and the values assumed for the bolt (or rivet) stiffnesses are based partly on theory and partly on known experimental values. It is shown that the load distribution does not vary greatly with the bolt (or rivet) stiffnesses and that for design purposes it is usually sufficient to know their order of magnitude. The theory may also be directly used for spot-welded structures and, with small modifications, for seam-welded structures, The computational work involved in the methods described is simple and may be completed in a reasonable time for most practical problems. A summary of earlier theoretical and experimental investigations on the subject is included in the report.

  3. Small Loosening of Bolt-nut Fastener Due to Micro Bearing-Surface Slip: A Finite Element Method Study

    NASA Astrophysics Data System (ADS)

    Izumi, Satoshi; Kimura, Masatake; Sakai, Shinsuke

    Bolt-nut fasteners are widely used in mechanical structures due to the systems' ease of disassembly for maintenance and their relatively low cost. However, vibration-induced loosening has remained problematic. In this paper, we investigated the mechanisms of the loosening process due to micro bearing-surface slip within the framework of the three-dimensional finite element method (FEM). The results show close agreement with Kasei's experimental results. It is found that the early-stage nut rotation observed experimentally originates from simultaneous bolt-nut rotation induced by the tightening torsion of the bolt and does not correspond to loosening rotation. Therefore, loosening rotation should be defined by the relative rotation angle of the nut with respect to the bolt. It is also found that small loosening is initiated when the vibration force reaches about 50 to 60% of the critical loading necessary for bearing-surface slip. Attention should be paid to the contact state of both bearing and thread surfaces when considering the loosening of bolt-nut tightening systems. Contact states can be classified into three types: complete slip involving no sticking region, micro slip involving no constant-sticking region over a vibration cycle, and localized slip involving a constant-sticking region over a vibration cycle. It is also found that loosening rotation can proceed when either micro slip or complete slip occurs at both the thread and bearing contact surfaces.

  4. Planned complex suicide by penetrating captive-bolt gunshot and hanging: case study and review of the literature.

    PubMed

    Viel, Guido; Schröder, Ann Sophie; Püschel, Klaus; Braun, Christian

    2009-05-30

    Captive-bolt guns or slaughterer's guns are devices widely used in meat industry and private farmer households for slaughtering animal stocks. They consist of a simple cylindrical metal tube (barrel) with a metal bolt placed in their centre (around 9-15cm long and 1-1.5cm wide). The bolt is actuated by a trigger pull and is propelled forward by compressed air or by the discharge of a blank powder gun cartridge. Violent deaths inflicted by captive-bolt guns are rarely encountered in forensic practice and are predominantly suicidal events. We report an unusual complex suicide by hanging and self-shooting with a slaughterer's gun in a 21-year-old boy. The victim after putting a ceiling fixed rope around his neck shot himself in the head (occipital region) with a Kerner captive-bolt gun. He used two mirrors (a cosmetic mirror and a man-sized one) in order to properly visualize his back and to target the occipital region of his head. Radiological data (computed tomography with three dimensional reconstruction) and autopsy findings are discussed according to the clinical and forensic literature. A brief review on planned complex suicides is also given.

  5. Thermodynamics of Taub-NUT/bolt black holes in Einstein-Maxwell gravity

    SciTech Connect

    Dehghani, M.H.; Khodam-Mohammadi, A.

    2006-06-15

    First, we construct the Taub-NUT/bolt solutions of (2k+2)-dimensional Einstein-Maxwell gravity, when all the factor spaces of 2k-dimensional base space B have positive curvature. These solutions depend on two extra parameters, other than the mass and the NUT charge. These are electric charge q and electric potential at infinity V. We investigate the existence of Taub-NUT solutions and find that in addition to the two conditions of uncharged NUT solutions, there exist two extra conditions. These two extra conditions come from the regularity of vector potential at r=N and the fact that the horizon at r=N should be the outer horizon of the NUT charged black hole. We find that the NUT solutions in 2k+2 dimensions have no curvature singularity at r=N, when the 2k-dimensional base space is chosen to be CP{sup 2k}. For bolt solutions, there exists an upper limit for the NUT parameter which decreases as the potential parameter increases. Second, we study the thermodynamics of these spacetimes. We compute temperature, entropy, charge, electric potential, action and mass of the black hole solutions, and find that these quantities satisfy the first law of thermodynamics. We perform a stability analysis by computing the heat capacity, and show that the NUT solutions are not thermally stable for even k's, while there exists a stable phase for odd k's, which becomes increasingly narrow with increasing dimensionality and wide with increasing V. We also study the phase behavior of the 4 and 6 dimensional bolt solutions in canonical ensemble and find that these solutions have a stable phase, which becomes smaller as V increases.

  6. Recent code studies of RLA, BOLT, and the 100 MV diode

    SciTech Connect

    Poukey, J.W.

    1992-02-01

    The 2-D code MAGIC and TRAJ have been used for extensive studies of diode, IFR channel, and accelerating gap problems in the recirculating linear accelerator (RLA). Typical beam parameters use 10--20 kA, 3--4 MeV. This report summarizes recent results from these simulations. We have also designed possible injectors for the proposed BOLT experiment, with typical beams at 100 A, 1.0--1.5 MeV. Finally, we discuss some preliminary diode runs of proposed 100 MV, 500 kA accelerator using the SMILE/HERMES method of adding voltages from many cavities across a single immersed diode gap. 8 refs.

  7. Numerical and experimental analysis on load sharing & optimization of the joint parameters of polymer composite multi bolted joints

    NASA Astrophysics Data System (ADS)

    Latha Shankar, B.; Sudeep Kumar, T.; Shiva Shankar, G. S.

    2016-09-01

    In the present work, the bearing failure of composite bolted connections of composite laminates was analysed both experimentally and numerically. The glass fiber woven mat 600GSM/ epoxy composite laminates were prepared using wet-layup technique. The process parameters were taken care during preparation of laminates. Examination is done for various estimations of edge-to-hole diameter and width-to-hole diameter proportion. Stress is evaluated in laminates by utilizing Hart-Smith criteria. Ideal estimation of e/d proportion, d/w proportion is recommended for most extreme effectiveness. A numerical technique is utilized for the rough determination of a load shared by bolts in a numerous "bolted" joints loaded in tension were investigated experimentally and numerically. The effect of un-evenness in load shearing is suggested.

  8. VALIDITY OF THE HIGH-TENSILE-STRENG TH BOLT FOR THE SOFT ROCK WITH LARGE CROSS SECTIONAL TUNNEL

    NASA Astrophysics Data System (ADS)

    Yagi, Hiroshi; Tamamura, Kouji; Uneda, Atsushi; Domon, Tsuyoshi; Nishimura, Kazuo

    This paper reports the experiential result about the applications of the high tensile strength bolts as a countermeasure for the displacement, considered about the denaturalization of the large cross sectional tunnel in mudstone layer. In Kanaya Tunnel of the New Tomei Expressway, the soft rock section appeared where we cannot restrain support denaturizi ng and internal displacement by materials of the standard design. Then fore, we adopted the high tensile strength bolts (748kN) replacing with of the standard design, and improved the support proof for stress. As the result, we got possible to control the displacement and execute the work safety and economi cally. We compared the analysis result (FEM) by the limited element method with the measure result on the spot, and inspected the supportability effect of the higt tensile strength bolts.

  9. Study, Development, and Design of Replaceable Shear Yielding Steel Panel Damper

    SciTech Connect

    Murakami, Katsuhide; Keii, Michio

    2008-07-08

    For middle-high rise buildings, vibration controlled structures to reduce the damage of main frames are recently becoming general in Japan. A steel material damper is low price and excellent in the energy absorption efficiency at a large earthquake. Though the exchange of the dampers are necessary when an excessive accumulation of plasticity deformation occurs, a steel material damping system, which received an excessive accumulation of plasticity deformation after a large earthquake, can recover a seismic-proof performance and property value of the building after the replacement. In the paper, shear yielding steel panel dampers installed in the web of a beam connected with high tension bolt joint is introduced. This damper is made of low-yield point steel, and the advantages of this system are low cost, easy-production and easy-replacement. For this steel panel damper, the finite element method (FEM) analysis using the shell element model adjusted to 1/2 of 6.4 m beam span is executed to make the design most effective. Yielding property of the beam installing this damper, shape of the splice plate and the bolt orientation for the connecting are examined in this analysis. As a result, we found that the plastic strain extends uniformly to the entire damping panel when making the splice plate a trapezoidal shape. The basic performance confirmation examination was also done using the real scale examination model besides the FEM analysis, and the performance of the system was confirmed. In addition, design of a high rise building in which the steel shear-yielding panel dampers and oil dampers were adopted without disturbing an architectural plan is also introduced.

  10. Retropatellar nailing and condylar bolts for complex fractures of the tibial plateau: technique, pilot study and rationale.

    PubMed

    Garnavos, Christos

    2014-07-01

    In a previous study, condylar compression bolts and intramedullary nailing with the use of a traditional transpatellar tendon approach were employed for the management of non-impacted complex fractures of the tibia plateau. However, there were intra-operative difficulties, related to the surgical approach that could jeopardise fracture reduction and contribute to sub-optimal outcomes. The purpose of this study is to introduce the retropatellar approach for the management of complex tibial plateau fractures with intramedullary nailing and condylar compression bolts that avoid the pitfalls created by the traditional transpatellar approach.

  11. Acoustics and its relation to language: The influence of Dick Bolt

    NASA Astrophysics Data System (ADS)

    Stevens, Kenneth N.

    2003-04-01

    Under the mentoring of Dick Bolt, and the stimulation he provided in the Acoustics Laboratory at MIT, many students were exposed to a range of topics in acoustics, including mechanisms of sound generation, radiation, and propagation, noise control, acoustics of resonators and rooms, human responses to sound, and speech perception under various adverse conditions. As someone who became interested in speech communication, I have recognized that this kind of quantitative background in acoustics is an important requirement for developing models of how humans produce speech, how they perceive and understand speech, and how children acquire these skills. Speech production involves sound sources produced by a nonlinear mechanical system and by noise arising from turbulent airflow. Sound is propagated in a vocal tract with yielding walls, and acoustic coupling is introduced by lossy resonators attached to the vocal tract, including the trachea and the nasal cavity. These acoustic principles of sound generation create an inventory of sound types that give rise to distinctive responses in the ears and brains of listeners. The solid grounding in acoustics provided by Dick Bolt and his leadership have helped in the formation of this linkage between acoustics, speech physiology, linguistics, and human perception.

  12. Design and Demonstration of Bolt Retractor Separation System for X-38 Deorbit Propulsion Stage

    NASA Technical Reports Server (NTRS)

    Ahmed, Raf; Johnston, A. S.; Garrison, J. C.; Gaines, J. L.; Waggoner, J. D.

    2003-01-01

    A separation system was designed for the X-38 experimental crew return vehicle program to allow the Deorbit Propulsion Stage (DPS) to separate from the X-38 lifting body during reentry operations. The configuration chosen was a spring-loaded plunger, known as the Bolt Retractor Subsystem (BRS), that retracts each of the six DPS-to-lifting body attachment bolts across the interface plane after being triggered by a separation nut mechanism. The system was designed to function on the ground in an atmospheric environment as well as in space. The BRS provides the same functionality as that of a completely pyrotechnic shear separation system that would normally be considered ideal for this application, but at a much lower cost. This system also could potentially be applied to future space station crew return vehicles. The design goal of 40 ms retraction time was successfully met in a series of demonstrations performed at the NASA Marshall Space Flight Center s Pyrotechnic Shock Facility (PSF) and Flight Robotics Laboratory (FRL). It must be emphasized that a full-scale test series was not performed on the BRS due to program schedule and cost constraints.

  13. Professor Usain Bolt Welcomes You to the Schoolyard: Physics for Champions

    NASA Astrophysics Data System (ADS)

    Vourlias, Kostas; Seroglou, Fanny

    2016-01-01

    Could Usain Bolt achieve what teachers often fail to do? Could this famous Olympic winner challenge and motivate students to study mechanics and introduce them to the principles of physics in a fun way, outside of the classroom? In order to answer these questions, we "invited" for one semester the world record holder to visit our Greek high school in Thessaloniki as a guest teacher. For 13 weeks, 27 fifteen-year-olds run (or at least try to run) side by side with this great athlete, intending to learn his secrets. Within 9.58 s or 100 m, students have the chance to study a "phenomenon" of their daily lives and be introduced to a variety of concepts of physics in a pleasant and effective way. Students use simple athletic and innovative biomechanical equipment for their experiments, but mostly their own bodies, as experimental tools in order to study and to "feel" physics. Students have the chance to compare their athletic abilities to Bolt's and confront some of their ideas concerning concepts of physics.

  14. Experimental data on single-bolt joints in quasi isotropic graphite/polyimide laminates

    NASA Technical Reports Server (NTRS)

    Wichorek, G. R.

    1982-01-01

    Sixteen ply, quasi-isotropic laminates of Celanese Celion 6000/PMR-15 and Celion 6000/LARC-160 with a fiber orientation of (0/45/90/-45) sub 2S were evaluated. Tensile and open hole specimens were tested at room temperature to establish laminate tensile strength and net tensile strength at an unloaded bolt hole. Double lap joint specimens with a single 4.83-mm (0.19 in.) diameter bolt torqued to 1.7 N-m (15 lbf-in.) were tested in tension at temperatures of 116 K (-250F), 297 K (75F), and 589 K (600F). The joint ratios of w/d (specimen width to hole diameter) and e/d (edge distance to hole diameter) were varied from 4 to 6 and from 2 to 4, respectively. The effect of joint geometry and temperature on failure mode and joint stresses are shown. Joint stresses calculated at maximum load for each joint geometry and test temperature are reported. Joint strength in net tension, bearing, and shear out at 116 K (-250F), 297 K (75F), and 589 K (600F) are given for the Celion 6000/PMR-15 and Celion 6000/LARC-160 laminates.

  15. A real-time visual inspection method of fastening bolts in freight car operation

    NASA Astrophysics Data System (ADS)

    Nan, Guo; Yao, JunEn

    2015-10-01

    A real-time inspection of the key components is necessary for ensuring safe operation of freight car. While traditional inspection depends on the trained human inspectors, which is time-consuming and lower efficient. With the development of machine vision, vision-based inspection methods get more railway on-spot applications. The cross rod end fastening bolts are important components on both sides of the train body that fixing locking plates together with the freight car main structure. In our experiment, we get the images containing fastening bolt components, and accurately locate the locking plate position using a linear Support Vector Machine (SVM) locating model trained with Histograms of Oriented Gradients (HOG) features. Then we extract the straight line segment using the Line Segment Detector (LSD) and encoding them in a range, which constitute a straight line segment dataset. Lastly we determine the locking plate's working state by the linear pattern. The experiment result shows that the localization accurate rate is over 99%, the fault detection rate is over 95%, and the module implementation time is 2f/s. The overall performance can completely meet the practical railway safety assurance application.

  16. Directional Control-Response Compatibility Relationships Assessed by Physical Simulation of an Underground Bolting Machine

    PubMed Central

    Steiner, Lisa; Burgess-Limerick, Robin; Porter, William

    2015-01-01

    Objective The authors examine the pattern of direction errors made during the manipulation of a physical simulation of an underground coal mine bolting machine to assess the directional control-response compatibility relationships associated with the device and to compare these results to data obtained from a virtual simulation of a generic device. Background Directional errors during the manual control of underground coal roof bolting equipment are associated with serious injuries. Directional control-response relationships have previously been examined using a virtual simulation of a generic device; however, the applicability of these results to a specific physical device may be questioned. Method Forty-eight participants randomly assigned to different directional control-response relationships manipulated horizontal or vertical control levers to move a simulated bolter arm in three directions (elevation, slew, and sump) as well as to cause a light to become illuminated and raise or lower a stabilizing jack. Directional errors were recorded during the completion of 240 trials by each participant. Results Directional error rates are increased when the control and response are in opposite directions or if the direction of the control and response are perpendicular. The pattern of direction error rates was consistent with experiments obtained from a generic device in a virtual environment. Conclusion Error rates are increased by incompatible directional control-response relationships. Application Ensuring that the design of equipment controls maintains compatible directional control-response relationships has potential to reduce the errors made in high-risk situations, such as underground coal mining. PMID:24689255

  17. Mechanical Model of Steel-concrete Composite Joint under Sagging Bending Moment

    NASA Astrophysics Data System (ADS)

    Pisarek, Zdzisław

    2012-06-01

    In buildings with steel-concrete composite floors, joints are designed to transmit mainly hogging bending moment. In case of the large horizontal loads due to wind, earthquake or accidental events, sagging bending moments in a joint can also occur. Additionally, large deformations of the structure cause tying and prying effects. In the paper, a mechanical model based on "component method" for evaluation of characteristics of the composite joint is presented. The influence of tying and prying actions on distribution of the internal forces in a joint is also analyzed. The procedure for calculation of the characteristics of the composite joint with bolted endplate connection is elaborated too.

  18. Turning caring into business: the nuts and bolts of starting a private-duty home care business.

    PubMed

    Smith, Cheryl

    2007-10-01

    As baby boomers age and home care grows in popularity as an alternative to institutionalized care, opportunities abound for entrepreneurs to meet the demand through professional private-duty businesses. This article examines the nuts and bolts of launching and operating a successful private-duty agency.

  19. Thermal conductance measurements of bolted copper to copper joints at sub-Kelvin temperatures

    NASA Astrophysics Data System (ADS)

    Didschuns, I.; Woodcraft, A. L.; Bintley, D.; Hargrave, P. C.

    2004-05-01

    We have measured the thermal contact conductance of several demountable copper joints below 1 K. Joints were made by bolting together either two flat surfaces or a clamp around a rod. Surfaces were gold plated, and no intermediate materials were used. A linear dependence on temperature was seen. Most of the measured conductance values fell into a narrow range: 0.1-0.2 W K -1 at 1 K. Results in the literature for similar joints consist of predictions based on electrical resistance measurements using the Wiedemann-Franz law. There is little evidence of the validity of this law in the case of joints. Nevertheless, our results are in good agreement with the literature predictions, suggesting that such predictions are a reasonable approximation.

  20. 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.

  1. Design and fabrication of graphite-epoxy bolted wing skin splice specimens

    NASA Technical Reports Server (NTRS)

    Johnson, R. W.; Mccarty, J. E.

    1977-01-01

    Graphite-epoxy bolted joint specimens were designed and fabricated. These specimens were to be representative of a side-of-body wing skin splice with a 20-year life expectancy in a commercial transport environment. Preliminary tests were performed to determine design values of bearing and net tension stresses. Based upon the information developed, a three-fastener-wide representative wing skin splice was designed for a load of 2627 KN/m (15,000 lbf/in.). One joint specimen was fabricated and tested at NASA. The wing skin splice failed at 106 percent of design ultimate load. This joint design achieved all static load objectives. Fabrication of six specimens, together with their loading fixtures, was completed, and the specimens were delivered to NASA-LRC.

  2. Numerical design and test on an assembled structure of a bolted joint with viscoelastic damping

    NASA Astrophysics Data System (ADS)

    Hammami, Chaima; Balmes, Etienne; Guskov, Mikhail

    2016-03-01

    Mechanical assemblies are subjected to many dynamic loads and modifications are often needed to achieve acceptable vibration levels. While modifications on mass and stiffness are well mastered, damping modifications are still considered difficult to design. The paper presents a case study on the design of a bolted connection containing a viscoelastic damping layer. The notion of junction coupling level is introduced to ensure that sufficient energy is present in the joints to allow damping. Static performance is then addressed and it is shown that localization of metallic contact can be used to meet objectives, while allowing the presence of viscoelastic materials. Numerical prediction of damping then illustrates difficulties in optimizing for robustness. Modal test results of three configurations of an assembled structure, inspired by aeronautic fuselages, are then compared to analyze the performance of the design. While validity of the approach is confirmed, the effect of geometric imperfections is shown and stresses the need for robust design.

  3. ASP (AntiSubmarine Penetrator) base plate redesign and explosive bolt test

    SciTech Connect

    Cole, J.K.; Wolfe, W.P.

    1988-10-01

    This report presents the results of a post-flight investigation of the Rocket Antisubmarine Penetrator (RAP) tests of the AntiSubmarine Penetrator (ASP). It focuses on the cause for the premature deployment of the on-board recovery system and the failure of the base pressure transducers. As a result of the investigation, the base plate of the ASP vehicle was modified to increase its structural stiffness. Also, an instrumented test was conducted to assess the environment that is created when the three explosive bolts are activated to separate the vehicle from the interstage adapter and the rocket booster. The results of this test are presented and discussed. 5 refs., 15 figs.

  4. Crystalline capsules: metal-organic frameworks locked by size-matching ligand bolts.

    PubMed

    Wang, Hao; Xu, Jian; Zhang, Da-Shuai; Chen, Qiang; Wen, Rong-Mei; Chang, Ze; Bu, Xian-He

    2015-05-11

    Metal-organic frameworks (MOFs) are shown to be good examples of a new class of crystalline porous materials for guest encapsulation. Since the encapsulation/release of guest molecules in MOF hosts is a reversible process in nature, how to prevent the leaching of guests from the open pores with minimal and nondestructive modifications of the structure is a critical issue. To address this issue, we herein propose a novel strategy of encapsulating guests by introducing size-matching organic ligands as bolts to lock the pores of the MOFs through deliberately anchoring onto the open metal sites in the pores. Our proposed strategy provides a mechanical way to prevent the leaching of guests and thereby has less dependence on the specific chemical environment of the hosts, thus making it applicable for a wide variety of existing MOFs once the size-matching ligands are employed.

  5. Thermodynamic volumes for AdS-Taub-NUT and AdS-Taub-Bolt

    NASA Astrophysics Data System (ADS)

    Johnson, Clifford V.

    2014-12-01

    In theories of semi-classical quantum gravity where the cosmological constant is considered a thermodynamic variable, the gravitational mass of a black hole has been shown to correspond to the enthalpy of the thermodynamic system, rather than the energy. We propose that this should be extended to all spacetime solutions, and consider the meaning of this extension of gravitational thermodynamics for the Taub-NUT and Taub-Bolt geometries in four dimensional locally anti-de Sitter spacetime. We present formulae for their thermodynamic volumes. Surprisingly, Taub-NUT has negative volume, for which there is a natural dynamical explanation in terms of the process of formation of the spacetime. A special case corresponds to pure AdS4 with an S3 slicing. The same dynamical setting can explain the negative entropy known to exist for these solutions for a range of parameters.

  6. Failure behavior for composite single-bolted joints in double shear tension

    NASA Astrophysics Data System (ADS)

    Tang, Zhanwen; Liu, Hanyang; Yang, Zhiyong; Shi, Hanqiao; Sun, Baogang

    2016-05-01

    In order to improve the reliability and load carrying capacity of composite laminates structures which were lap jointed by bolt, in this paper, the failure strength and failure mode of laminated composite pinned-joints is investigated. To determine the effects of joint geometry and stacking sequence on the bearing strength and damage mode, the multi-scale numerical model combining with the Generalized Method of Cells (GMC) and considering the failure and the damage of constituent materials was created based on the ABAQUS and its user subroutine (USDFLD). A three-dimensional finite element technique was used for the stress analysis. Based on the three-dimensional state of stress of each element, different failure modes were detected by the failure theories of constituent materials, all of which are applied at the fiber, matrix and fiber-matrix interface constituent level. Numerical simulations have been carried out by which edge distance-to-hole diameter ratio, and plate width-to-hole diameter ratio are varied, The composite laminated plates are stacked with the following four different orientations: [+45/-45]2s, [90/+45/-45]s, and [0/90/0]s, the results show that failure mode and bearing strength are closely related to by stacking sequence of plates and geometrical parameters. Finally, the ultimate strength and failure modes of composite bolted joints in static tension double-shear loading conditions are predicted by using the progressive damage method established and the effects of layup and dimension of laminates on the properties of the connection structure were researched in this paper. An excellent agreement is found between data obtained from this study and the experiment.

  7. Torque Limit for Bolted Joint for Composites. Part A; TTTC Properties of Laminated Composites

    NASA Technical Reports Server (NTRS)

    Zhao, Yi

    2003-01-01

    The existing design code for torque limit of bolted joints for composites at Marshall Space Flight Center is MSFC-STD-486B, which was originally developed in 1960s for metallic materials. The theoretical basis for this code was a simplified mechanics analysis, which takes into account only the bolt, nut and washers, but not the structural members to be connected. The assumption was that metallic materials would not fail due to the bearing stress at the contact area between washer and the mechanical member. This is true for metallic materials; but for composite materials the results could be completely different. Unlike most metallic materials, laminated composite materials have superior mechanical properties (such as modulus and strength) in the in-plane direction, but not in the out-of-plane, or through-the-thickness (TTT) direction. During the torquing, TTT properties (particularly compressive modulus and compressive strength) play a dominant role in composite failure. Because of this concern, structural design engineers at Marshall are currently using a compromised empirical approach: using 50% of the torque value for composite members. Companies like Boeing is using a similar approach. An initial study was conducted last summer on this topic to develop theoretical model(s) that takes into consideration of composite members. Two simplified models were developed based on stress failure criterion and strain failure criterion, respective. However, these models could not be used to predict the torque limit because of the unavailability of material data, specifically, through-the-thickness compression (TTTC) modulus and strength. Therefore, the task for this summer is to experimentally determine the TTTC properties. Due to the time limitation, only one material has been tested: IM7/8552 with [0 degrees,plus or minus 45 degrees, 90 degree ] configuration. This report focuses the test results and their significance, while the experimentation will be described in a

  8. Taub-NUT/bolt black holes in Gauss-Bonnet-Maxwell gravity

    SciTech Connect

    Dehghani, M.H.; Hendi, S. H.

    2006-04-15

    We present a class of higher-dimensional solutions to Gauss-Bonnet-Maxwell equations in 2k+2 dimensions with a U(1) fibration over a 2k-dimensional base space B. These solutions depend on two extra parameters, other than the mass and the Newman-Unti-Tamburino charge, which are the electric charge q and the electric potential at infinity V. We find that the form of metric is sensitive to geometry of the base space, while the form of electromagnetic field is independent of B. We investigate the existence of Taub-Newman-Unti-Tamburino/bolt solutions and find that in addition to the two conditions of uncharged Newman-Unti-Tamburino solutions, there exist two other conditions. These two extra conditions come from the regularity of vector potential at r=N and the fact that the horizon at r=N should be the outer horizon of the black hole. We find that for all nonextremal Newman-Unti-Tamburino solutions of Einstein gravity having no curvature singularity at r=N, there exist Newman-Unti-Tamburino solutions in Gauss-Bonnet-Maxwell gravity. Indeed, we have nonextreme Newman-Unti-Tamburino solutions in 2+2k dimensions only when the 2k-dimensional base space is chosen to be CP{sup 2k}. We also find that the Gauss-Bonnet-Maxwell gravity has extremal Newman-Unti-Tamburino solutions whenever the base space is a product of 2-torii with at most a 2-dimensional factor space of positive curvature, even though there a curvature singularity exists at r=N. We also find that one can have bolt solutions in Gauss-Bonnet-Maxwell gravity with any base space. The only case for which one does not have black hole solutions is in the absence of a cosmological term with zero curvature base space.

  9. Thermal Stress Cracking of Slide-Gate Plates in Steel Continuous Casting

    NASA Astrophysics Data System (ADS)

    Lee, Hyoung-Jun; Thomas, Brian G.; Kim, Seon-Hyo

    2016-04-01

    The slide-gate plates in a cassette assembly control the steel flow through the tundish nozzle, and may experience through-thickness cracks, caused by thermal expansion and/or mechanical constraint, leading to air aspiration and safety concerns. Different mechanisms for common and rare crack formation are investigated with the aid of a three-dimensional finite-element model of thermal mechanical behavior of the slide-gate plate assembly during bolt pretensioning, preheating, tundish filling, casting, and cooling stages. The model was validated with previous plant temperature measurements of a ladle plate during preheating and casting, and then applied to a typical tundish-nozzle slide-gate assembly. The formation mechanisms of different types of cracks in the slide-gate plates are investigated using the model and evaluated with actual slide-gate plates at POSCO. Common through-thickness radial cracks, found in every plate, are caused during casting by high tensile stress on the outside surfaces of the plates, due to internal thermal expansion. In the upper plate, these cracks may also arise during preheating or tundish filling. Excessive bolt tightening, combined with thermal expansion during casting may cause rare radial cracks in the upper and lower plates. Rare radial and transverse cracks in middle plate appear to be caused during tundish filling by impingement of molten steel on the middle of the middle plate that generates tensile stress in the surrounding refractory. The mechanical properties of the refractory, the bolt tightening conditions, and the cassette/plate design are all important to service life.

  10. Ultrahigh carbon steels, Damascus steels, and superplasticity

    SciTech Connect

    Sherby, O.D.; Wadsworth, J.

    1997-04-01

    The processing properties of ultrahigh carbon steels (UHCSs) have been studied at Stanford University over the past twenty years. These studies have shown that such steels (1 to 2.1% C) can be made superplastic at elevated temperature and can have remarkable mechanical properties at room temperature. It was the investigation of these UHCSs that eventually brought us to study the myths, magic, and metallurgy of ancient Damascus steels, which in fact, were also ultrahigh carbon steels. These steels were made in India as castings, known as wootz, possibly as far back as the time of Alexander the Great. The best swords are believed to have been forged in Persia from Indian wootz. This paper centers on recent work on superplastic UHCSs and on their relation to Damascus steels. 32 refs., 6 figs.

  11. TEST AND ANALYSIS ON THE PROGRESSIVE COLLAPSE OF STEEL TRUSSES UNDER CYCLIC LOADING

    NASA Astrophysics Data System (ADS)

    Imase, Fumiaki; Usami, Tsutomu; Funayama, Jyunki; Wang, Chun-Lin

    The objective of this study is to examine experimentally and analytically the damage progress of steel truss structures in cyclic loadings. The adequacy of a numerical model developed in the past study for analyzing truss structures under cyclic or dynamic loadings is examined in view of the test results of model truss structures. Seven steel truss specimens whose panel points are rigidly connected through gusset plates by high-tension bolts were tested under constant vertical loads and cyclically increasing horizontal loads. Two truss models equipped with buckling restrained braces as diagonal members were tested. Moreover, elastic-plastic large displacement analysis is executed with appropriate modeling of test truss structures and with initial lateral loads simulating initial imperfections. In many cases, good correlation between test and analysis is observed up to the points where local bolt hole damages appear near the lower panel points of test truss structures. In addition an analytical model that can examine the up-lift effect of a base plate on the hinge-support has been proposed to improve the analytical modeling.

  12. A clamping force measurement system for monitoring the condition of bolted joints on railway track joints and points

    NASA Astrophysics Data System (ADS)

    Tesfa, B.; Horler, G.; Thobiani, F. Al; Gu, F.; Ball, A. D.

    2012-05-01

    Many industrial structures associated with railway infrastructures rely on a large number of bolted joint connections to ensure safe and reliable operation of the track and trackside furniture. Significant sums of money are spent annually to repair the damage caused by bolt failures and to maintain the integrity of bolted structures. In the UK, Network Rail (the organization responsible for rail network maintenance and safety) conducts corrective and preventive maintenance manually on 26,000 sets of points (each having approximately 30 bolted joints per set), in order to ensure operational success and safety for the travelling public. Such manual maintenance is costly, disruptive, unreliable and prone to human error. The aim of this work is to provide a means of automatically measuring the clamping force of each individual bolted joint, by means of an instrumented washer. This paper describes the development of a sensor means to be used in the washer, which satisfies the following criteria. Sense changes in the clamping force of the joint and report this fact. Provide compatibility with the large dynamic range of clamping force. Satisfy the limitations in terms of physical size. Provide the means to electronically interface with the washer. Provide a means of powering the washer in situ. Provide a solution at an acceptable cost. Specifically the paper focuses on requirements 1, 2 and 3 and presents the results that support further development of the proposed design and the realization of a pre-prototype system. In the paper, various options for the force sensing element (strain gage, capacitor, piezo-resistive) have been compared, using design optimization techniques. As a result of the evaluation, piezo-resistive sensors in concert with a proprietary force attenuation method, have been found to offer the best performance and cost trade-off The performance of the novel clamping force sensor has been evaluated experimentally and the results show that a smart washer

  13. Identification of bolting-related microRNAs and their targets reveals complex miRNA-mediated flowering-time regulatory networks in radish (Raphanus sativus L.)

    PubMed Central

    Nie, Shanshan; Xu, Liang; Wang, Yan; Huang, Danqiong; Muleke, Everlyne M.; Sun, Xiaochuan; Wang, Ronghua; Xie, Yang; Gong, Yiqin; Liu, Liwang

    2015-01-01

    MicroRNAs (miRNAs) play vital regulatory roles in plant growth and development. The phase transition from vegetative growth to flowering is crucial in the life cycle of plants. To date, miRNA-mediated flowering regulatory networks remain largely unexplored in radish. In this study, two small RNA libraries from radish leaves at vegetative and reproductive stages were constructed and sequenced by Solexa sequencing. A total of 94 known miRNAs representing 21 conserved and 13 non-conserved miRNA families, and 44 potential novel miRNAs, were identified from the two libraries. In addition, 42 known and 17 novel miRNAs were significantly differentially expressed and identified as bolting-related miRNAs. RT-qPCR analysis revealed that some miRNAs exhibited tissue- or developmental stage-specific expression patterns. Moreover, 154 target transcripts were identified for 50 bolting-related miRNAs, which were predominately involved in plant development, signal transduction and transcriptional regulation. Based on the characterization of bolting-related miRNAs and their target genes, a putative schematic model of miRNA-mediated bolting and flowering regulatory network was proposed. These results could provide insights into bolting and flowering regulatory networks in radish, and facilitate dissecting the molecular mechanisms underlying bolting and flowering time regulation in vegetable crops. PMID:26369897

  14. Identification of bolting-related microRNAs and their targets reveals complex miRNA-mediated flowering-time regulatory networks in radish (Raphanus sativus L.).

    PubMed

    Nie, Shanshan; Xu, Liang; Wang, Yan; Huang, Danqiong; Muleke, Everlyne M; Sun, Xiaochuan; Wang, Ronghua; Xie, Yang; Gong, Yiqin; Liu, Liwang

    2015-09-15

    MicroRNAs (miRNAs) play vital regulatory roles in plant growth and development. The phase transition from vegetative growth to flowering is crucial in the life cycle of plants. To date, miRNA-mediated flowering regulatory networks remain largely unexplored in radish. In this study, two small RNA libraries from radish leaves at vegetative and reproductive stages were constructed and sequenced by Solexa sequencing. A total of 94 known miRNAs representing 21 conserved and 13 non-conserved miRNA families, and 44 potential novel miRNAs, were identified from the two libraries. In addition, 42 known and 17 novel miRNAs were significantly differentially expressed and identified as bolting-related miRNAs. RT-qPCR analysis revealed that some miRNAs exhibited tissue- or developmental stage-specific expression patterns. Moreover, 154 target transcripts were identified for 50 bolting-related miRNAs, which were predominately involved in plant development, signal transduction and transcriptional regulation. Based on the characterization of bolting-related miRNAs and their target genes, a putative schematic model of miRNA-mediated bolting and flowering regulatory network was proposed. These results could provide insights into bolting and flowering regulatory networks in radish, and facilitate dissecting the molecular mechanisms underlying bolting and flowering time regulation in vegetable crops.

  15. Enhancement of tendon-bone healing via the combination of biodegradable collagen-loaded nanofibrous membranes and a three-dimensional printed bone-anchoring bolt.

    PubMed

    Chou, Ying-Chao; Yeh, Wen-Lin; Chao, Chien-Lin; Hsu, Yung-Heng; Yu, Yi-Hsun; Chen, Jan-Kan; Liu, Shih-Jung

    2016-01-01

    A composite biodegradable polymeric model was developed to enhance tendon graft healing. This model included a biodegradable polylactide (PLA) bolt as the bone anchor and a poly(D,L-lactide-co-glycolide) (PLGA) nanofibrous membrane embedded with collagen as a biomimic patch to promote tendon-bone interface integration. Degradation rate and compressive strength of the PLA bolt were measured after immersion in a buffer solution for 3 months. In vitro biochemical characteristics and the nanofibrous matrix were assessed using a water contact angle analyzer, pH meter, and tetrazolium reduction assay. In vivo efficacies of PLGA/collagen nanofibers and PLA bolts for tendon-bone healing were investigated on a rabbit bone tunnel model with histological and tendon pullout tests. The PLGA/collagen-blended nanofibrous membrane was a hydrophilic, stable, and biocompatible scaffold. The PLA bolt was durable for tendon-bone anchoring. Histology showed adequate biocompatibility of the PLA bolt on a medial cortex with progressive bone ingrowth and without tissue overreaction. PLGA nanofibers within the bone tunnel also decreased the tunnel enlargement phenomenon and enhanced tendon-bone integration. Composite polymers of the PLA bolt and PLGA/collagen nanofibrous membrane can effectively promote outcomes of tendon reconstruction in a rabbit model. The composite biodegradable polymeric system may be useful in humans for tendon reconstruction. PMID:27601901

  16. Enhancement of tendon–bone healing via the combination of biodegradable collagen-loaded nanofibrous membranes and a three-dimensional printed bone-anchoring bolt

    PubMed Central

    Chou, Ying-Chao; Yeh, Wen-Lin; Chao, Chien-Lin; Hsu, Yung-Heng; Yu, Yi-Hsun; Chen, Jan-Kan; Liu, Shih-Jung

    2016-01-01

    A composite biodegradable polymeric model was developed to enhance tendon graft healing. This model included a biodegradable polylactide (PLA) bolt as the bone anchor and a poly(D,L-lactide-co-glycolide) (PLGA) nanofibrous membrane embedded with collagen as a biomimic patch to promote tendon–bone interface integration. Degradation rate and compressive strength of the PLA bolt were measured after immersion in a buffer solution for 3 months. In vitro biochemical characteristics and the nanofibrous matrix were assessed using a water contact angle analyzer, pH meter, and tetrazolium reduction assay. In vivo efficacies of PLGA/collagen nanofibers and PLA bolts for tendon–bone healing were investigated on a rabbit bone tunnel model with histological and tendon pullout tests. The PLGA/collagen-blended nanofibrous membrane was a hydrophilic, stable, and biocompatible scaffold. The PLA bolt was durable for tendon–bone anchoring. Histology showed adequate biocompatibility of the PLA bolt on a medial cortex with progressive bone ingrowth and without tissue overreaction. PLGA nanofibers within the bone tunnel also decreased the tunnel enlargement phenomenon and enhanced tendon–bone integration. Composite polymers of the PLA bolt and PLGA/collagen nanofibrous membrane can effectively promote outcomes of tendon reconstruction in a rabbit model. The composite biodegradable polymeric system may be useful in humans for tendon reconstruction.

  17. Enhancement of tendon–bone healing via the combination of biodegradable collagen-loaded nanofibrous membranes and a three-dimensional printed bone-anchoring bolt

    PubMed Central

    Chou, Ying-Chao; Yeh, Wen-Lin; Chao, Chien-Lin; Hsu, Yung-Heng; Yu, Yi-Hsun; Chen, Jan-Kan; Liu, Shih-Jung

    2016-01-01

    A composite biodegradable polymeric model was developed to enhance tendon graft healing. This model included a biodegradable polylactide (PLA) bolt as the bone anchor and a poly(D,L-lactide-co-glycolide) (PLGA) nanofibrous membrane embedded with collagen as a biomimic patch to promote tendon–bone interface integration. Degradation rate and compressive strength of the PLA bolt were measured after immersion in a buffer solution for 3 months. In vitro biochemical characteristics and the nanofibrous matrix were assessed using a water contact angle analyzer, pH meter, and tetrazolium reduction assay. In vivo efficacies of PLGA/collagen nanofibers and PLA bolts for tendon–bone healing were investigated on a rabbit bone tunnel model with histological and tendon pullout tests. The PLGA/collagen-blended nanofibrous membrane was a hydrophilic, stable, and biocompatible scaffold. The PLA bolt was durable for tendon–bone anchoring. Histology showed adequate biocompatibility of the PLA bolt on a medial cortex with progressive bone ingrowth and without tissue overreaction. PLGA nanofibers within the bone tunnel also decreased the tunnel enlargement phenomenon and enhanced tendon–bone integration. Composite polymers of the PLA bolt and PLGA/collagen nanofibrous membrane can effectively promote outcomes of tendon reconstruction in a rabbit model. The composite biodegradable polymeric system may be useful in humans for tendon reconstruction. PMID:27601901

  18. Structural design of an in-line bolted joint for the space shuttle solid rocket motor case segments

    NASA Technical Reports Server (NTRS)

    Dorsey, John T.; Stein, Peter A.; Bush, Harold G.

    1987-01-01

    Results of a structural design study of an in-line bolted joint concept which can be used to assemble Space Shuttle Solid Rocket Motor (SRM) case segments are presented. Numerous parametric studies are performed to characterize the in-line bolted joint behavior as major design variables are altered, with the primary objective always being to keep the inside of the joint (where the O-rings are located) closed during the SRM firing. The resulting design has 180 1-inch studs, an eccentricity of -0.5 inch, a flange thickness of 3/4 inch, a bearing plate thickness of 1/4 inch, and the studs are subjected to a preload which is 70% of ultimate. The mass penalty per case segment joint for the in-line design is 346 lbm more than the weight penalty for the proposed capture tang fix.

  19. Corrosion Behavior of Medium Carbon Steel in Simulated Concentrated Yucca Mountain Waters

    SciTech Connect

    Yilmaz, A; Chandra, D; Rebak, R B

    2004-04-09

    Medium carbon steel (MCS) is the candidate material for rock bolts to reinforce the borehole liners and emplacement drifts of the proposed Yucca Mountain (YM) high-level nuclear waste repository. Corrosion performance of this structural steel -AISI 1040- was investigated by techniques such as linear polarization, electrochemical impedance spectroscopy (EIS), and laboratory immersion tests in lab simulated concentrated YM ground waters. Corrosion rates of the steel were determined for the temperatures in the range from 25 C to 85 C, for the ionic concentrations of 1 time (1x), 10 times (10x), and hundred times (100x) ground waters. The MCS corroded uniformly at the penetration rates of 35-200 {micro}m/year in the de-aerated YM waters, and 200-1000 {micro}m/year in the aerated waters. Increasing temperatures in the de-aerated waters increased the corrosion rates of the steel. However, increasing ionic concentrations influenced the corrosion rates only slightly. In the aerated 1x and 10x waters, increasing temperatures increased the rates of MCS significantly. Inhibitive precipitates, which formed in the aerated 100x waters at higher temperatures (65 C and up) decreased the corrosion rates to the values that obtained for the de-aerated YM aqueous environments. The steel suffered pitting corrosion in the both de-aerated and aerated hot YM environments after anodic polarization.

  20. Comminuting irradiated ferritic steel

    DOEpatents

    Bauer, Roger E.; Straalsund, Jerry L.; Chin, Bryan A.

    1985-01-01

    Disclosed is a method of comminuting irradiated ferritic steel by placing the steel in a solution of a compound selected from the group consisting of sulfamic acid, bisulfate, and mixtures thereof. The ferritic steel is used as cladding on nuclear fuel rods or other irradiated components.

  1. Development of Thread Rolled Anti-Loosening Bolts Based on the Double Thread Mechanism and a Performance Evaluation

    NASA Astrophysics Data System (ADS)

    Takemasu, Teruie; Miyahara, Hiroshi

    It has already been proven that bolt fasteners based on the double thread mechanism have an excellent anti-loosening performance. The purpose of this study is to establish a mass production method for these double thread bolts (DTBs) by thread rolling. The pitch ratio of the coarse thread and the fine thread of the target DTB is set as 2 to 1. A two-die roller with a plunge feed is employed as the rolling method due to its fine processing precision. The roller dies used in the experiments have special grooves on the external surface which follow the same outline as the thread profiles of the DTB. Using these special dies, the DTB can be successfully formed in the same process as single thread bolts. The deformation of a workpiece during rolling is examined, and the examination shows that the formed material smoothly fills the die grooves in each cross section. The rolled DTBs completely pass the loosening test with extremely severe vibration and impact, as specified in NAS3354. The tensile fatigue strength of the rolled DTB is about 100% greater than that of the cutting DTB.

  2. Numerical simulation of the seismic behavior of self-centering steel beam-column connections with bottom flange friction devices

    NASA Astrophysics Data System (ADS)

    Guo, Tong; Song, Lianglong; Zhang, Guodong

    2011-06-01

    A new type of steel moment resisting frame with bottom flange friction devices (BFFDs) has been developed to provide self-centering capacity and energy dissipation, and to reduce permanent deformations under earthquakes. This paper presents a numerical simulation of self-centering beam-column connections with BFFDs, in which the gap opening /closing at the beam-column interfaces is simulated by using pairs of zero-length elements with compression-only material properties, and the energy dissipation due to friction is simulated by using truss elements with specified hysteretic behavior. In particular, the effect of the friction bolt bearing against the slotted plate in the BFFDs was modeled, so that the increase in lateral force and the loss of friction force due to the bolt bearing could be taken into account. Parallel elastic-perfectly plastic gap (ElasticPPGap) materials in the Open System for Earthquake Engineering Simulation (OpenSees) were used with predefined gaps to specify the sequence that each bolt went into the bearing and the corresponding increase in bending stiffness. The MinMax material in OpenSees is used to specify the minimum and maximum values of strains of the ElasticPPGap materials. To consider the loss of friction force due to bolt bearing, a number of parallel hysteretic materials were used, and the failure of these materials in sequence simulated the gradual loss of friction force. Analysis results obtained by using the proposed numerical model are discussed and compared with the test results under cyclic loadings and the seismic loading, respectively.

  3. The steel scrap age.

    PubMed

    Pauliuk, Stefan; Milford, Rachel L; Müller, Daniel B; Allwood, Julian M

    2013-04-01

    Steel production accounts for 25% of industrial carbon emissions. Long-term forecasts of steel demand and scrap supply are needed to develop strategies for how the steel industry could respond to industrialization and urbanization in the developing world while simultaneously reducing its environmental impact, and in particular, its carbon footprint. We developed a dynamic stock model to estimate future final demand for steel and the available scrap for 10 world regions. Based on evidence from developed countries, we assumed that per capita in-use stocks will saturate eventually. We determined the response of the entire steel cycle to stock saturation, in particular the future split between primary and secondary steel production. During the 21st century, steel demand may peak in the developed world, China, the Middle East, Latin America, and India. As China completes its industrialization, global primary steel production may peak between 2020 and 2030 and decline thereafter. We developed a capacity model to show how extensive trade of finished steel could prolong the lifetime of the Chinese steelmaking assets. Secondary steel production will more than double by 2050, and it may surpass primary production between 2050 and 2060: the late 21st century can become the steel scrap age.

  4. The steel scrap age.

    PubMed

    Pauliuk, Stefan; Milford, Rachel L; Müller, Daniel B; Allwood, Julian M

    2013-04-01

    Steel production accounts for 25% of industrial carbon emissions. Long-term forecasts of steel demand and scrap supply are needed to develop strategies for how the steel industry could respond to industrialization and urbanization in the developing world while simultaneously reducing its environmental impact, and in particular, its carbon footprint. We developed a dynamic stock model to estimate future final demand for steel and the available scrap for 10 world regions. Based on evidence from developed countries, we assumed that per capita in-use stocks will saturate eventually. We determined the response of the entire steel cycle to stock saturation, in particular the future split between primary and secondary steel production. During the 21st century, steel demand may peak in the developed world, China, the Middle East, Latin America, and India. As China completes its industrialization, global primary steel production may peak between 2020 and 2030 and decline thereafter. We developed a capacity model to show how extensive trade of finished steel could prolong the lifetime of the Chinese steelmaking assets. Secondary steel production will more than double by 2050, and it may surpass primary production between 2050 and 2060: the late 21st century can become the steel scrap age. PMID:23442209

  5. Analysis of Delamination Arrest Fasteners in Bolted-Bonded Composite Structures

    NASA Astrophysics Data System (ADS)

    Liu, Wenjing

    Delamination is one of the most critical damages in carbon fiber composites, which are being employed in primary aircraft structures. One common solution to prevent a delamination from propagating is to install fasteners, clamping the laminate together and partially arresting the delamination. In this thesis, the effectiveness of multiple fasteners installed in series to arrest the mixed-mode interlaminar failure in composite structures is investigated analytically. An accurate finite element model for predicting delamination propagation behavior of bolted-bonded structures was developed and validated by experimental test data. The finite element results showed that the presence of fasteners can slow down propagation of the crack by compressing the lamina together and transferring load via Mode II shear engagement of the fastener. Compared to the single-fastener case, damage tolerance of the structure was improved by the inclusion of the second fastener. Additionally, if the tensile modulus of the lamina is not high enough, laminate failure would occur before the delamination past the second fastener. Parametric studies were also performed to evaluate the influences of friction and laminate stiffness, fastener stiffness, fastener spacing and specimen width. Numerical results were discussed and a conclusion on the effectiveness of delamination arrest was drawn.

  6. Multi-field coupled sensing network for health monitoring of composite bolted joint

    NASA Astrophysics Data System (ADS)

    Wang, Yishou; Qing, Xinlin; Dong, Liang; Banerjee, Sourav

    2016-04-01

    Advanced fiber reinforced composite materials are becoming the main structural materials of next generation of aircraft because of their high strength and stiffness to weight ratios, and excellent designability. As key components of large composite structures, joints play important roles to ensure the integrity of the composite structures. However, it is very difficult to analyze the strength and failure modes of composite joints due to their complex nonlinear coupling factors. Therefore, there is a need to monitor, diagnose, evaluate and predict the structure state of composite joints. This paper proposes a multi-field coupled sensing network for health monitoring of composite bolted joints. Major work of this paper includes: 1) The concept of multifunctional sensor layer integrated with eddy current sensors, Rogowski coil and arrayed piezoelectric sensors; 2) Development of the process for integrating the eddy current sensor foil, Rogowski coil and piezoelectric sensor array in multifunctional sensor layer; 3) A new concept of smart composite joint with multifunctional sensing capability. The challenges for building such a structural state sensing system and some solutions to address the challenges are also discussed in the study.

  7. Application of viscous and Iwan modal damping models to experimental measurements from bolted structures

    DOE PAGES

    Deaner, Brandon J.; Allen, Matthew S.; Starr, Michael James; Segalman, Daniel J.; Sumali, Hartono

    2015-01-20

    Measurements are presented from a two-beam structure with several bolted interfaces in order to characterize the nonlinear damping introduced by the joints. The measurements (all at force levels below macroslip) reveal that each underlying mode of the structure is well approximated by a single degree-of-freedom (SDOF) system with a nonlinear mechanical joint. At low enough force levels, the measurements show dissipation that scales as the second power of the applied force, agreeing with theory for a linear viscously damped system. This is attributed to linear viscous behavior of the material and/or damping provided by the support structure. At larger forcemore » levels, the damping is observed to behave nonlinearly, suggesting that damping from the mechanical joints is dominant. A model is presented that captures these effects, consisting of a spring and viscous damping element in parallel with a four-parameter Iwan model. As a result, the parameters of this model are identified for each mode of the structure and comparisons suggest that the model captures the stiffness and damping accurately over a range of forcing levels.« less

  8. Application of viscous and Iwan modal damping models to experimental measurements from bolted structures

    SciTech Connect

    Deaner, Brandon J.; Allen, Matthew S.; Starr, Michael James; Segalman, Daniel J.; Sumali, Hartono

    2015-01-20

    Measurements are presented from a two-beam structure with several bolted interfaces in order to characterize the nonlinear damping introduced by the joints. The measurements (all at force levels below macroslip) reveal that each underlying mode of the structure is well approximated by a single degree-of-freedom (SDOF) system with a nonlinear mechanical joint. At low enough force levels, the measurements show dissipation that scales as the second power of the applied force, agreeing with theory for a linear viscously damped system. This is attributed to linear viscous behavior of the material and/or damping provided by the support structure. At larger force levels, the damping is observed to behave nonlinearly, suggesting that damping from the mechanical joints is dominant. A model is presented that captures these effects, consisting of a spring and viscous damping element in parallel with a four-parameter Iwan model. As a result, the parameters of this model are identified for each mode of the structure and comparisons suggest that the model captures the stiffness and damping accurately over a range of forcing levels.

  9. The Nuts and Bolts of Transcriptionally Silent Chromatin in Saccharomyces cerevisiae.

    PubMed

    Gartenberg, Marc R; Smith, Jeffrey S

    2016-08-01

    Transcriptional silencing in Saccharomyces cerevisiae occurs at several genomic sites including the silent mating-type loci, telomeres, and the ribosomal DNA (rDNA) tandem array. Epigenetic silencing at each of these domains is characterized by the absence of nearly all histone modifications, including most prominently the lack of histone H4 lysine 16 acetylation. In all cases, silencing requires Sir2, a highly-conserved NAD(+)-dependent histone deacetylase. At locations other than the rDNA, silencing also requires additional Sir proteins, Sir1, Sir3, and Sir4 that together form a repressive heterochromatin-like structure termed silent chromatin. The mechanisms of silent chromatin establishment, maintenance, and inheritance have been investigated extensively over the last 25 years, and these studies have revealed numerous paradigms for transcriptional repression, chromatin organization, and epigenetic gene regulation. Studies of Sir2-dependent silencing at the rDNA have also contributed to understanding the mechanisms for maintaining the stability of repetitive DNA and regulating replicative cell aging. The goal of this comprehensive review is to distill a wide array of biochemical, molecular genetic, cell biological, and genomics studies down to the "nuts and bolts" of silent chromatin and the processes that yield transcriptional silencing. PMID:27516616

  10. Effect of flange bolt preload on Space Shuttle main engine high pressure oxidizer turbopump housing analysis

    NASA Technical Reports Server (NTRS)

    Min, J. B.; Johnston, L. M.; Czekalski, B.

    1991-01-01

    Cracks at the seal fillet flange and the strut pilot groove of primary turbine drain passage of the space shuttle main engine (SSME) high pressure oxidizer turbopump (HPOTP) were observed and reported. Stress information for critical structural components in the SSME under actual conditions is necessary for design and life prediction analysis. However, little information is available about the stress distribution at this location under various combinations of loadings and environments. Thus, a stress analysis was conducted to determine an influence of the various operation and installation loads on the stresses of the HPOTP main mounting flange. To do this, a 3-D finite element model of the HPOTP housing was generated. A fairly comfortable margin of stresses at the flange fillet with respect to the yield stress of Inconel 718 is shown. However, it was revealed that the bending stress arising from the housing flange bolt preloads could significantly affect the stress distribution at the strut pilot groove of primary turbine drain passage in the HPOTP housing. Consequently, the information obtained from the present 3-D analysis results should be useful in guiding the development of the SSME HPOTP.

  11. Methods of forming steel

    DOEpatents

    Branagan, Daniel J.; Burch, Joseph V.

    2001-01-01

    In one aspect, the invention encompasses a method of forming a steel. A metallic glass is formed and at least a portion of the glass is converted to a crystalline steel material having a nanocrystalline scale grain size. In another aspect, the invention encompasses another method of forming a steel. A molten alloy is formed and cooled the alloy at a rate which forms a metallic glass. The metallic glass is devitrified to convert the glass to a crystalline steel material having a nanocrystalline scale grain size. In yet another aspect, the invention encompasses another method of forming a steel. A first metallic glass steel substrate is provided, and a molten alloy is formed over the first metallic glass steel substrate to heat and devitrify at least some of the underlying metallic glass of the substrate.

  12. Quantitative evaluation of residual torque of a loose bolt based on wave energy dissipation and vibro-acoustic modulation: A comparative study

    NASA Astrophysics Data System (ADS)

    Zhang, Zhen; Liu, Menglong; Su, Zhongqing; Xiao, Yi

    2016-11-01

    A wave energy dissipation (WED)-based linear acoustic approach and a vibro-acoustic modulation (VM)-based nonlinear method were developed comparatively, for detecting bolt loosening in bolted joints and subsequently evaluating the residual torque of the loose bolt. For WED-based, an analytical model residing on the Hertzian contact theory was established, whereby WED was linked to the residual torque of a loose bolt, contributing to a linear index. For VM-based, contact acoustic nonlinearity (CAN) engendered at the joining interface, when a pumping vibration perturbs a probing wave, was interrogated, and the nonlinear contact stiffness was described in terms of a Taylor series, on which basis a nonlinear index was constructed to associate spectral features with the residual torque. Based respectively on a linear and a nonlinear premise, the two indices were validated experimentally, and the results well coincided with theoretical predication. Quantitative comparison of the two indices surmises that the VM-based nonlinear method outperforms the WED-based linear approach in terms of sensitivity and accuracy, and particularly when the bolt loosening is in its embryo stage. In addition, the detectability of the nonlinear index is not restricted by the type of the joint, against a high dependence of its linear counterpart on the joint type.

  13. Automated detection of cracks on the faying surface within high-load transfer bolted speciments

    NASA Astrophysics Data System (ADS)

    Wheatley, Gregory; Kollgaard, Jeffrey R.

    2003-07-01

    Boeing is currently conducting evaluation testing of the Comparative Vacuum Monitoring (CVMTM) system offered by Structural Monitoring Systems, Ltd (SMS). Initial testing has been conducted by SMS, with further test lab validations to be performed at Boeing in Seattle. Testing has been conducted on dog bone type specimens that have been cut at the center line. A notch was cut at one of the bolt holes and a CVM sensor installed on both sides of the plate. The doublers were added and a single line of 4 bolts along the longitudinal center line were used to attach the doubler plates to the dog bone type specimen. In this way, a high load transfer situation exists between the two halves of the dog bone specimen and the doubler plates. The CVM sensors are slightly over 0.004" (0.1mm) in thickness and are installed directly upon the faying surface of the dog bone specimen. Testing was conducted on an Instron 8501 Servohydraulic testing machine at the Department of Mechanical and Materials Engineering, University of Western Australia. The standard laboratory equipment offered by Structural Monitoring Systems, Ltd was used for crack detection. This equipment included the Kvac (vacuum supply) and the Sim8 (flow meter). The Sim8 was electrically connected to the Instron machine so that as soon as a crack was detected, fatigue loading was halted. The aim of the experiment was for CVM to detect a crack on the faying surface of the specimens at a length of 0.050" +/- 0.010". This was accomplished successfully. CVM has been developed on the principle that a small volume maintained at a low vacuum is extremely sensitive to any ingress of air. In addition to the load bearing sensors described above, self-adhesive, elastomeric sensors with fine channels on the adhesive face have been developed. When the sensors have been adhered to the structure under test, these fine channels, and the structure itself, form a manifold of galleries alternately at low vacuum and atmospheric pressure

  14. In Situ Measurement and Prediction of Stresses and Strains During Casting of Steel

    NASA Astrophysics Data System (ADS)

    Galles, Daniel; Beckermann, Christoph

    2016-02-01

    Modeling the thermo-mechanical behavior of steel during casting is of great importance for the prediction of distortions and cracks. In this study, an elasto-visco-plastic constitutive law is calibrated with mechanical measurements from casting experiments. A steel bar is solidified in a sand mold and strained by applying a force to bolts that are embedded in the two ends of the bar. The temporal evolutions of the restraint force and the bar's length change are measured in situ. The experiments are simulated by inputting calculated transient temperature fields into a finite element stress analysis that employs the measured forces as boundary conditions. The thermal strain predictions are validated using data from experiments without a restraint. Initial estimates of the constitutive model parameters are obtained from available mechanical test data involving reheated steel specimens. The temperature dependence of the strain rate sensitivity exponent is then adjusted until the measured and predicted length changes of the strained bars agree. The resulting calibrated mechanical property dataset is valid for the high-temperature austenite phase of steel. The data reveal a significantly different mechanical behavior during casting compared to what the stress-strain data from reheated specimens show.

  15. A guide for the ASME code for austenitic stainless steel containment vessels for high-level radioactive materials

    SciTech Connect

    Raske, D.T.

    1995-06-01

    The design and fabrication criteria recommended by the US Department of Energy (DOE) for high-level radioactive materials containment vessels used in packaging is found in Section III, Division 1, Subsection NB of the ASME Boiler and Pressure Vessel Code. This Code provides material, design, fabrication, examination, and testing specifications for nuclear power plant components. However, many of the requirements listed in the Code are not applicable to containment vessels made from austenitic stainless steel with austenitic or ferritic steel bolting. Most packaging designers, engineers, and fabricators are intimidated by the sheer volume of requirements contained in the Code; consequently, the Code is not always followed and many requirements that do apply are often overlooked during preparation of the Safety Analysis Report for Packaging (SARP) that constitutes the basis to evaluate the packaging for certification.

  16. Regulation of bolting and identification of the α-tubulin gene family in Brassica rapa L. ssp pekinensis.

    PubMed

    Zhang, Y W; Jin, D; Xu, C; Zhang, L; Guo, M H; Fang, Z Y

    2016-01-01

    Microtubules are important components of eukaryotic cells, and they play vital roles in cell morphogenesis, carrying of signaling molecules, transport of materials, and establishing the cell polarity. During bolting of biennial plants, cell division and elongation are involved, and cell elongation inevitably involves the microtubules arrangement and expression of related genes. So we deduce that it is of great significance to figure out the mechanism of bolting and flowering in which TUA genes are involved. In the present study, bioinformatic methods were used to predict and identify the α-tubulin gene family (BrTUAs) in Brassica rapa L. ssp pekinensis (Chinese cabbage) through the alignment of AtTUA gene sequence from Arabidopsis thaliana with the B. rapa genome database (http://brassicadb.org/brad/) using the basic local alignment search tool. The change in the structure and functions of BrTUAs during the process of evolution, cis-acting elements in the promoter sequences of BrTUAs, and the expression of the identified genes was also analyzed. Twelve members of the α-tubulin gene family were identified from Chinese cabbage. The gene length, intron, exon, and promoter regions were determined to have changed significantly during the genome evolution. Only five of the 12 members were encoded completely and were observed to differ in their spatial and temporal expression. The five BrTUA promoter sequences contained different numbers of cis-elements responsive to light and low-temperature response, cis-elements responsive among which hormonal responses were significantly different. We also report that the BrTUAs were involved in the regulation of the bolting in Chinese cabbage, and propose that this process could be controlled by regulating the expression of BrTUAs.

  17. Regulation of bolting and identification of the α-tubulin gene family in Brassica rapa L. ssp pekinensis.

    PubMed

    Zhang, Y W; Jin, D; Xu, C; Zhang, L; Guo, M H; Fang, Z Y

    2016-01-01

    Microtubules are important components of eukaryotic cells, and they play vital roles in cell morphogenesis, carrying of signaling molecules, transport of materials, and establishing the cell polarity. During bolting of biennial plants, cell division and elongation are involved, and cell elongation inevitably involves the microtubules arrangement and expression of related genes. So we deduce that it is of great significance to figure out the mechanism of bolting and flowering in which TUA genes are involved. In the present study, bioinformatic methods were used to predict and identify the α-tubulin gene family (BrTUAs) in Brassica rapa L. ssp pekinensis (Chinese cabbage) through the alignment of AtTUA gene sequence from Arabidopsis thaliana with the B. rapa genome database (http://brassicadb.org/brad/) using the basic local alignment search tool. The change in the structure and functions of BrTUAs during the process of evolution, cis-acting elements in the promoter sequences of BrTUAs, and the expression of the identified genes was also analyzed. Twelve members of the α-tubulin gene family were identified from Chinese cabbage. The gene length, intron, exon, and promoter regions were determined to have changed significantly during the genome evolution. Only five of the 12 members were encoded completely and were observed to differ in their spatial and temporal expression. The five BrTUA promoter sequences contained different numbers of cis-elements responsive to light and low-temperature response, cis-elements responsive among which hormonal responses were significantly different. We also report that the BrTUAs were involved in the regulation of the bolting in Chinese cabbage, and propose that this process could be controlled by regulating the expression of BrTUAs. PMID:26909938

  18. Stress-corrosion cracking and surface-pitting tests of NiCrFe alloy bolts (LWBR development program)

    SciTech Connect

    Keller, K.L.

    1983-02-01

    Accelerated corrosion tests confirmed the adequate resistance to stress corrosion cracking (SCC) of the specific heats of NiCrFe X-750 and NiCrFe 600 used as bolts in the LWBR. SCC acceleration was achieved by running autoclave corrosion tests at 680/sup 0/F (well above the LWBR core operating temperatures of approximately 525/sup 0/F to 560/sup 0/F). Component stress levels were representative of maximum service stresses. No specimens from heats of either alloy suffered SCC.

  19. Effect of tree species and end seal on attractiveness and utility of cut bolts to the redbay ambrosia beetle and granulate ambrosia beetle (coleoptera: Curculionidae: Scolytinae).

    PubMed

    Mayfield, A E; Hanula, J L

    2012-04-01

    The redbay ambrosia beetle, Xyleborus glabratus Eichhoff, is a non-native invasive pest and vector of the fungus that causes laurel wilt disease in certain trees of the family Lauraceae. This study assessed the relative attractiveness and suitability of cut bolts of several tree species to X. glabratus. In 2009, female X. glabratus were equally attracted to traps baited with swampbay (Persea palustris (Rafinesque) Sargent) and camphortree (Cinnamomum camphora (L.) J. Presl), which were more attractive than avocado (Persea americana Miller), lancewood (Ocotea coriacea (Swartz) Britton), and sweetbay (Magnolia virginiana L.). These species were more attractive than loblolly bay (Gordonia lasianthus (L.) J. Ellis). X. glabratus entrance hole density and emergence from caged bolts were highest on swampbay and camphortree. In 2010, swampbay was significantly more attractive to X. glabratus than sassafras (Sassafras albidum (Nuttall) Nees), yellow poplar (Liriodendron tulipifera L.), and eastern redbud (Cercis canadensis L.). Sassafras bolts end sealed with a liquid wax-and-water emulsion were more attractive to X. glabratus than end-sealed bolts of yellow poplar and redbud. Relative to unsealed bolts, end seal decreased X. glabratus entrance hole density on swampbay and decreased granulate ambrosia beetle (Xylosandrus crassiusculus (Motschulsky)) trap catch, entrance hole density, and adult emergence from swampbay. X. crassiusculus was not attracted to sassafras, yellow poplar, and redbud and was not more attracted to manuka oil than to unbaited traps. Sassafras was more attractive to X. glabratus than previously reported and supported reproducing populations of the insect. End sealing bolts with a wax-and-water emulsion may not be optimal for attracting and rearing ambrosia beetles in small logs.

  20. Induction of early bolting in Arabidopsis thaliana by triacontanol, cerium and lanthanum is correlated with increased endogenous concentration of isopentenyl adenosine (iPAdos).

    PubMed

    He, Ya-Wen; Loh, Chiang-Shiong

    2002-03-01

    The effects of triacontanol (TRIA), applied singly or in combination with cerium nitrate and lanthanum nitrate, on bolting of Arabidopsis thaliana were studied. Triacontanol (0.1 to 0.6 microM) added to the culture medium induced early bolting. TRIA (0.3 microM) applied with low concentrations of cerium and lanthanum caused a synergistic stimulation of bolting. In medium containing 0.3 microM TRIA, 0.1 microM cerium nitrate and 0.1 mM lanthanum nitrate, 82% of the plants bolted 20 d after seed sowing compared to only 8.6% in basal medium and 47.8% in medium with TRIA only. The changes in the endogenous concentrations of total cytokinins of the isopentenyl adenine (IP) subfamily in the leaf and root tissues were correlated with TRIA-induced early bolting. The combined treatment of TRIA (0.3 microM), cerium nitrate (0.1 microM) and lanthanum nitrate (0.1 mM) resulted in a significant increase in the endogenous concentrations of total cytokinins of the IP subfamily in the root and leaf tissues compared to plants growing in the basal medium and medium with TRIA. The exogenous application of six natural cytokinins to the plants revealed that only isopentenyl adenosine (iPAdos) was as effective as TRIA on floral bud formation. iPAdos was also found to have similar effects as TRIA on root growth and reproductive growth. These results suggest a correlation between the early bolting induced by TRIA, cerium and lanthanum and the production of higher concentrations of endogenous iPAdos.

  1. Effect of CO2 enrichment on the glucosinolate contents under different nitrogen levels in bolting stem of Chinese kale (Brassica alboglabra L.).

    PubMed

    La, Gui-xiao; Fang, Ping; Teng, Yi-bo; Li, Ya-juan; Lin, Xian-yong

    2009-06-01

    The effects of CO(2) enrichment on the growth and glucosinolate (GS) concentrations in the bolting stem of Chinese kale (Brassica alboglabra L.) treated with three nitrogen (N) concentrations (5, 10, and 20 mmol/L) were investigated. Height, stem thickness, and dry weights of the total aerial parts, bolting stems, and roots, as well as the root to shoot ratio, significantly increased as CO(2) concentration was elevated from 350 to 800 microl/L at each N concentration. In the edible part of the bolting stem, 11 individual GSs were identified, including 7 aliphatic and 4 indolyl GSs. GS concentration was affected by the elevated CO(2) concentration, N concentration, and CO(2)xN interaction. At 5 and 10 mmol N/L, the concentrations of aliphatic GSs and total GSs significantly increased, whereas those of indolyl GSs were not affected, by elevated atmospheric CO(2). However, at 20 mmol N/L, elevated CO(2) had no significant effects on the concentrations of total GSs and total indolyl GSs, but the concentrations of total aliphatic GSs significantly increased. Moreover, the bolting stem carbon (C) content increased, whereas the N and sulfur (S) contents decreased under elevated CO(2) concentration in the three N treatments, resulting in changes in the C/N and N/S ratios. Also the C/N ratio is not a reliable predictor of change of GS concentration, while the changes in N and S contents and the N/S ratio at the elevated CO(2) concentration may influence the GS concentration in Chinese kale bolting stems. The results demonstrate that high nitrogen supply is beneficial for the growth of Chinese kale, but not for the GS concentration in bolting stems, under elevated CO(2) condition.

  2. Modern Steel Framed Schools.

    ERIC Educational Resources Information Center

    American Inst. of Steel Construction, Inc., New York, NY.

    In view of the cost of structural framing for school buildings, ten steel-framed schools are examined to review the economical advantages of steel for school construction. These schools do not resemble each other in size, shape, arrangement or unit cost; some are original in concept and architecture, and others are conservative. Cost and…

  3. Steel Industry Wastes.

    ERIC Educational Resources Information Center

    Schmidtke, N. W.; Averill, D. W.

    1978-01-01

    Presents a literature review of wastes from steel industry, covering publications of 1976-77. This review covers: (1) coke production; (2) iron and steel production; (3) rolling operations; and (4) surface treatment. A list of 133 references is also presented. (NM)

  4. The Steel Band.

    ERIC Educational Resources Information Center

    Weil, Bruce

    1996-01-01

    Describes studying the steel drum, an import from Trinidad, as an instrument of intellectual growth. Describes how developing a steel drum band provided Montessori middle school students the opportunity to experience some important feelings necessary to emotional growth during this difficult age: competence, usefulness, independence, and…

  5. A structural health monitoring fastener for tracking fatigue crack growth in bolted metallic joints

    NASA Astrophysics Data System (ADS)

    Rakow, Alexi Schroder

    sensor, data acquisition hardware, algorithm, and diagnostic display. The AIME sensor design, SHM Fastener, and complete SHM system are presented along with experimental results from a series of single-layer and bolted double lap joint aluminum laboratory specimens to validate the capability of these sensors to monitor metallic joints for fastener hole cracks. Fatigue cracks were successfully tracked to over 0.7 inches from the fastener hole in these tests. Sensor output obtained from single-layer fatigue specimens was compared with analytical predictions for fatigue crack growth versus cycle number showing a good correlation in trend between sensor output and predicted crack size.

  6. EAST ELEVATION, LTV STEEL (FORMERLY REPUBLIC STEEL), 8" BAR MILL, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    EAST ELEVATION, LTV STEEL (FORMERLY REPUBLIC STEEL), 8" BAR MILL, BUFFALO PLANT. VIEW LOOKING SOUTHWEST FROM ROLL SHOP. 8" BAR MILL DESIGNED AND BUILT BY DONNER STEEL CO. (PREDECESSOR OF REPUBLIC), 1919-1920. FOR DESCRIPTION OF ORIGINAL MILL SEE "IRON AGE", 116\\4 (23 JULY 1925): 201-204. - LTV Steel, 8-inch Bar Mill, Buffalo Plant, Buffalo, Erie County, NY

  7. Structural health monitoring for bolt loosening via a non-invasive vibro-haptics human-machine cooperative interface

    NASA Astrophysics Data System (ADS)

    Pekedis, Mahmut; Mascerañas, David; Turan, Gursoy; Ercan, Emre; Farrar, Charles R.; Yildiz, Hasan

    2015-08-01

    For the last two decades, developments in damage detection algorithms have greatly increased the potential for autonomous decisions about structural health. However, we are still struggling to build autonomous tools that can match the ability of a human to detect and localize the quantity of damage in structures. Therefore, there is a growing interest in merging the computational and cognitive concepts to improve the solution of structural health monitoring (SHM). The main object of this research is to apply the human-machine cooperative approach on a tower structure to detect damage. The cooperation approach includes haptic tools to create an appropriate collaboration between SHM sensor networks, statistical compression techniques and humans. Damage simulation in the structure is conducted by releasing some of the bolt loads. Accelerometers are bonded to various locations of the tower members to acquire the dynamic response of the structure. The obtained accelerometer results are encoded in three different ways to represent them as a haptic stimulus for the human subjects. Then, the participants are subjected to each of these stimuli to detect the bolt loosened damage in the tower. Results obtained from the human-machine cooperation demonstrate that the human subjects were able to recognize the damage with an accuracy of 88 ± 20.21% and response time of 5.87 ± 2.33 s. As a result, it is concluded that the currently developed human-machine cooperation SHM may provide a useful framework to interact with abstract entities such as data from a sensor network.

  8. Magnetic resonance imaging and computer tomography of brain lesions in water buffaloes and cattle stunned with handguns or captive bolts.

    PubMed

    Schwenk, Barbara K; Lechner, Isabel; Ross, Steffen G; Gascho, Dominic; Kneubuehl, Beat P; Glardon, Matthieu; Stoffel, Michael H

    2016-03-01

    Owing to the demand for genuine mozzarella, some 330 water buffaloes are being slaughtered every year in Switzerland albeit a stunning procedure meeting animal welfare and occupational safety requirements remains to be established. To provide a basis for improvements, we sized anatomical specifics in water buffaloes and cattle and we assessed brain lesions after stunning with captive bolts or handguns by diagnostic imaging. In water buffaloes and cattle, the median distance from the frontal skin surface to the inner bone table was 74.0mm (56.0-100.0mm) vs 36.6mm (29.3-44.3mm) and from skin to the thalamus 144.8mm (117.1-172.0mm) vs 102.0 (101.0-121.0mm), respectively. Consequently, customary captive bolt stunners may be inadequate. Free bullets are potentially suitable for stunning buffaloes but involve occupational safety hazards. The results of the present study shall be used to develop a device allowing effective and safe stunning of water buffaloes.

  9. Magnetic resonance imaging and computer tomography of brain lesions in water buffaloes and cattle stunned with handguns or captive bolts.

    PubMed

    Schwenk, Barbara K; Lechner, Isabel; Ross, Steffen G; Gascho, Dominic; Kneubuehl, Beat P; Glardon, Matthieu; Stoffel, Michael H

    2016-03-01

    Owing to the demand for genuine mozzarella, some 330 water buffaloes are being slaughtered every year in Switzerland albeit a stunning procedure meeting animal welfare and occupational safety requirements remains to be established. To provide a basis for improvements, we sized anatomical specifics in water buffaloes and cattle and we assessed brain lesions after stunning with captive bolts or handguns by diagnostic imaging. In water buffaloes and cattle, the median distance from the frontal skin surface to the inner bone table was 74.0mm (56.0-100.0mm) vs 36.6mm (29.3-44.3mm) and from skin to the thalamus 144.8mm (117.1-172.0mm) vs 102.0 (101.0-121.0mm), respectively. Consequently, customary captive bolt stunners may be inadequate. Free bullets are potentially suitable for stunning buffaloes but involve occupational safety hazards. The results of the present study shall be used to develop a device allowing effective and safe stunning of water buffaloes. PMID:26610289

  10. Nuclear transmutation in steels

    NASA Astrophysics Data System (ADS)

    Belozerova, A. R.; Shimanskii, G. A.; Belozerov, S. V.

    2009-05-01

    The investigations of the effects of nuclear transmutation in steels that are widely used in nuclear power and research reactors and in steels that are planned for the application in thermonuclear fusion plants, which are employed under the conditions of a prolonged action of neutron irradiation with different spectra, made it possible to study the effects of changes in the isotopic and chemical composition on the tendency of changes in the structural stability of these steels. For the computations of nuclear transmutation in steels, we used a program complex we have previously developed on the basis of algorithms for constructing branched block-type diagrams of nuclide transformations and for locally and globally optimizing these diagrams with the purpose of minimizing systematic errors in the calculation of nuclear transmutation. The dependences obtained were applied onto a Schaeffler diagram for steels used for structural elements of reactors. For the irradiation in fission reactors, we observed only a weak influence of the effects of nuclear transmutation in steels on their structural stability. On the contrary, in the case of irradiation with fusion neutrons, a strong influence of the effects of nuclear transmutation in steels on their structural stability has been noted.

  11. Seismic Performance Evaluation of Steel Moment Resisting Frames with WUF-B Connections

    SciTech Connect

    Moon, Ki-Hoon; Han, Sang-Whan

    2008-07-08

    The purpose of this study is to evaluate the seismic performance of the moment resisting steel frames having Welded Unreinforced Flange-Bolted web (WUF-B) connections. The connections are designed and detailed in compliance with FEMA 350 recommended seismic design criteria. To conduct the seismic performance evaluation this study developed an analytical model for the pre- and post-Northridge connections based on test results. Three different frames are considered which have three-, nine- and twenty-story. Incremental Dynamic Analysis (IDA is conducted to estimate limit state capacities The performance of the frames having either pre- or post-Northridge connections is compared with the corresponding frame with ductile connections which do not experience connection fracture. The analytical results showed that buildings with post-Northridge WUF-B connections provide superior strength and interstory drift ratio capacity than buildings with pre-Northridge WUF-B connections.

  12. Glass Stronger than Steel

    DOE R&D Accomplishments Database

    Yarris, Lynn

    2011-03-28

    A new type of damage-tolerant metallic glass, demonstrating a strength and toughness beyond that of steel or any other known material, has been developed and tested by a collaboration of researchers from Berkeley Lab and Caltech.

  13. Structural Amorphous Steels

    NASA Astrophysics Data System (ADS)

    Lu, Z. P.; Liu, C. T.; Thompson, J. R.; Porter, W. D.

    2004-06-01

    Recent advancement in bulk metallic glasses, whose properties are usually superior to their crystalline counterparts, has stimulated great interest in fabricating bulk amorphous steels. While a great deal of effort has been devoted to this field, the fabrication of structural amorphous steels with large cross sections has remained an alchemist’s dream because of the limited glass-forming ability (GFA) of these materials. Here we report the discovery of structural amorphous steels that can be cast into glasses with large cross-section sizes using conventional drop-casting methods. These new steels showed interesting physical, magnetic, and mechanical properties, along with high thermal stability. The underlying mechanisms for the superior GFA of these materials are discussed.

  14. Ultrasonic butt welding of aluminum, aluminum alloy and stainless steel plate specimens.

    PubMed

    Tsujino, Jiromaru; Hidai, Kazuaki; Hasegawa, Atsushi; Kanai, Ryoichi; Matsuura, Hisanori; Matsushima, Kaoru; Ueoka, Tetsugi

    2002-05-01

    Welding characteristics of aluminum, aluminum alloy and stainless steel plate specimens of 6.0 mm thickness by a 15 kHz ultrasonic butt welding system were studied. There are no detailed welding condition data of these specimens although the joining of these materials are required due to anticorrosive and high strength characteristics for not only large specimens but small electronic parts especially. These specimens of 6.0 mm thickness were welded end to end using a 15 kHz ultrasonic butt welding equipment with a vibration source using eight bolt-clamped Langevin type PZT transducers and a 50 kW static induction thyristor power amplifier. The stainless steel plate specimens electrolytically polished were joined with welding strength almost equal to the material strength under rather large vibration amplitude of 25 microm (peak-to-zero value), static pressure 70 MPa and welding time of 1.0-3.0 s. The hardness of stainless steel specimen adjacent to a welding surface increased about 20% by ultrasonic vibration.

  15. Guided ultrasonic waves for non-destructive monitoring of the stress levels in prestressed steel strands.

    PubMed

    Chaki, S; Bourse, G

    2009-02-01

    The safety of prestressed civil structures such as bridges, dams, nuclear power plants, etc. directly involves the security of both environment and users. Health monitoring of the tensioning components, such as strands, tendons, bars, anchorage bolts, etc. is an important research topic and a challenging task bringing together the non-destructive evaluation (NDE) and civil engineering communities. This paper deals with a guided ultrasonic wave procedure for monitoring the stress levels in seven-wire steel strands (15.7 mm in diameter). The mechanical and geometrical characteristics of the prestressed strands were taken into account for optimizing the measurement configuration and then the choice of the guided ultrasonic mode at a suitable frequency. Simplified acoustoelastic formulations were derived from the acoustoelasticity theory according to either calibration test or in situ measurement. The results from acoustoelastic measurements on the seven-wire steel strands are presented and discussed in the case of calibration tests and industrially prestressed strands. They show the potential and the suitability of the proposed guided wave method for evaluating the stress levels in the tested seven-wire steel strands. PMID:18804832

  16. Life after Steel

    ERIC Educational Resources Information Center

    Mangan, Katherine

    2013-01-01

    Bobby Curran grew up in a working-class neighborhood in Baltimore, finished high school, and followed his grandfather's steel-toed bootprints straight to Sparrows Point, a 3,000-acre sprawl of industry on the Chesapeake Bay. College was not part of the plan. A gritty but well-paying job at the RG Steel plant was Mr. Curran's ticket to a secure…

  17. Waste product profile: Steel cans

    SciTech Connect

    Miller, C.

    1996-07-01

    Steel cans are made from tinplate steel, which is produced in basic oxygen furnaces. A thin layer of tin is applied to the can`s inner and outer surfaces to prevent rusting and protect food and beverage flavors. As a result, steel cans are often called tin cans. Steel mills are the largest market for steel cans. Integrated mills use the basic oxygen process to manufacture tinplate, appliances, car bodies, and steel framing. Electric arc furnaces use 100% scrap to produce steel shapes such as railroad ties and bridge spans. Electric arc furnaces are more geographically diverse and tend to have smaller capacities than basic oxygen furnaces. Detinners remove the tin from steel cans for resale to tin using industries. Continued decreases in the amount of tin used in steel cans has lessened the importance of this market. Foundries use scrap as a raw material in making castings and molds for industrial users.

  18. Articles comprising ferritic stainless steels

    DOEpatents

    Rakowski, James M.

    2016-06-28

    An article of manufacture comprises a ferritic stainless steel that includes a near-surface region depleted of silicon relative to a remainder of the ferritic stainless steel. The article has a reduced tendency to form an electrically resistive silica layer including silicon derived from the steel when the article is subjected to high temperature oxidizing conditions. The ferritic stainless steel is selected from the group comprising AISI Type 430 stainless steel, AISI Type 439 stainless steel, AISI Type 441 stainless steel, AISI Type 444 stainless steel, and E-BRITE.RTM. alloy, also known as UNS 44627 stainless steel. In certain embodiments, the article of manufacture is a fuel cell interconnect for a solid oxide fuel cell.

  19. Ultraprecision XY stage using a hybrid bolt-clamped Langevin-type ultrasonic linear motor for continuous motion

    NASA Astrophysics Data System (ADS)

    Lee, Dong-Jin; Lee, Sun-Kyu

    2015-01-01

    This paper presents a design and control system for an XY stage driven by an ultrasonic linear motor. In this study, a hybrid bolt-clamped Langevin-type ultrasonic linear motor was manufactured and then operated at the resonance frequency of the third longitudinal and the sixth lateral modes. These two modes were matched through the preload adjustment and precisely tuned by the frequency matching method based on the impedance matching method with consideration of the different moving weights. The XY stage was evaluated in terms of position and circular motion. To achieve both fine and stable motion, the controller consisted of a nominal characteristics trajectory following (NCTF) control for continuous motion, dead zone compensation, and a switching controller based on the different NCTFs for the macro- and micro-dynamics regimes. The experimental results showed that the developed stage enables positioning and continuous motion with nanometer-level accuracy.

  20. Ultraprecision XY stage using a hybrid bolt-clamped Langevin-type ultrasonic linear motor for continuous motion.

    PubMed

    Lee, Dong-Jin; Lee, Sun-Kyu

    2015-01-01

    This paper presents a design and control system for an XY stage driven by an ultrasonic linear motor. In this study, a hybrid bolt-clamped Langevin-type ultrasonic linear motor was manufactured and then operated at the resonance frequency of the third longitudinal and the sixth lateral modes. These two modes were matched through the preload adjustment and precisely tuned by the frequency matching method based on the impedance matching method with consideration of the different moving weights. The XY stage was evaluated in terms of position and circular motion. To achieve both fine and stable motion, the controller consisted of a nominal characteristics trajectory following (NCTF) control for continuous motion, dead zone compensation, and a switching controller based on the different NCTFs for the macro- and micro-dynamics regimes. The experimental results showed that the developed stage enables positioning and continuous motion with nanometer-level accuracy.

  1. An Application of Retroduction to Analyzing and Testing the Backing off of Nuts and Bolts During Dynamic Loading

    NASA Technical Reports Server (NTRS)

    Kerley, James J.

    1987-01-01

    The method of retroduction, adapted from the doctoral thesis of Dr. A. Croce, relies on a process of dialectic questioning that begins with the information sought, proceeds to Given items (either in the form of dimensions or limits of research). and to Known mathematical forms of analysis in design or to principles of study in research. Finally, analysis and synthesis are used to abstract the dielectic questions and to arrive at the information desired. This method is used to solve the engineering design problem of a beam and to determine why bolts and nuts vibrate apart. Both mathematical analysis and dialectic logical analysis are utilized. Results are provided of tests conducted to check the retroductive study of why and how nuts back off.

  2. Ultraprecision XY stage using a hybrid bolt-clamped Langevin-type ultrasonic linear motor for continuous motion

    SciTech Connect

    Lee, Dong-Jin; Lee, Sun-Kyu

    2015-01-15

    This paper presents a design and control system for an XY stage driven by an ultrasonic linear motor. In this study, a hybrid bolt-clamped Langevin-type ultrasonic linear motor was manufactured and then operated at the resonance frequency of the third longitudinal and the sixth lateral modes. These two modes were matched through the preload adjustment and precisely tuned by the frequency matching method based on the impedance matching method with consideration of the different moving weights. The XY stage was evaluated in terms of position and circular motion. To achieve both fine and stable motion, the controller consisted of a nominal characteristics trajectory following (NCTF) control for continuous motion, dead zone compensation, and a switching controller based on the different NCTFs for the macro- and micro-dynamics regimes. The experimental results showed that the developed stage enables positioning and continuous motion with nanometer-level accuracy.

  3. Profiles in garbage: Steel cans

    SciTech Connect

    Miller, C.

    1998-02-01

    Steel mills are the largest market for steel cans. Integrated mills use the basic oxygen process to manufacture tinplate, appliances, car bodies, and steel framing. Electric arc furnaces use 100% scrap to produce steel shapes such as railroad ties and bridge spans. Electric arc furnaces are more geographically diverse and tend to have smaller capacities than basic oxygen furnaces. Detinners remove the tin from steel cans for resale to tin using industries. With less tin use in steel cans, the importance of the detinning market has declined substantially. Foundries use scrap as a raw material in making castings and molds for industrial users.

  4. Evaluation of Stress Corrosion Cracking Susceptibility Using Fracture Mechanics Techniques, Part 1. [environmental tests of aluminum alloys, stainless steels, and titanium alloys

    NASA Technical Reports Server (NTRS)

    Sprowls, D. O.; Shumaker, M. B.; Walsh, J. D.; Coursen, J. W.

    1973-01-01

    Stress corrosion cracking (SSC) tests were performed on 13 aluminum alloys, 13 precipitation hardening stainless steels, and two titanium 6Al-4V alloy forgings to compare fracture mechanics techniques with the conventional smooth specimen procedures. Commercially fabricated plate and rolled or forged bars 2 to 2.5-in. thick were tested. Exposures were conducted outdoors in a seacoast atmosphere and in an inland industrial atmosphere to relate the accelerated tests with service type environments. With the fracture mechanics technique tests were made chiefly on bolt loaded fatigue precracked compact tension specimens of the type used for plane-strain fracture toughness tests. Additional tests of the aluminum alloy were performed on ring loaded compact tension specimens and on bolt loaded double cantilever beams. For the smooth specimen procedure 0.125-in. dia. tensile specimens were loaded axially in constant deformation type frames. For both aluminum and steel alloys comparative SCC growth rates obtained from tests of precracked specimens provide an additional useful characterization of the SCC behavior of an alloy.

  5. View northwest, wharf A, sheet steel bulkhead, steel lift tower ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View northwest, wharf A, sheet steel bulkhead, steel lift tower - U.S. Coast Guard Sandy Hook Station, Western Docking Structure, West of intersection of Canfield Road & Hartshorne Drive, Highlands, Monmouth County, NJ

  6. Superclean steel development

    SciTech Connect

    Richman, R.H.; McNaughton, W.P. )

    1989-12-01

    The Electric Power Research Institute has actively encouraged and sponsored a number of research projects to develop a superclean 3.5NiCrMoV steel for low pressure turbine rotors. Such steel is highly resistant to temper embrittlement and will thus facilitate increased efficiency in electricity generation through the use of higher operating temperatures and improvements in design. The objective of this interim report was to integrate the results that have been generated to date worldwide in the pursuit of superclean steel. The report contains detailed findings that enable the interested utility to evaluate how the results affect utility decision making. A companion document has been written to summarize the findings from this technical report. The results indicate that steels with impurity contents typical of the superclean specification can be manufactured for production rotors with properties that equal or exceed those for conventional 3.5NiCrMoV rotors in every detail. Of particular interest are the results that the superclean steels appear to be virtually resistant to temper embrittlement to a temperature of 500 {degrees}C. 109 refs., 51 figs., 9 tabs.

  7. Brazing titanium to stainless steel

    NASA Technical Reports Server (NTRS)

    Batista, R. I.

    1980-01-01

    Titanium and stainless-steel members are usually joined mechanically for lack of any other effective method. New approach using different brazing alloy and plating steel member with nickel resolves problem. Process must be carried out in inert atmosphere.

  8. Continuous steel production and apparatus

    DOEpatents

    Peaslee, Kent D.; Peter, Jorg J.; Robertson, David G. C.; Thomas, Brian G.; Zhang, Lifeng

    2009-11-17

    A process for continuous refining of steel via multiple distinct reaction vessels for melting, oxidation, reduction, and refining for delivery of steel continuously to, for example, a tundish of a continuous caster system, and associated apparatus.

  9. A-3 steel work completed

    NASA Technical Reports Server (NTRS)

    2009-01-01

    Stennis Space Center engineers celebrated a key milestone in construction of the A-3 Test Stand on April 9 - completion of structural steel work. Workers with Lafayette (La.) Steel Erector Inc. placed the last structural steel beam atop the stand during a noon ceremony attended by more than 100 workers and guests.

  10. Microbial-Influenced Corrosion of Corten Steel Compared with Carbon Steel and Stainless Steel in Oily Wastewater by Pseudomonas aeruginosa

    NASA Astrophysics Data System (ADS)

    Mansouri, Hamidreza; Alavi, Seyed Abolhasan; Fotovat, Meysam

    2015-07-01

    The microbial corrosion behavior of three important steels (carbon steel, stainless steel, and Corten steel) was investigated in semi petroleum medium. This work was done in modified nutrient broth (2 g nutrient broth in 1 L oily wastewater) in the presence of Pseudomonas aeruginosa and mixed culture (as a biotic media) and an abiotic medium for 2 weeks. The behavior of corrosion was analyzed by spectrophotometric and electrochemical methods and at the end was confirmed by scanning electron microscopy. The results show that the degree of corrosion of Corten steel in mixed culture, unlike carbon steel and stainless steel, is less than P. aeruginosa inoculated medium because some bacteria affect Corten steel less than other steels. According to the experiments, carbon steel had less resistance than Corten steel and stainless steel. Furthermore, biofilm inhibits separated particles of those steels to spread to the medium; in other words, particles get trapped between biofilm and steel.

  11. Torque vs. induced load of A-286, and MP35N nuts and bolts with cadmium, dry film, and cetyl alcohol lubricants

    NASA Technical Reports Server (NTRS)

    Crispell, C.

    1978-01-01

    Data for specific joint design, utilizing various combinations of bolt, nut and lubricants in typical structure of the shuttle booster rocket is obtained. Requirements of the structure performance criteria were to withstand temperatures of 260 C (500 F) and to provide a nut lubricant which would be compatible with sealants used in the joint. Cadmium plating and dry film lubricant meeting the requirements of MIL-L-8937 were the lubricants specified. In a follow up effort, cadmium plating and cetyl alcohol were further specified The materials for the bolt and nut combinations were MP35N and A-286. These materials demand a lubricant to be used to prevent galling of the thread when tightened and also to help reduce the scatter of clamping load in application.

  12. Braze alloy spreading on steel

    NASA Technical Reports Server (NTRS)

    Siewert, T. A.; Heine, R. W.; Lagally, M. G.

    1978-01-01

    Scanning electron microscopy (SEM) and Auger electron microscopy (AEM) were employed to observe elemental surface decomposition resulting from the brazing of a copper-treated steel. Two types of steel were used for the study, stainless steel (treated with a eutectic silver-copper alloy), and low-carbon steel (treated with pure copper). Attention is given to oxygen partial pressure during the processes; a low enough pressure (8 x 10 to the -5th torr) was found to totally inhibit the spreading of the filler material at a fixed heating cycle. With both types of steel, copper treatment enhanced even spreading at a decreased temperature.

  13. Sensitization of stainless steel

    NASA Technical Reports Server (NTRS)

    Nagy, James P.

    1990-01-01

    The objective of this experiment is to determine the corrosion rates of 18-8 stainless steels that have been sensitized at various temperatures and to show the application of phase diagrams. The laboratory instructor will assign each student a temperature, ranging from 550 C to 1050 C, to which the sample will be heated. Further details of the experimental procedure are detailed.

  14. Laser Peening--Strengthening Metals to Improve Fatigue Lifetime and Retard Stress-Induced Corrosion Cracking in Gears, Bolts and Cutter

    SciTech Connect

    Hackel, L A; Chen, H-L

    2003-08-20

    Laser peening is an emerging modern process that impresses a compressive stress into the surfaces of metals. Treatment can reduce the rate of fatigue cracking and stress-corrosion-cracking in metals (such as gears, bolts and cutters) needed for tunnel boring and other construction & mining applications. Laser peening could also be used to form metals or alloys into a precise shape without yielding and leaving both sulfates in a crack resistant compressive state.

  15. Special steel production on common carbon steel production line

    NASA Astrophysics Data System (ADS)

    Pi, Huachun; Han, Jingtao; Hu, Haiping; Bian, Ruisheng; Kang, Jianjun; Xu, Manlin

    2004-06-01

    The equipment and technology of small bar tandem rolling line of Shijiazhuang Iron & Steel Co. in China has reached the 90's international advanced level in the 20th century, but products on the line are mostly of common carbon steel. Currently there are few steel plants in China to produce 45 steel bars for cold drawing, which is a kind of shortage product. Development of 45 steel for cold drawing has a wide market outlook in China. In this paper, continuous cooling transformation (CCT) curve of 45 steel for cold drawing used for rolling was set out first. According to the CCT curve, we determined some key temperature points such as Ac3 temperature and Ac1 temperature during the cooling procedure and discussed the precipitation microstructure at different cooling rate. Then by studying thermal treatment process of 45 steel bars for cold drawing, the influence of cooling time on microstructure was analyzed and the optimum cooling speed has been found. All results concluded from the above studies are the basis of regulating controlled cooling process of 45 steel bars for cold drawing. Finally, the feasible production process of 45 steel bars for cold drawing on common carbon steel production line combined with the field condition was recommended.

  16. Ferritic steel melt and FLiBe/steel experiment : melting ferritic steel.

    SciTech Connect

    Troncosa, Kenneth P.; Smith, Brandon M.; Tanaka, Tina Joan

    2004-11-01

    In preparation for developing a Z-pinch IFE power plant, the interaction of ferritic steel with the coolant, FLiBe, must be explored. Sandia National Laboratories Fusion Technology Department was asked to drop molten ferritic steel and FLiBe in a vacuum system and determine the gas byproducts and ability to recycle the steel. We tried various methods of resistive heating of ferritic steel using available power supplies and easily obtained heaters. Although we could melt the steel, we could not cause a drop to fall. This report describes the various experiments that were performed and includes some suggestions and materials needed to be successful. Although the steel was easily melted, it was not possible to drip the molten steel into a FLiBe pool Levitation melting of the drop is likely to be more successful.

  17. 46 CFR 59.20-1 - Carbon-steel or alloy-steel castings.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... BOILERS, PRESSURE VESSELS AND APPURTENANCES Welding Repairs to Castings § 59.20-1 Carbon-steel or alloy-steel castings. Defects in carbon-steel or alloy-steel castings may be repaired by welding. The...

  18. 46 CFR 59.20-1 - Carbon-steel or alloy-steel castings.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... BOILERS, PRESSURE VESSELS AND APPURTENANCES Welding Repairs to Castings § 59.20-1 Carbon-steel or alloy-steel castings. Defects in carbon-steel or alloy-steel castings may be repaired by welding. The...

  19. 46 CFR 59.20-1 - Carbon-steel or alloy-steel castings.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... BOILERS, PRESSURE VESSELS AND APPURTENANCES Welding Repairs to Castings § 59.20-1 Carbon-steel or alloy-steel castings. Defects in carbon-steel or alloy-steel castings may be repaired by welding. The...

  20. 46 CFR 59.20-1 - Carbon-steel or alloy-steel castings.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... BOILERS, PRESSURE VESSELS AND APPURTENANCES Welding Repairs to Castings § 59.20-1 Carbon-steel or alloy-steel castings. Defects in carbon-steel or alloy-steel castings may be repaired by welding. The...

  1. 46 CFR 59.20-1 - Carbon-steel or alloy-steel castings.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... BOILERS, PRESSURE VESSELS AND APPURTENANCES Welding Repairs to Castings § 59.20-1 Carbon-steel or alloy-steel castings. Defects in carbon-steel or alloy-steel castings may be repaired by welding. The...

  2. Assessment and evaluation of noise controls on roof bolting equipment and a method for predicting sound pressure levels in underground coal mining

    NASA Astrophysics Data System (ADS)

    Matetic, Rudy J.

    Over-exposure to noise remains a widespread and serious health hazard in the U.S. mining industries despite 25 years of regulation. Every day, 80% of the nation's miners go to work in an environment where the time weighted average (TWA) noise level exceeds 85 dBA and more than 25% of the miners are exposed to a TWA noise level that exceeds 90 dBA, the permissible exposure limit (PEL). Additionally, MSHA coal noise sample data collected from 2000 to 2002 show that 65% of the equipment whose operators exceeded 100% noise dosage comprise only seven different types of machines; auger miners, bulldozers, continuous miners, front end loaders, roof bolters, shuttle cars (electric), and trucks. In addition, the MSHA data indicate that the roof bolter is third among all the equipment and second among equipment in underground coal whose operators exceed 100% dosage. A research program was implemented to: (1) determine, characterize and to measure sound power levels radiated by a roof bolting machine during differing drilling configurations (thrust, rotational speed, penetration rate, etc.) and utilizing differing types of drilling methods in high compressive strength rock media (>20,000 psi). The research approach characterized the sound power level results from laboratory testing and provided the mining industry with empirical data relative to utilizing differing noise control technologies (drilling configurations and types of drilling methods) in reducing sound power level emissions on a roof bolting machine; (2) distinguish and correlate the empirical data into one, statistically valid, equation, in which, provided the mining industry with a tool to predict overall sound power levels of a roof bolting machine given any type of drilling configuration and drilling method utilized in industry; (3) provided the mining industry with several approaches to predict or determine sound pressure levels in an underground coal mine utilizing laboratory test results from a roof bolting

  3. The use of the direct optimized probabilistic calculation method in design of bolt reinforcement for underground and mining workings.

    PubMed

    Krejsa, Martin; Janas, Petr; Yilmaz, Işık; Marschalko, Marian; Bouchal, Tomas

    2013-01-01

    The load-carrying system of each construction should fulfill several conditions which represent reliable criteria in the assessment procedure. It is the theory of structural reliability which determines probability of keeping required properties of constructions. Using this theory, it is possible to apply probabilistic computations based on the probability theory and mathematic statistics. Development of those methods has become more and more popular; it is used, in particular, in designs of load-carrying structures with the required level or reliability when at least some input variables in the design are random. The objective of this paper is to indicate the current scope which might be covered by the new method-Direct Optimized Probabilistic Calculation (DOProC) in assessments of reliability of load-carrying structures. DOProC uses a purely numerical approach without any simulation techniques. This provides more accurate solutions to probabilistic tasks, and, in some cases, such approach results in considerably faster completion of computations. DOProC can be used to solve efficiently a number of probabilistic computations. A very good sphere of application for DOProC is the assessment of the bolt reinforcement in the underground and mining workings. For the purposes above, a special software application-"Anchor"-has been developed.

  4. Mechanical Design and Analysis of a 200 MHz, Bolt-together RFQ forthe Accelerator Driven Neutron Source

    SciTech Connect

    Virostek, Steve; Hoff, Matt; Li, Derun; Staples, John; Wells,Russell

    2007-06-20

    A high-yield neutron source to screen sea-land cargocontainers for shielded Special Nuclear Materials (SNM) has been designedat LBNL [1,2]. The Accelerator-Driven Neutron Source (ADNS) uses theD(d,n)3He reaction to create a forward directed neutron beam. Keycomponents are a high-current radio-frequency quadrupole (RFQ)accelerator and a high-power target capable of producing a neutron fluxof>107 n/(cm2 cdot s) at a distance of 2.5 m. The mechanical designand analysis of the four-module, bolt-together RFQ will be presentedhere. Operating at 200 MHz, the 5.1 m long RFQ will accelerate a 40 mAdeuteron beam to 6 MeV. At a 5 percent duty factor, the time-average d+beam current on target is 1.5 mA. Each of the 1.27 m long RFQ moduleswill consist of four solid OFHC copper vanes. A specially designed 3-DO-ring will provide vacuum sealing between both the vanes and themodules. RF connections are made with canted coil spring contacts. Aseries of 60 water-cooled pi-mode rods provides quadrupole modestabilization. A set of 80 evenly spaced fixed slug tuners is used forfinal frequency adjustment and local field perturbationcorrection.

  5. Design and evaluation of a bolted joint for a discrete carbon-epoxy rod-reinforced hat section

    NASA Technical Reports Server (NTRS)

    Rousseau, Carl Q.; Baker, Donald J.

    1996-01-01

    The use of prefabricated pultruded carbon-epoxy rods has reduced the manufacturing complexity and costs of stiffened composite panels while increasing the damage tolerance of the panels. However, repairability of these highly efficient discrete stiffeners has been a concern. Design, analysis, and test results are presented in this paper for a bolted-joint repair for the pultruded rod concept that is capable of efficiently transferring axial loads in a hat-section stiffener on the upper skin segment of a heavily loaded aircraft wing component. A tension and a compression joint design were evaluated. The tension joint design achieved approximately 1.0% strain in the carbon-epoxy rod-reinforced hat-section and failed in a metal fitting at 166% of the design ultimate load. The compression joint design failed in the carbon-epoxy rod-reinforced hat-section test specimen area at approximately 0.7% strain and at 110% of the design ultimate load. This strain level of 0.7% in compression is similar to the failure strain observed in previously reported carbon-epoxy rod-reinforced hat-section column tests.

  6. Design and Evaluation of a Bolted Joint for a Discrete Carbon-Epoxy Rod-Reinforced Hat Section

    NASA Technical Reports Server (NTRS)

    Baker, Donald J.; Rousseau, Carl Q.

    1996-01-01

    The use of pre-fabricated pultruded carbon-epoxy rods has reduced the manufacturing complexity and costs of stiffened composite panels while increasing the damage tolerance of the panels. However, repairability of these highly efficient discrete stiffeners has been a concern. Design, analysis, and test results are presented in this paper for a bolted-joint repair for the pultruded rod concept that is capable of efficiently transferring axial loads in a hat-section stiffener on the upper skin segment of a heavily loaded aircraft wing component. A tension and a compression joint design were evaluated. The tension joint design achieved approximately 1.0 percent strain in the carbon-epoxy rod-reinforced hat-section and failed in a metal fitting at 166 percent of the design ultimate load. The compression joint design failed in the carbon-epoxy rod-reinforced hat-section test specimen area at approximately 0.7 percent strain and at 110 percent of the design ultimate load. This strain level of 0.7 percent in compression is similar to the failure strain observed in previously reported carbon-epoxy rod-reinforced hat-section column tests.

  7. History of ultrahigh carbon steels

    SciTech Connect

    Wadsworth, J.; Sherby, O.D.

    1997-06-20

    The history and development of ultrahigh carbon steels (i.e., steels containing between 1 and 2.l percent C and now known as UHCS) are described. The early use of steel compositions containing carbon contents above the eutectoid level is found in ancient weapons from around the world. For example, both Damascus and Japanese sword steels are hypereutectoid steels. Their manufacture and processing is of interest in understanding the role of carbon content in the development of modern steels. Although sporadic examples of UHCS compositions are found in steels examined in the early part of this century, it was not until the mid-1970s that the modern study began. This study had its origin in the development of superplastic behavior in steels and the recognition that increasing the carbon content was of importance in developing that property. The compositions that were optimal for superplasticity involved the development of steels that contained higher carbon contents than conventional modern steels. It was discovered, however, that the room temperature properties of these compositions were of interest in their own right. Following this discovery, a period of intense work began on understanding their manufacture, processing, and properties for both superplastic forming and room temperature applications. The development of superplastic cast irons and iron carbides, as well as those of laminated composites containing UHCS, was an important part of this history.

  8. Respiratory status of stainless steel and mild steel welders.

    PubMed

    Kalliomäki, P L; Kalliomäki, K; Korhonen, O; Nordman, H; Rahkonen, E; Vaaranen, V

    1982-01-01

    Eighty-three full-time stainless steel and 29 mild steel welders from one shipyard were examined clinically, and their lung function was measured. The stainless steel welders had used both tungsten inert-gas (low-fume concentration) and manual metal-arc (MMA) (high-fume concentration) welding methods. The individual exposure of the welders was estimated based on the time spent doing MMA welding, the amount of retained contaminants in the lungs (magnetopulmography), and urinary chromium excretion. The results suggest that there is a greater prevalence of small airway disease among shipyard mild steel MMA welders than among stainless steel welders. Among the stainless steel welders the impairment of lung function parameters was associated with the MMA welding method. The type of welding, then, is important when the health hazards of welders are studied, and welders cannot be regarded as a single, homogeneous group. PMID:7100838

  9. Stainless Steel Permeability

    SciTech Connect

    Buchenauer, Dean A.; Karnesky, Richard A.

    2015-09-01

    An understanding of the behavior of hydrogen isotopes in materials is critical to predicting tritium transport in structural metals (at high pressure), estimating tritium losses during production (fission environment), and predicting in-vessel inventory for future fusion devices (plasma driven permeation). Current models often assume equilibrium diffusivity and solubility for a class of materials (e.g. stainless steels or aluminum alloys), neglecting trapping effects or, at best, considering a single population of trapping sites. Permeation and trapping studies of the particular castings and forgings enable greater confidence and reduced margins in the models. For FY15, we have continued our investigation of the role of ferrite in permeation for steels of interest to GTS, through measurements of the duplex steel 2507. We also initiated an investigation of the permeability in work hardened materials, to follow up on earlier observations of unusual permeability in a particular region of 304L forgings. Samples were prepared and characterized for ferrite content and coated with palladium to prevent oxidation. Issues with the poor reproducibility of measurements at low permeability were overcome, although the techniques in use are tedious. Funding through TPBAR and GTS were secured for a research grade quadrupole mass spectrometer (QMS) and replacement turbo pumps, which should improve the fidelity and throughput of measurements in FY16.

  10. Process for dezincing galvanized steel

    DOEpatents

    Morgan, William A.; Dudek, Frederick J.; Daniels, Edward J.

    1998-01-01

    A process for removing zinc from galvanized steel. The galvanized steel is immersed in an electrolyte containing at least about 15% by weight of sodium or potassium hydroxide and having a temperature of at least about 75.degree. C. and the zinc is galvanically corroded from the surface of the galvanized steel. The material serving as the cathode is principally a material having a standard electrode potential which is intermediate of the standard electrode potentials of zinc and cadmium in the electrochemical series. The corrosion rate may be accelerated by (i) increasing the number density of corrosion sites in the galvanized steel by mechanically abrading or deforming the galvanized steel, (ii) heating the galvanized steel to form an alloy of zinc on the surface of the galvanized steel, (iii) mixing the galvanized steel with a material having a standard electrode potential which is intermediate of the standard electrode potentials of zinc and cadmium in the electrochemical series, or (iv) moving the galvanized steel relative to itself and to the electrolyte while immersed in the electrolyte.

  11. Process for dezincing galvanized steel

    DOEpatents

    Morgan, W.A.; Dudek, F.J.; Daniels, E.J.

    1998-07-14

    A process is described for removing zinc from galvanized steel. The galvanized steel is immersed in an electrolyte containing at least about 15% by weight of sodium or potassium hydroxide and having a temperature of at least about 75 C and the zinc is galvanically corroded from the surface of the galvanized steel. The material serving as the cathode is principally a material having a standard electrode potential which is intermediate of the standard electrode potentials of zinc and cadmium in the electrochemical series. The corrosion rate may be accelerated by (1) increasing the number density of corrosion sites in the galvanized steel by mechanically abrading or deforming the galvanized steel, (2) heating the galvanized steel to form an alloy of zinc on the surface of the galvanized steel, (3) mixing the galvanized steel with a material having a standard electrode potential which is intermediate of the standard electrode potentials of zinc and cadmium in the electrochemical series, or (4) moving the galvanized steel relative to itself and to the electrolyte while immersed in the electrolyte. 1 fig.

  12. Induction heat treatment of steel

    SciTech Connect

    Semiatin, S.L.; Stutz, D.E.

    1985-01-01

    This book discusses the induction heating. After reviewing heat treating operations for steel and the principles of the heat treatment of steel, an overview of induction heat treating is provided. Next, consideration is given to equipment and equipment selection, coil design, power requirements and temperature control. A discussion of surface and through hardening of steel is provided, including information on frequency and power selection and quenching apparatus. Tempering is considered, followed by information on control of residual stresses, cracking, temper brittleness and the important metallurgical and hardness differences between induction and furnace treated steel.

  13. High strength, tough alloy steel

    DOEpatents

    Thomas, Gareth; Rao, Bangaru V. N.

    1979-01-01

    A high strength, tough alloy steel is formed by heating the steel to a temperature in the austenite range (1000.degree.-1100.degree. C.) to form a homogeneous austenite phase and then cooling the steel to form a microstructure of uniformly dispersed dislocated martensite separated by continuous thin boundary films of stabilized retained austenite. The steel includes 0.2-0.35 weight % carbon, at least 1% and preferably 3-4.5% chromium, and at least one other substitutional alloying element, preferably manganese or nickel. The austenite film is stable to subsequent heat treatment as by tempering (below 300.degree. C.) and reforms to a stable film after austenite grain refinement.

  14. Numerical modelling as a cost-reduction tool for probability of detection of bolt hole eddy current testing

    NASA Astrophysics Data System (ADS)

    Mandache, C.; Khan, M.; Fahr, A.; Yanishevsky, M.

    2011-03-01

    Probability of detection (PoD) studies are broadly used to determine the reliability of specific nondestructive inspection procedures, as well as to provide data for damage tolerance life estimations and calculation of inspection intervals for critical components. They require inspections on a large set of samples, a fact that makes these statistical assessments time- and cost-consuming. Physics-based numerical simulations of nondestructive testing inspections could be used as a cost-effective alternative to empirical investigations. They realistically predict the inspection outputs as functions of the input characteristics related to the test piece, transducer and instrument settings, which are subsequently used to partially substitute and/or complement inspection data in PoD analysis. This work focuses on the numerical modelling aspects of eddy current testing for the bolt hole inspections of wing box structures typical of the Lockheed Martin C-130 Hercules and P-3 Orion aircraft, found in the air force inventory of many countries. Boundary element-based numerical modelling software was employed to predict the eddy current signal responses when varying inspection parameters related to probe characteristics, crack geometry and test piece properties. Two demonstrator exercises were used for eddy current signal prediction when lowering the driver probe frequency and changing the material's electrical conductivity, followed by subsequent discussions and examination of the implications on using simulated data in the PoD analysis. Despite some simplifying assumptions, the modelled eddy current signals were found to provide similar results to the actual inspections. It is concluded that physics-based numerical simulations have the potential to partially substitute or complement inspection data required for PoD studies, reducing the cost, time, effort and resources necessary for a full empirical PoD assessment.

  15. The industrial ecology of steel

    SciTech Connect

    Considine, Timothy J.; Jablonowski, Christopher; Considine, Donita M.M.; Rao, Prasad G.

    2001-03-26

    This study performs an integrated assessment of new technology adoption in the steel industry. New coke, iron, and steel production technologies are discussed, and their economic and environmental characteristics are compared. Based upon detailed plant level data on cost and physical input-output relations by process, this study develops a simple mathematical optimization model of steel process choice. This model is then expanded to a life cycle context, accounting for environmental emissions generated during the production and transportation of energy and material inputs into steelmaking. This life-cycle optimization model provides a basis for evaluating the environmental impacts of existing and new iron and steel technologies. Five different plant configurations are examined, from conventional integrated steel production to completely scrap-based operations. Two cost criteria are used to evaluate technology choice: private and social cost, with the latter including the environmental damages associated with emissions. While scrap-based technologies clearly generate lower emissions in mass terms, their emissions of sulfur dioxide and nitrogen oxides are significantly higher. Using conventional damage cost estimates reported in the literature suggests that the social costs associated with scrap-based steel production are slightly higher than with integrated steel production. This suggests that adopting a life-cycle viewpoint can substantially affect environmental assessment of new technologies. Finally, this study also examines the impacts of carbon taxes on steel production costs and technology choice.

  16. Impact of Different Standard Type A7A Drum Closure-Ring Practices on Gasket Contraction and Bolt Closure Distance– 15621

    SciTech Connect

    Ketusky, Edward; Blanton, Paul; Bobbitt, John H.

    2015-03-11

    The Department of Energy, the Savannah River National Laboratory, several manufacturers of specification drums, and the United States Department of Transportation (DOT) are collaborating in the development of a guidance document for DOE contractors and vendors who wish to qualify containers to DOT 7A Type A requirements. Currently, the effort is focused on DOT 7A Type A 208-liter (55-gallons) drums with a standard 12-gauge bolted closure ring. The U.S. requirements, contained in Title 49, Part 178.350 “Specification 7A; general packaging, Type A specifies a competent authority review of the packaging is not required for the transport of (Class 7) radioactive material containing less than Type A quantities of radioactive material. For Type AF drums, a 4 ft. regulatory free drop must be performed, such that the drum “suffers maximum damage.” Although the actual orientation is not defined by the specification, recent studies suggest that maximum damage would result from a shallow angle top impact, where kinetic energy is transferred to the lid, ultimately causing heavy damage to the lid, or even worse, causing the lid to come off. Since each vendor develops closure recommendations/procedures for the drums they manufacture, key parameters applied to drums during closing vary based on vendor. As part of the initial phase of the collaboration, the impact of the closure variants on the ability of the drum to suffer maximum damage is investigated. Specifically, closure testing is performed varying: 1) the amount of torque applied to the closure ring bolt; and, 2) stress relief protocol, including: a) weight of hammer; and, b) orientation that the hammer hits the closure ring. After closure, the amount of drum lid gasket contraction and the distance that the closure bolt moves through the closure ring is measured.

  17. Use of two-dimensional transmission photoelastic models to study stresses in double-lap bolted joints: Load transfer and stresses in the inner lap

    NASA Technical Reports Server (NTRS)

    Hyer, M. W.

    1980-01-01

    The determination of the stress distribution in the inner lap of double-lap, double-bolt joints using photoelastic models of the joint is discussed. The principal idea is to fabricate the inner lap of a photoelastic material and to use a photoelastically sensitive material for the two outer laps. With this setup, polarized light transmitted through the stressed model responds principally to the stressed inner lap. The model geometry, the procedures for making and testing the model, and test results are described.

  18. Connections: Superplasticity, Damascus Steels, Laminated Steels, and Carbon Dating

    NASA Astrophysics Data System (ADS)

    Wadsworth, Jeffrey

    2016-09-01

    In this paper, a description is given of the connections that evolved from the initial development of a family of superplastic plain carbon steels that came to be known as Ultra-High Carbon Steels (UHCS). It was observed that their very high carbon contents were similar, if not identical, to those of Damascus steels. There followed a series of attempts to rediscover how the famous patterns found on Damascus steels blades were formed. At the same time, in order to improve the toughness at room temperature of the newly-developed UHCS, laminated composites were made of alternating layers of UHCS and mild steel (and subsequently other steels and other metals). This led to a study of ancient laminated composites, the motives for their manufacture, and the plausibility of some of the claims relating to the number of layers in the final blades. One apparently ancient laminated composite, recovered in 1837 from the great pyramid of Giza which was constructed in about 2750 B.C., stimulated a carbon dating study of ancient steels. The modern interest in "Bladesmithing" has connections back to many of these ancient weapons.

  19. Occupational Profiles in the European Steel Industry.

    ERIC Educational Resources Information Center

    Franz, Hans-Werner; And Others

    The steel industry in Europe has faced great changes, with resulting layoffs and restructuring. Now that the most basic changes seem to be over, it has become evident that the remaining steel industry requires more highly trained workers than was the case previously. Although steel maintenance employees were always highly skilled, steel production…

  20. Improving the toughness of ultrahigh strength steel

    SciTech Connect

    Soto, Koji

    2002-08-15

    The ideal structural steel combines high strength with high fracture toughness. This dissertation discusses the toughening mechanism of the Fe/Co/Ni/Cr/Mo/C steel, AerMet 100, which has the highest toughness/strength combination among all commercial ultrahigh strength steels. The possibility of improving the toughness of this steel was examined by considering several relevant factors.

  1. Irradiation effects in ferritic steels

    NASA Astrophysics Data System (ADS)

    Lechtenberg, Thomas

    1985-08-01

    Since 1979 the Alloy Development for Irradiation Performance (ADIP) task funded by the US Department of Energy has been studying the 2-12Cr class of ferritic steels to establish the feasibility of using them in fusion reactor first wall/breeding blanket (FW/B) applications. The advantages of ferritic steels include superior swelling resistance, low thermal stresses compared to austenitic stainless steels, attractive mechanical properties up to 600°C. and service histories exceeding 100 000 h. These steels are commonly used in a range of microstructural conditions which include ferritic, martensitic. tempered martensitic, bainitic etc. Throughout this paper where the term "ferritic" is used it should be taken to mean any of these microstructures. The ADIP task is studying several candidate alloy systems including 12Cr-1MoWV (HT-9), modified 9Cr-1MoVNb, and dual-phased steels such as EM-12 and 2 {1}/{4}Cr-Mo. These materials are ferromagnetic (FM), body centered cubic (bcc), and contain chromium additions between 2 and 12 wt% and molybdenum additions usually below 2%. The perceived issues associated with the application of this class of steel to fusion reactors are the increase in the ductile-brittle transition temperature (DBTT) with neutron damage, the compatibility of these steels with liquid metals and solid breeding materials, and their weldability. The ferromagnetic character of these steels can also be important in reactor design. It is the purpose of this paper to review the current understanding of these bcc steels and the effects of irradiation. The major points of discussion will be irradiation-induced or -enhanced dimensional changes such as swelling and creep, mechanical properties such as tensile strength and various measurements of toughness, and activation by neutron interactions with structural materials.

  2. Assessment of void swelling in austenitic stainless steel PWR core internals.

    SciTech Connect

    Chung, H. M.; Energy Technology

    2006-01-31

    As many pressurized water reactors (PWRs) age and life extension of the aged plants is considered, void swelling behavior of austenitic stainless steel (SS) core internals has become the subject of increasing attention. In this report, the available database on void swelling and density change of austenitic SSs was critically reviewed. Irradiation conditions, test procedures, and microstructural characteristics were carefully examined, and key factors that are important to determine the relevance of the database to PWR conditions were evaluated. Most swelling data were obtained from steels irradiated in fast breeder reactors at temperatures >385 C and at dose rates that are orders of magnitude higher than PWR dose rates. Even for a given irradiation temperature and given steel, the integral effects of dose and dose rate on void swelling should not be separated. It is incorrect to extrapolate swelling data on the basis of 'progressive compounded multiplication' of separate effects of factors such as dose, dose rate, temperature, steel composition, and fabrication procedure. Therefore, the fast reactor data should not be extrapolated to determine credible void swelling behavior for PWR end-of-life (EOL) or life-extension conditions. Although the void swelling data extracted from fast reactor studies is extensive and conclusive, only limited amounts of swelling data and information have been obtained on microstructural characteristics from discharged PWR internals or steels irradiated at temperatures and at dose rates comparable to those of a PWR. Based on this relatively small amount of information, swelling in thin-walled tubes and baffle bolts in a PWR is not considered a concern. As additional data and relevant research becomes available, the newer results should be integrated with existing data, and the worthiness of this conclusion should continue to be scrutinized. PWR baffle reentrant corners are the most likely location to experience high swelling rates, and

  3. Bubble resorption in rhyolitic melts: Insight from open-system vesiculation experiments using bolt/nut cells

    NASA Astrophysics Data System (ADS)

    Yoshimura, S.; Nakamura, M.

    2006-12-01

    The open-system degassing is an essential process in non-explosive eruption of hydrous silicic magmas. Permeable flow degassing through interconnected bubble networks is considered to be the main mode that enables rapid removal of bubbles, but additional processes are required for the formation of bubble-free magmas, as the networks become disconnected and bubbles get isolated when vesicularity decreases below the percolation threshold via progressive permeable flow. To investigate the behavior of bubbles in the late stage of permeable flow degassing, we conducted a series of vesiculation experiments on rhyolitic melts in a newly designed semipermeable bolt/nut cell. The starting material was natural rhyolitic obsidian with ca. 0.67 wt.% initial water content. The obsidian cores, which were typically 10 vol.% smaller than the sample chamber, were heated in the cell at 1000 ° C for 7 periods ranging from 1 to 288 hours. As the cell is strong enough to resist the inner pressure associated with the vesiculation of the obsidian, the volume of sample chamber is kept constant, while the vapor can escape the cell through a narrow interspace. The run charges generally show a zonal structure composed of two contrasting regions: a central region within which bubbles are concentrated (bubble-rich core; BC) and a bubble-free melt region surrounding the BC (bubble-free margin; BFM). With increasing duration of heating, the thickness of the BFM and vesicularity of the BC increased, while the water content of the BC decreased. The outermost bubbles (i.e., bubbles on the BFM-BC boundary) were significantly smaller than inner bubbles. Water content of melt was nearly uniform throughout the BC, whereas an outward-decreasing gradient was observed in the BFM. These observations can be explained by (1) uniform vesiculation of the starting obsidian with filling the sample chamber, (2) dehydration of melt at the sample surface via diffusion of water, (3) bubble resorption into the

  4. Arts-inspired students sync their assets to a nuts and bolts world: A career mentoring pilot progam

    NASA Astrophysics Data System (ADS)

    Hudson, Lynn

    This research examined how students who are arts-inspired feel about their futures in a STEM-based work climate. Science, Technology, Engineering, and Math are the nuts and bolts, and in education today, the only avenue touted for our country and our students' success in this 21st century economy. This can be disconcerting to those interested in other fields, like the arts. This study was guided by the following questions in an effort to understand if our artists and arts-inspired students realize their options and importance in this 21st century climate. The pilot study was designed to help improve the students' perception of their abilities or self-efficacy in the STEM areas by introducing STEM professionals as mentors who designed hands-on activities that simulate work in the STEM fields. Research Questions: 1. Do arts-inspired students have an interest in a STEM career area prior to participating in the career mentoring program? 2. Does participation in a STEM career mentoring program improve student's self-efficacy in STEM fields? 3. Does participation in STEM career mentoring program increase student's interest in pursuing STEM-related careers? Lent, Brown and Hackett's Social Cognitive Career Theory and Daniel Pink's, "A Whole New Mind: Why Left-Brainers Will Rule the Future" were used as the theoretical framework for this study. Seventeen African-American girls who were enrolled in the "I AM COMPLETE" summer program participated in the pilot study. Data was collected from the College Foundation of North Carolina Career Interest Explorer and the STEM Career Interest Survey, which served as a pre and post-test. This pilot offered limited support for the hypothesis, however, career mentoring and opportunities for young people to experience careers, especially in the STEM areas must continue to grow. The role that the arts play in this process is pivotal in galvanizing females and minorities to join these professions. It is the hope of this researcher that the

  5. Development of an impact-reduction device by applying ultrasonic vibrations to a high-strength steel plate using a downsized transducer

    NASA Astrophysics Data System (ADS)

    Suzuki, Atsuyuki; Ikeoka, Shota; Tsujino, Jiromaru

    2016-07-01

    In this study, we attempted to downsize an ultrasonic impact-reduction device and studied its use in vehicles because the use of large devices increases the overall vehicle weight and size and reduces fuel economy. We downsized the ultrasonic transducer to 195 mm from 435 mm and measured the vibration, deformation, and impact-reduction characteristics. The resonant frequency changed after a bolt-clamped Langevin-type transducer was connected with the horn, and the motional admittance decreased. Upon application of ultrasonic vibrations to a high-strength steel plate, the deformation magnitude increased, the springback magnitude decreased by up to 25%, and the impact force decreased by 18%. While the downsized impact reduction system was found to be less effective, it still showed an impact reduction effect.

  6. Welding tritium exposed stainless steel

    SciTech Connect

    Kanne, W.R. Jr.

    1994-11-01

    Stainless steels that are exposed to tritium become unweldable by conventional methods due to buildup of decay helium within the metal matrix. With longer service lives expected for tritium containment systems, methods for welding on tritium exposed material will become important for repair or modification of the systems. Solid-state resistance welding and low-penetration overlay welding have been shown to mitigate helium embrittlement cracking in tritium exposed 304 stainless steel. These processes can also be used on stainless steel containing helium from neutron irradiation, such as occurs in nuclear reactors.

  7. Analysis of Vibrating Circular Plates Having Non-Uniform Constraints Using the Modal Properties of Free-Edge Plates: Application to Bolted Plates

    NASA Astrophysics Data System (ADS)

    Amabili, M.; Pierandrei, R.; Frosali, G.

    1997-09-01

    The free vibrations of a circular plate having elastic constraints variable according to the angular co-ordinate are investigated. The non-uniform translational and rotational stiffness of the constraints are expanded in the Fourier series; it is assumed that the system presents a symmetry axis. The mode shapes are expanded in a Fourier-Bessel series by using the Rayleigh-Ritz method. The eigenfunctions of the free-edge circular plate vibrating in vacuum are assumed as admissible functions. This choice allows one to compute the potential energy of the plate using the kinetic energy of single modes of free-edge plates. The effect of the in-plane load is included and internal constraints are studied. By using the same technique, the free vibrations of a circular plate resting on an annular, non-uniform, Winkler foundation are investigated. Numerical results are given for the cases studied already, in order to validate the proposed method, and for bolted (or riveted) plates fixed by different numbers of bolts.

  8. [CT-findings in penetrating captive bolt injuries to the head and brain: analysis of the trauma-related CT-findings and review of the literature].

    PubMed

    Bula-Sternberg, J; Laniado, M; Kittner, T; Bonnaire, F; Lein, T; Bula, P

    2011-11-01

    Penetrating gunshot injuries to the head and brain are rare in Germany and the rest of Western Europe. Due to the small number of cases over here no consistent diagnostic and therapeutic standards exist in this respect. Thus these kinds of injuries present a great challenge to the attending physicians. Most of these violations are a result of a suicidal attempt or an accident. Beside violations by firearms also penetrating injuries to the head and brain due to captive bolt devices, as used in slaughtery business for the "humane" killing of animals, occur from time to time. The impact on the head differs from that caused by firearms because no projectile is leaving the barrel and the used bolt, as a fix part of the device, does not remain in the affected tissue. That implies characteristic results within the radiological imaging that might be pathbreaking for the further treatment, because the origin of such a head injury is often unknown during primary care. Consequently the knowledge of these specific findings is central to the radiologist to make the appropriate diagnosis. Based on some clinical examples the trauma-related CT-findings are introduced and a short overview of the relevant literature is also given.

  9. Testing and evaluation of Vespel up to 450 deg F when used in nuts and bolts as a self-locking element

    NASA Technical Reports Server (NTRS)

    Wood, C. M.

    1984-01-01

    The object of this investigation was to evaluate Vespel for potential application on the Solid Rocket Booster to replace all-metal deformed self-locking nuts and anchor nuts and be used as self-locking elements for bolts and screws. The Vespel self-locking elements were tested for prevailing torque retention at room temperature, after heating to 450 F and exposure for 3 hr, breakaway torque at 450 F and for vibration at a level consistent with the maximum expected on the SRB at lift-off and reentry. The investigation revealed Vespel has properties that can provide a self-locking capability for threaded fasteners up to 450 F and it can be used in nuts and anchor nuts for installation on the SRB. Vespel elements in bolts did not meet all our SRB requirements for reuse, however, we have defined a design for Vespel elements in nuts/anchor nuts that fully meets all requirements. It is recommended that No. 1, 1/4 in. and 5/16 in. nuts/anchor nuts be procured for use on the SRB. This system will eliminate the galling problems now encountered and achieve a much higher reuse life than the present deformed nut design.

  10. Strength of graphite/epoxy bolted wing-skin splice specimens subjected to outdoor exposure under constant load and yearly fatigue loading

    NASA Technical Reports Server (NTRS)

    Wichorek, G. R.; Crews, J. H., Jr.

    1986-01-01

    The results of an experimental study to provide long-term durability data on detailed full-scale graphite/epoxy wing-skin joint designs under environmental exposure and cyclic loading associated with commercial transport aircraft are reported. The specimens consisted of a single-row bolt configuration fabricated from T300/5208 and a double-row bolt configuration fabricated from T300/5209. The unpainted specimens were exposed to the outdoor environment under a sustained tensile load, and at yearly intervals, they were subjected to fatigue loading. Experimental results showed a slight reduction in residual tensile strength for both graphite/epoxy joints under the exposure times and fatigue loadings reported. A 7.5-percent decrease in residual strength was observed for the T300/5208 single-row joint after 5 years exposure and two lifetimes of fatigue loading. A 5.3-percent decrease in residual strength was observed for the T300/5209 double-row joint after 7 years exposure and 2.8 lifetimes of fatigue loading. The 5208 epoxy material was more susceptible to degradation by ultraviolet radiation than the 5209 epoxy material.

  11. Advanced steel reheat furnace

    SciTech Connect

    Moyeda, D.; Sheldon, M.; Koppang, R.; Lanyi, M.; Li, X.; Eleazer, B.

    1997-10-01

    Energy and Environmental Research Corp. (EER) under a contract from the Department of Energy is pursuing the development and demonstration of an Advanced Steel Reheating Furnace. This paper reports the results of Phase 1, Research, which has evaluated an advanced furnace concept incorporating two proven and commercialized technologies previously applied to other high temperature combustion applications: EER`s gas reburn technology (GR) for post combustion NOx control; and Air Product`s oxy-fuel enrichment air (OEA) for improved flame heat transfer in the heating zones of the furnace. The combined technologies feature greater production throughput with associated furnace efficiency improvements; lowered NOx emissions; and better control over the furnace atmosphere, whether oxidizing or reducing, leading to better control over surface finish.

  12. 2169 steel waveform experiments.

    SciTech Connect

    Furnish, Michael David; Alexander, C. Scott; Reinhart, William Dodd; Brown, Justin L.

    2012-11-01

    In support of LLNL efforts to develop multiscale models of a variety of materials, we have performed a set of eight gas gun impact experiments on 2169 steel (21% Cr, 6% Ni, 9% Mn, balance predominantly Fe). These experiments provided carefully controlled shock, reshock and release velocimetry data, with initial shock stresses ranging from 10 to 50 GPa (particle velocities from 0.25 to 1.05 km/s). Both windowed and free-surface measurements were included in this experiment set to increase the utility of the data set, as were samples ranging in thickness from 1 to 5 mm. Target physical phenomena included the elastic/plastic transition (Hugoniot elastic limit), the Hugoniot, any phase transition phenomena, and the release path (windowed and free-surface). The Hugoniot was found to be nearly linear, with no indications of the Fe phase transition. Releases were non-hysteretic, and relatively consistent between 3- and 5-mmthick samples (the 3 mm samples giving slightly lower wavespeeds on release). Reshock tests with explosively welded impactors produced clean results; those with glue bonds showed transient releases prior to the arrival of the reshock, reducing their usefulness for deriving strength information. The free-surface samples, which were steps on a single piece of steel, showed lower wavespeeds for thin (1 mm) samples than for thicker (2 or 4 mm) samples. A configuration used for the last three shots allows release information to be determined from these free surface samples. The sample strength appears to increase with stress from ~1 GPa to ~ 3 GPa over this range, consistent with other recent work but about 40% above the Steinberg model.

  13. Corrosion of Steels in Steel Reinforced Concrete in Cassava Juice

    NASA Astrophysics Data System (ADS)

    Oluwadare, G. O.; Agbaje, O.

    The corrosion of two types of construction steels, ST60Mn and RST37-2♦, in a low cyanide concentration environment (cassava juice) and embedded in concrete had been studied. The ST60 Mn was found to be more corrosion resistant in both ordinary water and the cassava juice environment. The cyanide in cassava juice does not attack the steel but it provides an environment of lower pH around the steel in the concrete which leads to breakdown of the passivating film provided by hydroxyl ions from cement. Other factors such as the curing time of the concrete also affect the corrosion rates of the steel in the concrete. The corrosion rate of the steel directly exposed to cassava juice i.e., steel not embedded in concrete is about twice that in concrete. Long exposure of concrete structure to cassava processing effluent might result in deterioration of such structures. Careful attention should therefore be paid to disposal of cassava processing effluents, especially in a country like Nigeria where such processing is now on the increase.

  14. Great Lakes Steel -- PCI facility

    SciTech Connect

    Eichinger, F.T.; Dake, S.H.; Wagner, E.D.; Brown, G.S.

    1997-12-31

    This paper discusses the planning, design, and start-up of the 90 tph PCI facility for National Steel`s Great Lakes Steel Division in River Rouge, MI. This project is owned and operated by Edison Energy Services, and was implemented on a fast-track basis by Raytheon Engineers and Constructors, Babcock Material Handling, and Babcock and Wilcox. This paper presents important process issues, basic design criteria, an the challenges of engineering and building a state-of-the-art PCI facility in two existing plants. Pulverized coal is prepared at the River Rouge Power Plant of Detroit Edison, is pneumatically conveyed 6,000 feet to a storage silo at Great Lakes Steel, and is injected into three blast furnaces.

  15. Hydrogen embrittlement of structural steels.

    SciTech Connect

    Somerday, Brian P.

    2010-06-01

    Carbon-manganese steels are candidates for the structural materials in hydrogen gas pipelines, however it is well known that these steels are susceptible to hydrogen embrittlement. Decades of research and industrial experience have established that hydrogen embrittlement compromises the structural integrity of steel components. This experience has also helped identify the failure modes that can operate in hydrogen containment structures. As a result, there are tangible ideas for managing hydrogen embrittement in steels and quantifying safety margins for steel hydrogen containment structures. For example, fatigue crack growth aided by hydrogen embrittlement is a key failure mode for steel hydrogen containment structures subjected to pressure cycling. Applying appropriate structural integrity models coupled with measurement of relevant material properties allows quantification of safety margins against fatigue crack growth in hydrogen containment structures. Furthermore, application of these structural integrity models is aided by the development of micromechanics models, which provide important insights such as the hydrogen distribution near defects in steel structures. The principal objective of this project is to enable application of structural integrity models to steel hydrogen pipelines. The new American Society of Mechanical Engineers (ASME) B31.12 design code for hydrogen pipelines includes a fracture mechanics-based design option, which requires material property inputs such as the threshold for rapid cracking and fatigue crack growth rate under cyclic loading. Thus, one focus of this project is to measure the rapid-cracking thresholds and fatigue crack growth rates of line pipe steels in high-pressure hydrogen gas. These properties must be measured for the base materials but more importantly for the welds, which are likely to be most vulnerable to hydrogen embrittlement. The measured properties can be evaluated by predicting the performance of the pipeline

  16. Wear of steel by rubber

    NASA Technical Reports Server (NTRS)

    Gent, A. N.; Pulford, C. T. R.

    1978-01-01

    Wear of a steel blade used as a scraper to abrade rubber surfaces has been found to take place much more rapidly on a cis-polyisoprene (natural rubber) surface than on a cis-polybutadiene surface, and much more rapidly in an inert atmosphere than in air. These observations are attributed to the direct attack upon steel of free-radical species generated by mechanical rupture of elastomer molecules during abrasion.

  17. Fatigue handbook: Offshore steel structures

    SciTech Connect

    Almarnaess, A.

    1985-01-01

    The contents of this book are: Overview of Offshore Steel Structures; Loads on Ocean Structures; Fracture Mechanics As a Tool in Fatigue Analysis; Basic Fatigue Properties of Welded Joints; Significance of Defects; Improving the Fatigue Strength of Welded Joints; Effects of Marine Environment and Cathodic Protection on Fatigue of Structural Steels Fatigue of Tubular Joints; Unstable Fracture; Fatigue Life Calculations; and Fatigue in Building Codes Background and Applications.

  18. Tamper indicating bolt

    DOEpatents

    Blagin, Sergei V.; Barkanov, Boris P.

    2004-09-14

    A tamper-indicating fastener has a cylindrical body with threads extending from one end along a portion of the body, and a tamper indicating having a transducer for converting physical properties of the body into electronic data; electronics for recording the electronic data; and means for communicating the recorded information to a remote location from said fastener. The electronics includes a capacitor that varies as a function of force applied by the fastener, and non-volatile memory for recording instances when the capacitance varies, providing an indication of unauthorized access.

  19. Roof bolt hole groover

    SciTech Connect

    Not Available

    1985-11-05

    A hole groover comprising a pair of grooving bits radially protruding from the surface of a drill rod and connected to swivel upwardly and downwardly near the end of the drill rod where the drill bit is connected. A connecting rod is connected to the inside ends of the groove bits and causes arcuate movement of the grooving bits as it reciprocates. The hole groover further includes a gear box which is connectable to a rotary drilling unit which converts rotational movement of the rotary drill until to reciprocating movement of a lever. The lever is connected to the connecting rod which causes movement of the grooving bits. The device is readily adaptable to be connected to most rotary drill units and the depth and intervals of the grooves can be easily controlled by adjusting the length of the grooving bits and the gear ratios. The device enables grooves to be cut in a wall hole surface, concurrently with the drilling of the hole.

  20. Hydrogen Permeation in Nanostructured Bainitic Steel

    NASA Astrophysics Data System (ADS)

    Kazum, Oluwole; Beladi, Hossein; Timokhina, Ilana B.; He, Yinghe; Bobby Kannan, M.

    2016-07-01

    Hydrogen permeation of nanostructured bainitic steel, produced at two different transformation temperatures, i.e., 473.15 K (200 °C) BS-200 and 623.15 K (350 °C) BS-350, was determined using Devanathan-Stachurski hydrogen permeation cell and compared with that of mild steel. Nanostructured bainitic steel showed lower effective diffusivity of hydrogen as compared to the mild steel. The BS-200 steel, which exhibited higher volume fraction of bainitic ferrite phase, showed lower effective diffusivity than BS-350 steel. The finer microstructural constituents (bainitic ferrite laths and retained austenite films) and higher dislocation density in the bainitic ferrite phase of BS-200 steel can be attributed to its lower effective diffusivity as compared to BS-350 steel and mild steel.

  1. Hydrogen Permeation in Nanostructured Bainitic Steel

    NASA Astrophysics Data System (ADS)

    Kazum, Oluwole; Beladi, Hossein; Timokhina, Ilana B.; He, Yinghe; Bobby Kannan, M.

    2016-10-01

    Hydrogen permeation of nanostructured bainitic steel, produced at two different transformation temperatures, i.e., 473.15 K (200 °C) BS-200 and 623.15 K (350 °C) BS-350, was determined using Devanathan-Stachurski hydrogen permeation cell and compared with that of mild steel. Nanostructured bainitic steel showed lower effective diffusivity of hydrogen as compared to the mild steel. The BS-200 steel, which exhibited higher volume fraction of bainitic ferrite phase, showed lower effective diffusivity than BS-350 steel. The finer microstructural constituents (bainitic ferrite laths and retained austenite films) and higher dislocation density in the bainitic ferrite phase of BS-200 steel can be attributed to its lower effective diffusivity as compared to BS-350 steel and mild steel.

  2. Design, analysis and application of innovative composite PR connections between steel beams and CFT columns

    NASA Astrophysics Data System (ADS)

    Hu, Jong Wan; Choi, Eunsoo; Leon, Roberto T.

    2011-02-01

    In this research, three structural design concepts are integrated: the use of composite concrete-filled tube (CFT) columns, the use of partially restrained (PR) connections and the introduction of innovative materials (shape memory alloys) in the connection design. These concepts are used to enhance the robustness and performance of composite-special moment frames. These innovative connections intend to exploit the recentering properties of super-elastic SMA tension bars, the energy dissipation capacity of low-carbon steel bars and the toughness of CFT columns. PR-CFT connection prototypes were designed based on a hierarchy of strength models for each connection component. Simplified user joint elements based on the mechanical modeling approach were formulated in an effort to simulate the realistic behavior of bolted connections. The application of new connections to low-rise PR composite frames is illustrated by designing four buildings in both 2D and 3D for the western US region. The performance of these composite frames was compared with those with conventional welded frames in terms of strength, ductility and recentering behavior. In all three areas, frames with the PR composite connections showed superior performance. This is due primarily to the capability of this system to redistribute inter-story drift more evenly through the height of the frame.

  3. 38. Photocopy of photograph. STEEL PLANT, BOILERS UNDER CONSTRUCTION IN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    38. Photocopy of photograph. STEEL PLANT, BOILERS UNDER CONSTRUCTION IN BOILER PLANT LOCATED EAST OF MAIN STEEL PLANT, 1909. (From the Bethlehem Steel Corporation collection, Seattle, WA) - Irondale Iron & Steel Plant, Port Townsend, Jefferson County, WA

  4. Anodized Steel Electrodes for Supercapacitors.

    PubMed

    Sagu, Jagdeep S; Wijayantha, K G Upul; Bohm, Mallika; Bohm, Siva; Kumar Rout, Tapan

    2016-03-01

    Steel was anodized in 10 M NaOH to enhance its surface texture and internal surface area for application as an electrode in supercapacitors. A mechanism was proposed for the anodization process. Field-emission gun scanning electron microscopy (FEGSEM) studies of anodized steel revealed that it contains a highly porous sponge like structure ideal for supercapacitor electrodes. X-ray photoelectron spectroscopy (XPS) measurements showed that the surface of the anodized steel was Fe2O3, whereas X-ray diffraction (XRD) measurements indicated that the bulk remained as metallic Fe. The supercapacitor performance of the anodized steel was tested in 1 M NaOH and a capacitance of 18 mF cm(-2) was obtained. Cyclic voltammetry measurements showed that there was a large psueudocapacitive contribution which was due to oxidation of Fe to Fe(OH)2 and then further oxidation to FeOOH, and the respective reduction of these species back to metallic Fe. These redox processes were found to be remarkably reversible as the electrode showed no loss in capacitance after 10000 cycles. The results demonstrate that anodization of steel is a suitable method to produce high-surface-area electrodes for supercapacitors with excellent cycling lifetime. PMID:26891093

  5. Anodized Steel Electrodes for Supercapacitors.

    PubMed

    Sagu, Jagdeep S; Wijayantha, K G Upul; Bohm, Mallika; Bohm, Siva; Kumar Rout, Tapan

    2016-03-01

    Steel was anodized in 10 M NaOH to enhance its surface texture and internal surface area for application as an electrode in supercapacitors. A mechanism was proposed for the anodization process. Field-emission gun scanning electron microscopy (FEGSEM) studies of anodized steel revealed that it contains a highly porous sponge like structure ideal for supercapacitor electrodes. X-ray photoelectron spectroscopy (XPS) measurements showed that the surface of the anodized steel was Fe2O3, whereas X-ray diffraction (XRD) measurements indicated that the bulk remained as metallic Fe. The supercapacitor performance of the anodized steel was tested in 1 M NaOH and a capacitance of 18 mF cm(-2) was obtained. Cyclic voltammetry measurements showed that there was a large psueudocapacitive contribution which was due to oxidation of Fe to Fe(OH)2 and then further oxidation to FeOOH, and the respective reduction of these species back to metallic Fe. These redox processes were found to be remarkably reversible as the electrode showed no loss in capacitance after 10000 cycles. The results demonstrate that anodization of steel is a suitable method to produce high-surface-area electrodes for supercapacitors with excellent cycling lifetime.

  6. Multiphysics modeling of the steel continuous casting process

    NASA Astrophysics Data System (ADS)

    Hibbeler, Lance C.

    This work develops a macroscale, multiphysics model of the continuous casting of steel. The complete model accounts for the turbulent flow and nonuniform distribution of superheat in the molten steel, the elastic-viscoplastic thermal shrinkage of the solidifying shell, the heat transfer through the shell-mold interface with variable gap size, and the thermal distortion of the mold. These models are coupled together with carefully constructed boundary conditions with the aid of reduced-order models into a single tool to investigate behavior in the mold region, for practical applications such as predicting ideal tapers for a beam-blank mold. The thermal and mechanical behaviors of the mold are explored as part of the overall modeling effort, for funnel molds and for beam-blank molds. These models include high geometric detail and reveal temperature variations on the mold-shell interface that may be responsible for cracks in the shell. Specifically, the funnel mold has a column of mold bolts in the middle of the inside-curve region of the funnel that disturbs the uniformity of the hot face temperatures, which combined with the bending effect of the mold on the shell, can lead to longitudinal facial cracks. The shoulder region of the beam-blank mold shows a local hot spot that can be reduced with additional cooling in this region. The distorted shape of the funnel mold narrow face is validated with recent inclinometer measurements from an operating caster. The calculated hot face temperatures and distorted shapes of the mold are transferred into the multiphysics model of the solidifying shell. The boundary conditions for the first iteration of the multiphysics model come from reduced-order models of the process; one such model is derived in this work for mold heat transfer. The reduced-order model relies on the physics of the solution to the one-dimensional heat-conduction equation to maintain the relationships between inputs and outputs of the model. The geometric

  7. High-temperature brazing of stainless steel

    NASA Technical Reports Server (NTRS)

    Beuyukian, C. S.; Heisman, R. M.; Mitchell, M. J.

    1978-01-01

    Prevention of iron contamination of platens is eliminated by placing alumina/silica ceramic-fiber blankets between platens and carbon-steel plate. Carbon-steel plates provide rigidity and improve heat transfer.

  8. Steel erected at A-3 Test Stand

    NASA Technical Reports Server (NTRS)

    2008-01-01

    Workers erect the first fabricated steel girders to arrive at the A-3 Test Stand at Stennis Space Center. Steel work began at the construction site Oct. 29 and is scheduled to continue into next spring.

  9. Corrosion control of steel-reinforced concrete

    NASA Astrophysics Data System (ADS)

    Chung, D. D. L.

    2000-10-01

    The methods and materials for corrosion control of steel-reinforced concrete are reviewed. The methods are steel surface treatment, the use of admixtures in concrete, surface coating on concrete, and cathodic protection.

  10. ESF GROUND SUPPORT - STRUCTURAL STEEL ANALYSIS

    SciTech Connect

    T. Misiak

    1996-06-26

    The purpose and objective of this analysis are to expand the level of detail and confirm member sizes for steel sets included in the Ground Support Design Analysis, Reference 5.20. This analysis also provides bounding values and details and defines critical design attributes for alternative configurations of the steel set. One possible configuration for the steel set is presented. This analysis covers the steel set design for the Exploratory Studies Facility (ESF) entire Main Loop 25-foot diameter tunnel.

  11. Steel erected at A-3 Test Stand

    NASA Technical Reports Server (NTRS)

    2008-01-01

    Fabricated steel began arriving by truck Oct. 24 for construction of the A-3 Test Stand that will be used to test the engine for the nation's next generation of moon rockets. Within days workers from Lafayette Steel Erector Inc. began assembling the 16 steel stages needed on the foundation and footings poured in the previous year.

  12. Steeling and Resilience in Art Education

    ERIC Educational Resources Information Center

    Heise, Donalyn

    2014-01-01

    Steel is an incredibly strong alloy of iron and carbon. Due to its incredible strength and durability, this resilient material is commonly used for constructing buildings. The transitive verb "steeling" is defined in Miriam-Webster dictionary as "to fill with resolution or determination, as in, she 'steeled herself to face the…

  13. Metallography of maraging 350 steel

    SciTech Connect

    Hutson, S.M.; Merten, C.W.

    1987-01-01

    A technique for etching maraging 350 steel with Glyceregia is described. Surface activation procedures are integral to this technique. Microstructural features revealed by this technique are compared with those obtained with Kalling's reagent, Fry's reagent, and 5% Nital, three etchants commonly used to reveal microstructures of maraging steels. Features which may be simultaneously revealed using Glyceregia include prior austenite grain boundaries, martensitic structure, precipitates, titanium carbo-nitrides, and reverted austenite. The other etchants examined in this investigation typically reveal only a few of the microstructural features detailed above at any one time. 11 refs., 10 figs., 2 tabs.

  14. Teaching Steel Connections Using an Interactive Virtual Steel Sculpture

    ERIC Educational Resources Information Center

    Moaveni, Saeed; Chou, Karen C.

    2015-01-01

    Steel connections play important roles in the integrity of a structure, and many structural failures are attributed to connection failures. Connections are the glue that holds a structure together. The failures of the Hartford Coliseum in 1977, the Hyatt Regency Hotel in Kansas City in 1980, and the I-35W Bridge in Minneapolis in 2007 are all…

  15. Superhard Nanocrystalline Homometallic Stainless Steel on Steel for Seamless Coatings

    NASA Technical Reports Server (NTRS)

    Tobin, Eric J.; Hafley, R. (Technical Monitor)

    2002-01-01

    The objective of this work is to deposit nanocrystalline stainless steel onto steel substrates (homometallic) for enhanced wear and corrosion resistance. Homometallic coatings provide superior adhesion, and it has been shown that ultrafine-grained materials exhibit the increased hardness and decreased permeability desired for protective coatings. Nanocrystals will be produced by controlling nucleation and growth and use of an ion beam during deposition by e-beam evaporation or sputtering. Phase I is depositing 31 6L nanocrystalline stainless steel onto 31 6L stainless steel substrates. These coatings exhibit hardnesses comparable to those normally obtained for ceramic coatings such ZrO2, and possess the superior adhesion of seamless, homometallic coatings. Hardening the surface with a similar material also enhances adhesion, by avoiding problems associated with thermal and lattice mismatch. So far we have deposited nanocrystalline homometallic 316L stainless steel coatings by varying the ions and the current density of the ion beams. For all deposition conditions we have produced smooth, uniform, superhard coatings. All coatings exhibit hardness of at least 200% harder than that of bulk materials. Our measurements indicate that there is a direct relationship between nanohardness and the current density of the ion beam. Stress measurements indicate that stress in the films is increasingly proportional to current density of the ion beam. TEM, XPS, and XRD results indicate that the coated layers consist of FCC structure nanocrystallites with a dimension of about 10 to 20 nm. The Ni and Mo concentration of these coating are lower than those of bulk 316L but the concentration of Cr is higher.

  16. Preformed posterior stainless steel crowns: an update.

    PubMed

    Croll, T P

    1999-02-01

    For almost 50 years, dentists have used stainless steel crowns for primary and permanent posterior teeth. No other type of restoration offers the convenience, low cost, durability, and reliability of such crowns when interim full-coronal coverage is required. Preformed stainless steel crowns have improved over the years. Better luting cements have been developed and different methods of crown manipulation have evolved. This article reviews stainless steel crown procedures for primary and permanent posterior teeth. Step-by-step placement of a primary molar stainless steel crown is documented and permanent molar stainless steel crown restoration is described. A method for repairing a worn-through crown also is reviewed.

  17. Advanced sheet steels for automotive applications

    NASA Astrophysics Data System (ADS)

    Fekete, James R.; Strugala, Donald C.; Yao, Zhicong

    1992-01-01

    Vacuum degassing has recently been used by sheet steel producers to improve their products' ductility and strength. Carbon contents can be reduced by an order of magnitude to less than 0.0030 wt.%. Through careful alloying and processing, a range of new steel products has been developed for the automotive industry. These products include interstitial-free, deep-drawing-quality steels; formable, high-strength, interstitial-free steels; and bake-hardenable steels. This article summarizes the chemistry and processing needed to produce these products.

  18. Imaging molten steel flow profiles

    NASA Astrophysics Data System (ADS)

    Binns, R.; Lyons, A. R. A.; Peyton, A. J.; Pritchard, W. D. N.

    2001-08-01

    Control of delivery of molten steel in continuous casting is critical in order to ensure stability of the meniscus and satisfactory mould flow patterns, which in turn are determinants of cleanness and surface quality of steel. Considerable effort has been expended over the last ten years on optimizing the design of the metal delivery system, particularly the pouring nozzle, in order to allow the consistent production of high quality steel at a high throughput. This paper looks forward to possible systems that are capable of tomographically imaging the distribution of molten steel flows in these applications. The paper will concentrate on the feasibility of using electromagnetic methods. The paper will present some initial results; an overview of the applied image reconstruction process will also be included. The paper will conclude with a discussion of possible future developments, such as the use of a tomographic or multi-frequency approach, future research on the reconstruction image procedures and the potential for visualization and flow measurement. There is a need for further research in this area and some priority areas for future work will be suggested.

  19. Precision machining of steel decahedrons

    NASA Technical Reports Server (NTRS)

    Abernathy, W. J.; Sealy, J. R.

    1972-01-01

    Production of highly accurate decahedron prisms from hardened stainless steel is discussed. Prism is used to check angular alignment of mounting pads of strapdown inertial guidance system. Accuracies obtainable using recommended process and details of operation are described. Photographic illustration of production device is included.

  20. 60 Years of duplex stainless steel applications

    SciTech Connect

    Olsson, J.; Liljas, M.

    1994-12-31

    In this paper the history of wrought duplex stainless steel development and applications is described. Ferritic-austenitic stainless steels were introduced only a few decades after stainless steels were developed. The paper gives details from the first duplex stainless steels in the 1930`s to the super duplex stainless steel development during the 1980`s. During the years much effort has been devoted to production and welding metallurgy as well as corrosion research of the duplex stainless steels. Therefore, duplex stainless steels are to-day established in a wide product range. Numerous important applications are exemplified. In most cases the selection of a duplex steel has been a result of the combination high strength excellent corrosion resistance. In the pulp and paper industry the most interesting use is as vessel material in digesters. For chemical process industry, the duplex steels are currently used in heat exchangers. The largest application of duplex steels exists in the oil and gas/offshore industry. Hundreds of kms of pipelines are installed and are still being installed. An increased use of duplex steels is foreseen in areas where the strength is of prime importance.

  1. STEFINS: a steel freezing integral simulation program

    SciTech Connect

    Frank, M.V.

    1980-09-01

    STEFINS (STEel Freezing INtegral Simulation) is a computer program for the calculation of the rate of solidification of molten steel on solid steel. Such computations arize when investigating core melt accidents in fast reactors. In principle this problem involves a coupled two-dimensional thermal and hydraulic approach. However, by physically reasonable assumptions a decoupled approach has been developed. The transient solidification of molten steel on a cold wall is solved in the direction normal to the molten steel flow and independent from the solution for the molten steel temperature and Nusselt number along the direction of flow. The solutions to the applicable energy equations have been programmed in cylindrical and slab geometries. Internal gamma heating of steel is included.

  2. Comparative Structural Strength Research of Hardened Carbon Steel and Hot-Rolled Alloy Steel

    NASA Astrophysics Data System (ADS)

    Bogomolov, A. V.; Zhakupov, A. N.; Kanayev, A. T.; Sikach, I. A.; Tugumov, K. K.

    2016-08-01

    Experiments on quantitative evaluation of fatigue strength showed that St5ps and St5sp carbon steels with A400 strength class can be fully applied for erection of constructions and buildings having cyclical loads during operation. Study of corrosion resistance of hardened carbon steel in comparison with hot-rolled alloy steel consists in difference in structures and hence, difference in intensity of electric and chemical processes featuring presence of steel in concrete. Structure of St5sp steel with A400 strength class in surface area has significantly less corrosion rate than ferritic-perlitic structure of 35GS steel with A400 strength class.

  3. Steel project fact sheet: Steel reheating for further processing

    SciTech Connect

    1998-04-01

    Steel reheating is an energy-intensive process requiring uniform temperature distribution within reheating furnaces. Historically, recuperators have ben used to preheat combustion air, thereby conserving energy. More recent innovations include oxygen enrichment and the use of regenerative burners, which provide higher preheat air temperatures than recuperators. These processes have limitations such as equipment deterioration, decreasing energy efficiency over time, high maintenance costs, and increased NO{sub x} emissions with increased air preheat temperature, unless special equipment is used. Praxair, Inc., supplier of oxygen and other industrial gases to the steel industry, proposes to introduce an innovative oxy-fuel burner technology (using 100% oxygen) to the steel reheating industry. Oxy-fuel combustion reduces or eliminates nitrogen in combustion air and substantially reduces waste heat carried out with flue gas. Based on technology currently used in the glass, hazardous waste, and aluminum industries, Praxair has developed and patented low temperature, oxy-fuel burners that can be used in high temperature industrial furnaces where temperature uniformity is critical and extremely low NO{sub x} emissions are desired. The technical goal of the project is to demonstrate the use of oxy-fuel burners in a slab reheat furnace while reducing energy consumption by 45% and NO{sub x} emissions by 90% within the converted furnace zones. Successful implementation of this technology also will eliminate the need to periodically replace recuperators and install NO{sub x} removal equipment.

  4. Bond characteristics of steel fiber and deformed reinforcing steel bar embedded in steel fiber reinforced self-compacting concrete (SFRSCC)

    NASA Astrophysics Data System (ADS)

    Aslani, Farhad; Nejadi, Shami

    2012-09-01

    Steel fiber reinforced self-compacting concrete (SFRSCC) is a relatively new composite material which congregates the benefits of the self-compacting concrete (SCC) technology with the profits derived from the fiber addition to a brittle cementitious matrix. Steel fibers improve many of the properties of SCC elements including tensile strength, ductility, toughness, energy absorption capacity, fracture toughness and cracking. Although the available research regarding the influence of steel fibers on the properties of SFRSCC is limited, this paper investigates the bond characteristics between steel fiber and SCC firstly. Based on the available experimental results, the current analytical steel fiber pullout model (Dubey 1999) is modified by considering the different SCC properties and different fiber types (smooth, hooked) and inclination. In order to take into account the effect of fiber inclination in the pullout model, apparent shear strengths ( τ ( app)) and slip coefficient ( β) are incorporated to express the variation of pullout peak load and the augmentation of peak slip as the inclined angle increases. These variables are expressed as functions of the inclined angle ( ϕ). Furthurmore, steel-concrete composite floors, reinforced concrete floors supported by columns or walls and floors on an elastic foundations belong to the category of structural elements in which the conventional steel reinforcement can be partially replaced by the use of steel fibers. When discussing deformation capacity of structural elements or civil engineering structures manufactured using SFRSCC, one must be able to describe thoroughly both the behavior of the concrete matrix reinforced with steel fibers and the interaction between this composite matrix and discrete steel reinforcement of the conventional type. However, even though the knowledge on bond behavior is essential for evaluating the overall behavior of structural components containing reinforcement and steel fibers

  5. Bond characteristics of steel fiber and deformed reinforcing steel bar embedded in steel fiber reinforced self-compacting concrete (SFRSCC)

    NASA Astrophysics Data System (ADS)

    Aslani, Farhad; Nejadi, Shami

    2012-09-01

    Steel fiber reinforced self-compacting concrete (SFRSCC) is a relatively new composite material which congregates the benefits of the self-compacting concrete (SCC) technology with the profits derived from the fiber addition to a brittle cementitious matrix. Steel fibers improve many of the properties of SCC elements including tensile strength, ductility, toughness, energy absorption capacity, fracture toughness and cracking. Although the available research regarding the influence of steel fibers on the properties of SFRSCC is limited, this paper investigates the bond characteristics between steel fiber and SCC firstly. Based on the available experimental results, the current analytical steel fiber pullout model (Dubey 1999) is modified by considering the different SCC properties and different fiber types (smooth, hooked) and inclination. In order to take into account the effect of fiber inclination in the pullout model, apparent shear strengths (τ (app)) and slip coefficient (β) are incorporated to express the variation of pullout peak load and the augmentation of peak slip as the inclined angle increases. These variables are expressed as functions of the inclined angle (ϕ). Furthurmore, steel-concrete composite floors, reinforced concrete floors supported by columns or walls and floors on an elastic foundations belong to the category of structural elements in which the conventional steel reinforcement can be partially replaced by the use of steel fibers. When discussing deformation capacity of structural elements or civil engineering structures manufactured using SFRSCC, one must be able to describe thoroughly both the behavior of the concrete matrix reinforced with steel fibers and the interaction between this composite matrix and discrete steel reinforcement of the conventional type. However, even though the knowledge on bond behavior is essential for evaluating the overall behavior of structural components containing reinforcement and steel fibers

  6. A mortality study among mild steel and stainless steel welders.

    PubMed

    Moulin, J J; Wild, P; Haguenoer, J M; Faucon, D; De Gaudemaris, R; Mur, J M; Mereau, M; Gary, Y; Toamain, J P; Birembaut, Y

    1993-03-01

    A mortality study was carried out in conjunction with the European mortality study among welders coordinated by the International Agency for Research on Cancer (IARC). The study was aimed at assessing risks for lung cancer in relation to exposure to asbestos, welding fumes containing chromium and nickel, and tobacco smoke. The study included a cohort of 2721 welders and an internal comparison group of 6683 manual workers employed in 13 factories in France. The mortality of the two cohorts was studied from 1975 to 1988 by the historical prospective method. Job histories of welders were traced including welding processes used, metals welded, and proportion of worktime spent in welding. Data on smoking habits were collected from medical records. The observed number of deaths were compared with those expected (standardised mortality ratio (SMR)) based on national rates with adjustments for age, sex, and calendar time. The smoking habits of 87% of the whole study population were known. The distribution of welders and controls according to smoking was not statistically different. The overall mortality was slightly higher for welders (SMR = 1.02, 95% confidence interval (95% CI) 0.89-1.18) than for controls (SMR = 0.91, 95% CI 0.84-0.99). For lung cancer, the SMR was 1.24 (95% CI 0.75-1.94) for welders, whereas the corresponding value was lower for controls (SMR = 0.94, 95% CI 0.68-1.26). The SMR for lung cancer was 1.59 among non-shipyard mild steel welders (95% CI 0.73-3.02). This contrasted with the results for all stainless steel welders (SMR = 0.92, 95% CI 0.19-2.69), and for stainless steel welders predominantly exposed to chromium VI (SMR = 1.03, 95% CI 0.12-3.71). Moreover, SMRs for lung cancer for mild steel welders tended to increase with duration of exposure and time since first exposure, leading to significant excesses for duration > or = 20 years and latency > or = 20 years. Such a pattern was not found for stainless steel welders.

  7. A mortality study among mild steel and stainless steel welders.

    PubMed Central

    Moulin, J J; Wild, P; Haguenoer, J M; Faucon, D; De Gaudemaris, R; Mur, J M; Mereau, M; Gary, Y; Toamain, J P; Birembaut, Y

    1993-01-01

    A mortality study was carried out in conjunction with the European mortality study among welders coordinated by the International Agency for Research on Cancer (IARC). The study was aimed at assessing risks for lung cancer in relation to exposure to asbestos, welding fumes containing chromium and nickel, and tobacco smoke. The study included a cohort of 2721 welders and an internal comparison group of 6683 manual workers employed in 13 factories in France. The mortality of the two cohorts was studied from 1975 to 1988 by the historical prospective method. Job histories of welders were traced including welding processes used, metals welded, and proportion of worktime spent in welding. Data on smoking habits were collected from medical records. The observed number of deaths were compared with those expected (standardised mortality ratio (SMR)) based on national rates with adjustments for age, sex, and calendar time. The smoking habits of 87% of the whole study population were known. The distribution of welders and controls according to smoking was not statistically different. The overall mortality was slightly higher for welders (SMR = 1.02, 95% confidence interval (95% CI) 0.89-1.18) than for controls (SMR = 0.91, 95% CI 0.84-0.99). For lung cancer, the SMR was 1.24 (95% CI 0.75-1.94) for welders, whereas the corresponding value was lower for controls (SMR = 0.94, 95% CI 0.68-1.26). The SMR for lung cancer was 1.59 among non-shipyard mild steel welders (95% CI 0.73-3.02). This contrasted with the results for all stainless steel welders (SMR = 0.92, 95% CI 0.19-2.69), and for stainless steel welders predominantly exposed to chromium VI (SMR = 1.03, 95% CI 0.12-3.71). Moreover, SMRs for lung cancer for mild steel welders tended to increase with duration of exposure and time since first exposure, leading to significant excesses for duration > or = 20 years and latency > or = 20 years. Such a pattern was not found for stainless steel welders. PMID:8457490

  8. Longer Life for Steel Structures

    NASA Technical Reports Server (NTRS)

    1990-01-01

    IC 531 is a coating manufactured and marketed by Inorganic Coatings, Inc. The coating was developed by Goddard to protect structures at Kennedy Space Center. It is a high ratio potassium silicate formula. The coating is water based, nontoxic, and nonflammable. It generates no volatile organic compounds nor hazardous chemical waste, and bonds to steel in 30 minutes. At the present time, no one can say for sure how long IC 531's effective lifetime is. Some of the original Goddard test applications of 1976 are still going strong after lengthy exposure to the Sun, salt and moisture. Says IC in company literature: 'IC 531 offers virtually permanent protection for steel. We predict it will protect structures for well beyond 25 years. If necessary, it is infinitely maintainable; if damaged, it can easily be touched up with more IC 531.'

  9. Steel Industry Energy Bandwidth Study

    SciTech Connect

    none,

    2004-10-01

    ITP conducted a study on energy use and potential savings, or "bandwidth" study, in major steelmaking processes. Intended to provide a realistic estimate of the potential amount of energy that can be saved in an industrial process, the "bandwidth" refers to the difference between the amount of energy that would be consumed in a process using commercially available technology versus the minimum amount of energy needed to achieve those same results based on the 2nd law of thermodynamics. The Steel Industry Energy Bandwidth Study (PDF 133 KB) also estimates steel industry energy use in the year 2010, and uses that value as a basis for comparison against the minimum requirements. This energy savings opportunity for 2010 will aid focus on longer term R&D.

  10. Light microscopy of carbon steels

    SciTech Connect

    Samuels, L.E.

    1998-12-31

    Containing over 1,200 representative micrographs and the information and explanatory text that makes them really useful: composition, condition, etchant, and magnification, and more than 100 graphs and tables, this how to book not only gives everyday working examples, but also discusses the relationship between the constitution, metallurgy, and microstructure of various carbon steel products. Written by a renowned expert in metallography, this definitive work is a must for all those working in this area. Contents include: nomenclature of phases and constituents; phase transformations; low-carbon irons and steels; annealing and normalizing; spheroidization and graphitization; austenitization; transformation of austenite; tempering of martensite; welding; surface oxidation, decarburation; and oxidation scaling; glossary of terms; etching methods; conversion tables.

  11. Welding of high chromium steels

    NASA Technical Reports Server (NTRS)

    Miller, W B

    1928-01-01

    A brief description is given of different groups of high chromium steels (rustless iron and stainless steels) according to their composition and more generally accepted names. The welding procedure for a given group will be much the same regardless of the slight variations in chemical composition which may exist within a certain group. Information is given for the tensile properties (yield point and ultimate strength) of metal sheets and welds before and after annealing on coupons one and one-half inches wide. Since welds in rustless iron containing 16 to 18 percent chromium and 7 to 12 percent nickel show the best combination of strength and ductility in the 'as welded' or annealed condition, it is considered the best alloy to use for welded construction.

  12. Shock Hugoniot of 1215 steel

    NASA Astrophysics Data System (ADS)

    Brar, N. S.; Rosenberg, Z.

    1996-05-01

    1215 steel is almost pure iron with 0.1 percent or less carbon. Information pertaining to deformation of this material under shock loading is useful to simulate penetration of projectiles of different shapes, such as fragments or rods, in propellants storage containments made from almost pure iron. In this paper we present the dynamic response of 1215 steel to shock wave loading to 30 GPa. Manganin gauges were used to record the stress wave profiles in these experiments. The Hugoniot data in the stress-particle velocity plane was obtained to 30 GPa. Hugoniot elastic limit was found to be 1.37±0.05 GPa. Phase transformation (α-ɛ) takes place at about 13.2±0.2 GPa, which agrees with the value determined by Barker and Hollenbach using VISAR. Hugoniot does not show any softening at stresses below 13 GPa.

  13. Steel Industry Marginal Opportunity Analysis

    SciTech Connect

    none,

    2005-09-01

    The Steel Industry Marginal Opportunity Analysis (PDF 347 KB) identifies opportunities for developing advanced technologies and estimates both the necessary funding and the potential payoff. This analysis determines what portion of the energy bandwidth can be captured through the adoption of state-of-the-art technology and practices. R&D opportunities for addressing the remainder of the bandwidth are characterized and plotted on a marginal opportunity curve.

  14. A study of Damascus steel

    SciTech Connect

    Berge, P.

    1995-02-16

    The Damascus sword has been an article of fascination for many years to blade collectors and metallurgists alike. The blades were given their name by Europeans who encountered these blades which originated from Damascus, Syria. They are best known for the appearance of the blade face. Genuine Damascus blades show swirling patterns of alternating light and dark regions which are due to the microstructure of the steel. The microstructure consists of arrays of well rounded cementite patterns in a matrix of either pearlite, bainite, or martensite. When this structure is etched the matrix will turn dark leaving the cementite particles light. Although many blades were produced over the centuries, while some of the process is known the making of a genuine Damascus blade today is generally considered a lost art. Many scientists have studied the subject in an attempt to understand the complex process by which the clustered arrays of cementite particles develop in the steel blades. The most prominent theories to date are presented in the General Introduction to this thesis. The thesis is divided into four main parts. In the first part, four proposed mechanisms of cementite cluster sheet formation as they relate to the banding theory are introduced. Experiments to investigate these mechanisms are presented. In Part II, collaborative research focused on the methodology of the reconstructed process for making Damascus steel is presented. In the third part, a study into the graphitization of the reconstructed blades is presented. In Part IV, experimental attempts at producing Damascus steel ingots in the laboratory are presented.

  15. Steel Collet For Welding Electrodes

    NASA Technical Reports Server (NTRS)

    Gilbert, Jeffrey L.; Gutow, David A.; Burley, Richard K.; Fogul, Irving

    1992-01-01

    Improved steel collet holds electrode for tungsten inert-gas welding but allows quick and easy replacement. Also ensures reliable arc starting. Slip-on compression ring compresses tapered section of body of collet around inner end of welding electrode. Collet mounted in receptacle below stack of lenses and filters in coaxial-vision welding torch. Blind hole in collet protects outermost lens from damage by electrode.

  16. Nano-composite stainless steel

    DOEpatents

    Dehoff, Ryan R.; Blue, Craig A.; Peter, William H.; Chen, Wei; Aprigliano, Louis F.

    2015-07-14

    A composite stainless steel composition is composed essentially of, in terms of wt. % ranges: 25 to 28 Cr; 11 to 13 Ni; 7 to 8 W; 3.5 to 4 Mo; 3 to 3.5 B; 2 to 2.5 Mn; 1 to 1.5 Si; 0.3 to 1.7 C; up to 2 O; balance Fe. The composition has an austenitic matrix phase and a particulate, crystalline dispersed phase.

  17. Nickel: makes stainless steel strong

    USGS Publications Warehouse

    Boland, Maeve A.

    2012-01-01

    Nickel is a silvery-white metal that is used mainly to make stainless steel and other alloys stronger and better able to withstand extreme temperatures and corrosive environments. Nickel was first identified as a unique element in 1751 by Baron Axel Fredrik Cronstedt, a Swedish mineralogist and chemist. He originally called the element kupfernickel because it was found in rock that looked like copper (kupfer) ore and because miners thought that "bad spirits" (nickel) in the rock were making it difficult for them to extract copper from it. Approximately 80 percent of the primary (not recycled) nickel consumed in the United States in 2011 was used in alloys, such as stainless steel and superalloys. Because nickel increases an alloy's resistance to corrosion and its ability to withstand extreme temperatures, equipment and parts made of nickel-bearing alloys are often used in harsh environments, such as those in chemical plants, petroleum refineries, jet engines, power generation facilities, and offshore installations. Medical equipment, cookware, and cutlery are often made of stainless steel because it is easy to clean and sterilize. All U.S. circulating coins except the penny are made of alloys that contain nickel. Nickel alloys are increasingly being used in making rechargeable batteries for portable computers, power tools, and hybrid and electric vehicles. Nickel is also plated onto such items as bathroom fixtures to reduce corrosion and provide an attractive finish.

  18. Utilization of structural steel in buildings.

    PubMed

    Moynihan, Muiris C; Allwood, Julian M

    2014-08-01

    Over one-quarter of steel produced annually is used in the construction of buildings. Making this steel causes carbon dioxide emissions, which climate change experts recommend be reduced by half in the next 37 years. One option to achieve this is to design and build more efficiently, still delivering the same service from buildings but using less steel to do so. To estimate how much steel could be saved from this option, 23 steel-framed building designs are studied, sourced from leading UK engineering firms. The utilization of each beam is found and buildings are analysed to find patterns. The results for over 10 000 beams show that average utilization is below 50% of their capacity. The primary reason for this low value is 'rationalization'-providing extra material to reduce labour costs. By designing for minimum material rather than minimum cost, steel use in buildings could be drastically reduced, leading to an equivalent reduction in 'embodied' carbon emissions.

  19. A Method for Imaging Steel Bars Behind a Ferrous Steel Boundary

    NASA Astrophysics Data System (ADS)

    Fernandes, B.; Miller, G.; Zaid, M.; Gaydecki, P.

    2006-03-01

    A system for detecting steel objects behind ferrous steel boundaries is described. It may be used to image steel reinforcing bars in concrete, where a steel sheet exists between the bars and the surface. The sensor comprises a transmitter, receiver and a dummy coil, which cancels cross-talk and enhances the signal from the bars. It is possible to penetrate a 2mm thick sheet at 125 Hz and image 16 mm diameter bars placed underneath.

  20. Evaluation of stress corrosion cracking of irradiated 304L stainless steel in PWR environment using heavy ion irradiation

    NASA Astrophysics Data System (ADS)

    Gupta, J.; Hure, J.; Tanguy, B.; Laffont, L.; Lafont, M.-C.; Andrieu, E.

    2016-08-01

    IASCC has been a major concern regarding the structural and functional integrity of core internals of PWR's, especially baffle-to-former bolts. Despite numerous studies over the past few decades, additional evaluation of the parameters influencing IASCC is still needed for an accurate understanding and modeling of this phenomenon. In this study, Fe irradiation at 450 °C was used to study the cracking susceptibility of 304 L austenitic stainless steel. After 10 MeV Fe irradiation to 5 dpa, irradiation-induced damage in the microstructure was characterized and quantified along with nano-hardness measurements. After 4% plastic strain in a PWR environment, quantitative information on the degree of strain localization, as determined by slip-line spacing, was obtained using SEM. Fe-irradiated material strained to 4% in a PWR environment exhibited crack initiation sites that were similar to those that occur in neutron- and proton-irradiated materials, which suggests that Fe irradiation may be a representative means for studying IASCC susceptibility. Fe-irradiated material subjected to 4% plastic strain in an inert argon environment did not exhibit any cracking, which suggests that localized deformation is not in itself sufficient for initiating cracking for the irradiation conditions used in this study.

  1. Identification of RFLP markers closely linked to the bolting gene B and their significance for the study of the annual habit in beets (Beta vulgaris L.).

    PubMed

    Boudry, P; Wieber, R; Saumitou-Laprade, P; Pillen, K; Van Dijk, H; Jung, C

    1994-08-01

    The annual habit in beet is due to complete or partial absence of the vernalization requirement and can cause severe problems in the beet crop. The absolute vernalization requirement in beet is controlled by a major geneB (bolting), known to be linked to the geneR (red hypocotyl color), in linkage group I. Segregation for theB andR genes was studied in several beet progenies. Penetrance of the annual habit inBb genotypes was affected by both environmental and genetic factors. The precise location in linkage group I of the major geneB was found by restriction fragment length polymorphism (RFLP) analysis in a back-cross progeny exhibiting partial penetrance of the annual habit. The linkage value betweenB andR was in good accordance with previous estimations. Use of the closest RFLP marker (pKP591: 3.8 recombination units) allowed us to estimate the penetrance of the annual habit in this back-cross as 0.62. Evidence of pseudo-compatibility was found in the wild coastal beet (Beta vulgaris sspmaritima) used as the mother plant of the back-cross: the selfing rate was estimated as 7%.

  2. The Structure and Mechanical Properties of Bridge Steel Weldings With Glass-Steel Liners

    NASA Astrophysics Data System (ADS)

    Muzalev, V. N.; Semukhin, B. S.; Danilov, V. I.

    2016-04-01

    A new technology is developed for welding multi-span bridge constructions. The mechanical properties and structure of the low-carbon bridge steel welds have been studied. The welding parameters and application of steel-glass liners provide for long-term service of steel constructions in conformity with the welding industry specifications.

  3. Welding Metallurgy and Weldability of Stainless Steels

    NASA Astrophysics Data System (ADS)

    Lippold, John C.; Kotecki, Damian J.

    2005-03-01

    Welding Metallurgy and Weldability of Stainless Steels, the first book in over twenty years to address welding metallurgy and weldability issues associated with stainless steel, offers the most up-to-date and comprehensive treatment of these topics currently available. The authors emphasize fundamental metallurgical principles governing microstructure evolution and property development of stainless steels, including martensistic, ferric, austenitic, duplex, and precipitation hardening grades. They present a logical and well-organized look at the history, evolution, and primary uses of each stainless steel, including detailed descriptions of the associated weldability issues.

  4. 37. Photocopy of photograph. STEEL PLANT, OPEN HOUSE INSIDE PLANT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    37. Photocopy of photograph. STEEL PLANT, OPEN HOUSE INSIDE PLANT AT TIME OF ITS OPENING, 1910. (From the Bethlehem Steel Corporation Collection, Seattle, WA) - Irondale Iron & Steel Plant, Port Townsend, Jefferson County, WA

  5. 30. Photocopy of photograph. STEEL PLANT, OPEN HEARTH FURNACE CHARGING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    30. Photocopy of photograph. STEEL PLANT, OPEN HEARTH FURNACE CHARGING CREW, 1910. (From the Bethlehem Steel Corporation Colletion, Seattle, WA) - Irondale Iron & Steel Plant, Port Townsend, Jefferson County, WA

  6. North and west facades of crucible steel building; looking southeast ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    North and west facades of crucible steel building; looking southeast - Bethlehem Steel Corporation, South Bethlehem Works, Crucible Steel Plant, Along Lehigh River, North of Fourth Street, West of Minsi Trail Bridge, Bethlehem, Northampton County, PA

  7. Experimental, numerical, and analytical studies on the seismic response of steel-plate concrete (SC) composite shear walls

    NASA Astrophysics Data System (ADS)

    Epackachi, Siamak

    The seismic performance of rectangular steel-plate concrete (SC) composite shear walls is assessed for application to buildings and mission-critical infrastructure. The SC walls considered in this study were composed of two steel faceplates and infill concrete. The steel faceplates were connected together and to the infill concrete using tie rods and headed studs, respectively. The research focused on the in-plane behavior of flexure- and flexure-shear-critical SC walls. An experimental program was executed in the NEES laboratory at the University at Buffalo and was followed by numerical and analytical studies. In the experimental program, four large-size specimens were tested under displacement-controlled cyclic loading. The design variables considered in the testing program included wall thickness, reinforcement ratio, and slenderness ratio. The aspect ratio (height-to-length) of the four walls was 1.0. Each SC wall was installed on top of a re-usable foundation block. A bolted baseplate to RC foundation connection was used for all four walls. The walls were identified to be flexure- and flexure-shear critical. The progression of damage in the four walls was identical, namely, cracking and crushing of the infill concrete at the toes of the walls, outward buckling and yielding of the steel faceplates near the base of the wall, and tearing of the faceplates at their junctions with the baseplate. A robust finite element model was developed in LS-DYNA for nonlinear cyclic analysis of the flexure- and flexure-shear-critical SC walls. The DYNA model was validated using the results of the cyclic tests of the four SC walls. The validated and benchmarked models were then used to conduct a parametric study, which investigated the effects of wall aspect ratio, reinforcement ratio, wall thickness, and uniaxial concrete compressive strength on the in-plane response of SC walls. Simplified analytical models, suitable for preliminary analysis and design of SC walls, were

  8. 77 FR 30589 - SteelRiver Infrastructure Partners LP, SteelRiver Infrastructure Associates LLC, SteelRiver...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-23

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF TRANSPORTATION Surface Transportation Board SteelRiver Infrastructure Partners LP, SteelRiver Infrastructure Associates..., referring to Docket No. FD 35622 must be filed with the Surface Transportation Board, 395 E Street...

  9. Corrosion behaviour of galvanized steel and electroplating steel in aqueous solution: AC impedance study and XPS

    NASA Astrophysics Data System (ADS)

    Lebrini, M.; Fontaine, G.; Gengembre, L.; Traisnel, M.; Lerasle, O.; Genet, N.

    2008-08-01

    The efficiency of a new triazole derivative, namely, 2-{(2-hydroxyethyl)[(4-methyl-1 H-1,2,3-benzotriazol-1-yl)methyl]amino}ethanol (TTA) has been studied for corrosion inhibition of galvanized steel and electroplating steel in aqueous solution. Corrosion inhibition was studied using electrochemical impedance spectroscopy (EIS). These studies have shown that TTA was a very good inhibitor. Data obtained from EIS show a frequency distribution and therefore a modelling element with frequency dispersion behaviour, a constant phase element (CPE) has been used. The corrosion behaviour of galvanized steel and electroplating steel in aqueous solution was also investigated in the presence of 4-methyl-1 H-benzotriazole (TTA unsubstituted) by EIS. These studies have shown that the ability of the molecule to adsorb on the steel surface was dependent on the group in triazole ring substituent. X-ray photoelectron spectroscopy surface analysis with TTA shows that it chemisorbed on surface of galvanized steel and electroplating steel.

  10. Corrosion Behavior of IF Steel in Various Media and Its Comparison with Mild Steel

    NASA Astrophysics Data System (ADS)

    Singh, G. P.; Moon, A. P.; Sengupta, S.; Deo, G.; Sangal, S.; Mondal, K.

    2015-05-01

    The present work discusses corrosion behavior of an interstitial-free (IF) steel in 0.6 M NaCl, 1 M NaOH, and 1 M HCl solutions, and its comparison with mild steel (MS). Dynamics polarization and AC Impedance Spectroscopy explain different polarization behaviors of the steel samples. All the steels were exposed to open atmosphere for 100 days, and to 0.6 M NaCl salt fog for 30 days. Scanning electron microscopy, x-ray diffraction, and Raman and Fourier Transformed Infrared Spectroscopy were used to characterize microstructure of the steels, rust constituents, and morphologies. Corrosion behavior of the steels has close relation with the morphology and constituents of the rusts. It has been observed that the corrosion in the IF and MS steels is uniform in nature.

  11. Evaluation of Steel Cleanliness in a Steel Deoxidized Using Al

    NASA Astrophysics Data System (ADS)

    Castro-Cedeño, Edgar-Ivan; Herrera-Trejo, Martín; Castro-Román, Manuel; Castro-Uresti, Fabián; López-Cornejo, Monserrat

    2016-06-01

    The effect of magnesium in the aluminum used as a deoxidizer on the cleanliness of steel was studied throughout a steelmaking route for the production of thin slabs. Two deoxidizers with different Mg contents were used. The Mg content of a "typical" deoxidizer was ~0.5 wt pct Mg, whereas that for an alternative deoxidizer was ~2 wt pct Mg. The inclusion population at different stages of the steelmaking process was characterized in terms of chemical composition, number, and size distribution. The inclusion modification path shows that the solid Al2O3 and Al2O3-MgO inclusions formed in the early stage of the steel ladle treatment are modified into Al2O3-MgO-CaO liquid and MgO-Al2O3-liquid inclusions. Although some slight differences were observed in the ladle furnace samples, the chemical composition of inclusions was similar in the samples taken at the mold of the continuous casting, regardless of the deoxidizer used. Gumbel, generalized extreme value (GEV), and generalized Pareto (GP) distributions were used for the description of the size distribution. The GEV and GP distributions resulted in proper distributions to describe the evolution of size distribution throughout the steelmaking process. Furthermore, no statistically significant differences between inclusion size distributions resulting from the use of either deoxidizer were found.

  12. [Initial stages of steel biocorrosion].

    PubMed

    Zhigletsova, S K; Rodin, V B; Kobelev, V S; Aleksandrova, N V; Rasulova, G E; Kholodenko, V P

    2000-01-01

    Initial stages of corrosion of mild steel induced by Klebsiela rhinoscleromatis BO2 were studied in various media. The effect of the microorganism was detected 8-10 h after inoculation. The number of viable cells were virtually unchanged within one month in all media, but the corrosive activity of the strain decreased. The corrosive activity of microorganisms can be determined by spectrophotometry even only after incubation for 24 h. At a low level of organic substrate, even strong colonization with microorganisms does not inevitably result in a significant damage to metals.

  13. Chromizing of 3Cr Steel

    SciTech Connect

    Ravi, Vilupanur; Harrison, Bradley; Koch, Jordan; Ly, Alexander; Schissler, Andrew; Pint, Bruce A; Haynes, James A

    2011-01-01

    Grade 315 steel (Fe-2.9 Cr-1.7 W-0.7 Mo-0.3 Mn-0.3 Si-0.2 V-0.1 Ni-0.13 C-0.01 N) was chromized by the halide-activated pack cementation (HAPC) process. Key process parameters, i.e., coating temperatures and pack compositions, were investigated. Ammonium chloride-activated packs in the 700-1000 C range produced coatings nominally in the 1-8 {micro}m range, as determined by optical and scanning electron microscopy (SEM). Coatings applied in the 900-1000 C temperature range resulted in Cr-rich coatings. The predominant phase in the coating was identified as Cr23C6 by X-ray diffraction. In addition, the presence of chromium nitride, Cr2N, was observed in the coating. The power generation industry is faced with an ever-increasing demand for energy while simultaneously having to reduce carbon emissions. These goals can be facilitated by increasing plant efficiency through the use of higher operating temperatures and pressures. Traditional construction materials, e.g., the ferritic Grade 22 high strength low alloy steel, are limited to operations below {approx} 550 C. Therefore, new materials are required for future plants designed to operate up to 650 C and possibly higher. These new materials need to have improved tensile strength, ductility, toughness, corrosion resistance, and creep properties at elevated temperatures. Oak Ridge National Laboratory (ORNL) is investigating the oxidation and creep behavior of various coatings on Grade 315 steel (Fe-2.9 Cr-1.7 W-0.7 Mo-0.3 Mn-0.3 Si-0.2 V-0.1 Ni-0.13 C-0.01 N), a super-bainitic steel developed for superior creep properties. Thin, chemical vapor-deposited (CVD) aluminide coatings were used to compensate for the reduced corrosion and oxidation resistance that resulted from the low chromium content of the alloy. However, the aluminized Grade 315 alloys performed less-than-favorably under conditions relevant to fossil boilers, leading to the conclusion that higher chromium contents are required for the formation of

  14. Weldability charts for constructional steels

    NASA Astrophysics Data System (ADS)

    Ion, J. C.; Ashby, M. F.

    2012-02-01

    The weldability of materials is still a poorly understood concept; a quantitative assessment remains elusive. The variables associated with welding are reduced here into two groups - processing parameters and material properties - from which two characteristic indices are defined and used as the basis of weldability charts. For the case of constructional steels, a carbon equivalent characterises both heat affected zone hardenability and the maximum hardness developed after solid state phase transformations. The welding process is characterised by its energy input. A mathematical model is used to establish relationships between the indices, which are displayed on charts as contours of microstructure and hardness.

  15. Help for the Steel Industry

    NASA Technical Reports Server (NTRS)

    1991-01-01

    A collaboration between NASA Lewis Research Center (LRC) and Gladwin Engineering resulted in the adaptation of aerospace high temperature metal technology to the continuous casting of steel. The continuous process is more efficient because it takes less time and labor. A high temperature material, once used on the X-15 research plane, was applied to metal rollers by a LRC developed spraying technique. Lewis Research Center also supplied mold prototype of metal composites, reducing erosion and promoting thermal conductivity. Rollers that previously cracked due to thermal fatigue, lasted longer. Gladwin's sales have increased, and additional NASA-developed innovations are anticipated.

  16. METHOD FOR JOINING ALUMINUM TO STAINLESS STEEL

    DOEpatents

    Lemon, L.C.

    1960-05-24

    Aluminum may be joined to stainless steel without the use of flux by tinning the aluminum with a tin solder containing 1% silver and 1% lead, tinning the stainless steel with a 50% lead 50% tin solder, and then sweating the tinned surfaces together.

  17. Chem I Supplement: Chemistry of Steel Making.

    ERIC Educational Resources Information Center

    Sellers, Neal

    1980-01-01

    Provides information about the chemistry of steel making applicable to teaching secondary school science. Generalized chemical reactions describe the manufacture of steel from iron ore. Also discussed are raw materials, processing choices, and how various furnaces (blast, direct reduction, open hearth, basic oxygen, electric) work. (CS)

  18. Steel powder with a metastable austenite structure

    SciTech Connect

    Antsiferov, V.N.; Maslennikov, N.; Shatsov, A.A.

    1994-09-01

    The effect of technological parameters of fabrication on wear resistance and phase transformations in the surface layer of a chromium-nickel steel is studied. A statistical model is proposed for prediction of the content inhomogeneity of the steel. Enhanced abrasive wear resistance is attained by appropriate transformations in the surface layer.

  19. Forming "dynamic" membranes on stainless steel

    NASA Technical Reports Server (NTRS)

    Brandon, C. A.; Gaddis, J. L.

    1979-01-01

    "Dynamic" zirconium polyacrylic membrane is formed directly on stainless steel substrate without excessive corrosion of steel. Membrane is potentially useful in removal of contaminated chemicals from solution through reversed osmosis. Application includes use in filtration and desalination equipment, and in textile industry for separation of dyes from aqueous solvents.

  20. Instabilities in stabilized austenitic stainless steels

    NASA Astrophysics Data System (ADS)

    Ayer, Raghavan; Klein, C. F.; Marzinsky, C. N.

    1992-09-01

    The effect of aging on the precipitation of grain boundary phases in three austenitic stainless steels (AISI 347, 347AP, and an experimental steel stabilized with hafnium) was investigated. Aging was performed both on bulk steels as well as on samples which were subjected to a thermal treatment to simulate the coarse grain region of the heat affected zone (HAZ) during welding. Aging of the bulk steels at 866 K for 8000 hours resulted in the precipitation of Cr23C6 carbides, σ, and Fe2Nb phases; the propensity for precipitation was least for the hafnium-stabilized steel. Weld simulation of the HAZ resulted in dissolution of the phases present in the as-received 347 and 347AP steels, leading to grain coarsening. Subsequent aging caused extensive grain boundary Cr23C6 carbides and inhomogeneous matrix precipitation. In addition, steel 347AP formed a precipitate free zone (PFZ) along the grain boundaries. The steel containing hafnium showed the best microstructural stability to aging and welding.

  1. A recycling process for dezincing steel scrap

    SciTech Connect

    Dudek, F.J.; Daniels, E.J. ); Morgan, W.A.; Kellner, A.W.; Harrison, J. )

    1992-01-01

    In response to the several-fold increase in consumption of galvanized steel in the last decade and the problems associated with refurnacing larger quantities of galvanized steel scrap, a process is being developed to separate and recover the steel and zinc from galvanized ferrous scrap. The zinc is dissolved from the scrap in hot caustic using anodic assistance and is electrowon as dendritic powder. The process is effective for zinc, lead, aluminum, and cadmium removal on loose and baled scrap and on all types of galvanized steel. The process has been pilot tested for batch treatment of 1,000 tons of mostly baled scrap. A pilot plant to continuously treat loose scrap is under construction. Use of degalvanized steel scrap decreases raw materials and environmental compliance costs to steel- and iron-makers, may enable integrated steel producers to recycle furnace dusts to the sinter plant, and may enable EAF production of flat products without use of DRI or pig iron. Recycling the components of galvanized steel scrap saves primary energy, decreases zinc imports, and adds value to the scrap.

  2. Mineral resource of the month: steel

    USGS Publications Warehouse

    Fenton, Michael D.

    2007-01-01

    About 96 million metric tons of steel was produced in the United States last year — more than any other metal. And the $3.46 billion of iron and steel scrap exported was also the highest of any metal scrap export, helping to reduce the U.S. trade deficit.

  3. Ellie Mannette: Master of the Steel Drum.

    ERIC Educational Resources Information Center

    Svaline, J. Marc

    2001-01-01

    Presents an interview with Elliot ("Ellie") Mannette who has played a major role in the development and application of steel drums. States that he has spent most of his life designing and teaching the steel drums. Covers interview topics and background information on Mannette. (CMK)

  4. African Drum and Steel Pan Ensembles.

    ERIC Educational Resources Information Center

    Sunkett, Mark E.

    2000-01-01

    Discusses how to develop both African drum and steel pan ensembles providing information on teacher preparation, instrument choice, beginning the ensemble, and lesson planning. Includes additional information for the drum ensembles. Lists references and instructional materials, sources of drums and pans, and common note layout/range for steel pan…

  5. A recycling process for dezincing steel scrap

    SciTech Connect

    Dudek, F.J.; Daniels, E.J.; Morgan, W.A.; Kellner, A.W.; Harrison, J.

    1992-08-01

    In response to the several-fold increase in consumption of galvanized steel in the last decade and the problems associated with refurnacing larger quantities of galvanized steel scrap, a process is being developed to separate and recover the steel and zinc from galvanized ferrous scrap. The zinc is dissolved from the scrap in hot caustic using anodic assistance and is electrowon as dendritic powder. The process is effective for zinc, lead, aluminum, and cadmium removal on loose and baled scrap and on all types of galvanized steel. The process has been pilot tested for batch treatment of 1,000 tons of mostly baled scrap. A pilot plant to continuously treat loose scrap is under construction. Use of degalvanized steel scrap decreases raw materials and environmental compliance costs to steel- and iron-makers, may enable integrated steel producers to recycle furnace dusts to the sinter plant, and may enable EAF production of flat products without use of DRI or pig iron. Recycling the components of galvanized steel scrap saves primary energy, decreases zinc imports, and adds value to the scrap.

  6. Stainless steel 4003 in the transportation industry

    SciTech Connect

    Kovacs, H.; Stoeckl, M.

    1998-12-31

    The world today sees a dramatic increase in the number of people and the quantities of articles and products which are to be transported. This results in an ever-increasing demand in the steels used in the transportation industry. Key factors are environmental regulations, safety, and life expectancy and product cost in determining which types steel to use. Especially the ferritic 12% chromium stainless steels has seen a significant development and usage in recent years. Compared to typical carbon steels high strength/low alloy steels and structural steels the 12% chromium steels offers improvement in corrosion and wear resistance and weldability outlining advantages in light weight construction and an overall saving. The paper presents the chemical composition and mechanical properties of grade 4003 which is increasingly used worldwide in areas of public transportation, rail transportation, mining industry and sugar industry, among others. The impact of corrosion and abrasion of this stainless steel versus the standard carbon grades and cost efficiency are discussed.

  7. Method for welding chromium molybdenum steels

    DOEpatents

    Sikka, Vinod K.

    1986-01-01

    Chromium-molybdenum steels exhibit a weakening after welding in an area adjacent to the weld. This invention is an improved method for welding to eliminate the weakness by subjecting normalized steel to a partial temper prior to welding and subsequently fully tempering the welded article for optimum strength and ductility.

  8. Low Mn alloy steel for cryogenic service

    DOEpatents

    Morris, J.W. Jr.; Niikura, M.

    A ferritic cryogenic steel which has a relatively low (about 4 to 6%) manganese content and which has been made suitable for use at cryogenic temperatures by a thermal cycling treatment followed by a final tempering. The steel includes 4 to 6% manganese, 0.02 to 0.06% carbon, 0.1 to 0.4% molybdenum and 0 to 3% nickel.

  9. Monitoring of weathering steel structures. The induction ultrasonic thickness testers

    NASA Astrophysics Data System (ADS)

    McKenzie, M.

    Long term corrosion tests carried out in the UK show that weathering steels continue to corrode at a finite rate. It is therefore necessary to use thicker steel and to monitor the corrosion. An ultrasonic instrument to measure residual steel thickness was assessed. This measures steel thickness through a rust layer, requires no couplant to transmit the ultrasound into the steel and gives only the steel thickness not the thickness of the steel plus a layer of rust. This instrument provides a suitable method of measuring the residual steel thickness on weathering steel structures where corrosion has been generally uniform. However, the instrument can give no information on localized roughness or pitting of the underlying steel surface and it would seem worthwhile to include test specimens in any monitoring scheme so that the surface condition of the steel can be assessed.

  10. The comparison of frictional resistance in titanium, self-ligating stainless steel, and stainless steel brackets using stainless steel and TMA archwires: An in vitro study

    PubMed Central

    Khalid, Syed Altaf; Kumar, Vadivel; Jayaram, Prithviraj

    2012-01-01

    Aim: The aim of the study was to compare the frictional resistance of titanium, self-ligating stainless steel, and conventional stainless steel brackets, using stainless steel and titanium molybdenum alloy (TMA) archwires. Materials and Methods: We compared the frictional resistance in 0.018 slot and 0.022 slot of the three brackets – titanium, self-ligating stainless steel, and conventional stainless steel – using stainless steel archwires and TMA archwires. An in vitro study of simulated canine retraction was undertaken to evaluate the difference in frictional resistance between titanium, self-ligating stainless steel, and stainless steel brackets, using stainless steel and TMA archwires. Results and Conclusion: We compared the frictional resistance of titanium, self-ligating stainless steel, and conventional stainless steel brackets, using stainless steel and TMA archwires, with the help of Instron Universal Testing Machine. One-way analysis of variance (ANOVA), Student's “t” test, and post hoc multiple range test at level of <0.05 showed statistically significant difference in the mean values of all groups. Results demonstrated that the titanium, self-ligating stainless steel, and stainless steel brackets of 0.018-inch and 0.022-inch slot had no significant variations in frictional résistance. The self-ligating bracket with TMA archwires showed relatively less frictional resistance compared with the other groups. The titanium bracket with TMA archwires showed relatively less frictional resistance compared with the stainless steel brackets. PMID:23066253

  11. A modification of 4330 alloy steel

    SciTech Connect

    Gogolewski, R.; Cunningham, B.J. ); Gentile, R.; Fleming, S. )

    1990-08-01

    We have developed a modification of 4330 alloy steel which does not have an exact equivalent expressed in any standard specification. When we compare the ballistic performance of our modified cast steel in thicknesses of about 120 mm with that of stacked, 24 mm thick rolled 4340 alloy steel plates of comparable hardness and the same total thickness, we do not find a significant difference in terminal ballistic performance against either heavy metal kinetic energy penetrators or precision shaped charges. This result is surprising in relation to contemporary experience in which cast steel has been found to be ballistically inferior to rolled steel against either kinetic energy projectiles or shaped charge warheads. 1 ref., 9 figs.

  12. Advances in crosswell electromagnetics steel cased boreholes

    SciTech Connect

    Harben, P E; Kirkendall, B A; Lewis, J P

    1999-03-01

    The Crosswell electromagnetic (EM) induction technique ideally measures the resistivity distribution between boreholes which may often be cased with carbon steel. Quantification of the effect of such steel casing on the induced field is the most significant limitation of the technique. Recent data acquired at a site in Richmond, California quantify the effect of steel casing on induction measurements and demonstrate this effect to be separable. This unique site contains adjacent steel and plastic wells in which frequency soundings demonstrate low spectrum (1.0 - 50 Hz) measurements an effective means of isolating the casing response from, the formation response. It is also shown that the steel casing effect on the induction coil is highly localized, and limited to less than 0.30 meters above and below the coil.

  13. Aerosol filtration with steel fiber filters

    NASA Astrophysics Data System (ADS)

    Bergman, W.; Wilson, K.; Larsen, G.; Lopez, R.

    1993-04-01

    An experimental study has been conducted of aerosol penetration through a new high efficiency steel fiber filter and filter media that was developed in cooperation with Pall Corporation. Previous studies have shown that sintered steel fiber media have significant improvements in higher filter efficiency and lower pressure drop than the previous steel filter technology based on sintered powder metal media. In the present study, measurements were made of the penetration of dioctyl sebacate (DOS) aerosols through flat sheet samples, pleated cartridge filters, and a 1000 cfm filter having 64 cartridges housed in a 2 x 2 x 1 ft. frame. The steel fiber media used in our study consists of 2 micron diameter stainless steel (316 L) fibers sintered together into sheets.

  14. Interaction between stainless steel and plutonium metal

    SciTech Connect

    Dunwoody, John T; Mason, Richard E; Freibert, Franz J; Willson, Stephen P; Veirs, Douglas K; Worl, Laura A; Archuleta, Alonso; Conger, Donald J

    2010-01-01

    Long-term storage of excess plutonium is of great concern in the U.S. as well as abroad. The current accepted configuration involves intimate contact between the stored material and an iron-bearing container such as stainless steel. While many safety scenario studies have been conducted and used in the acceptance of stainless steel containers, little information is available on the physical interaction at elevated temperatures between certain forms of stored material and the container itself. The bulk of the safety studies has focused on the ability of a package to keep the primary stainless steel containment below the plutonium-iron eutectic temperature of approximately 410 C. However, the interactions of plutonium metal with stainless steel have been of continuing interest. This paper reports on a scoping study investigating the interaction between stainless steel and plutonium metal in a pseudo diffusion couple at temperatures above the eutectic melt-point.

  15. Materials for Advanced Ultrasupercritical Steam Turbines Task 3: Materials for Non-Welded Rotors, Buckets, and BoltingMaterials for Advanced Ultrasupercritical Steam Turbines

    SciTech Connect

    Saha, Deepak

    2015-09-15

    The primary objective of the task was to characterize the materials suitable for mechanically coupled rotor, buckets and bolting operating with an inlet temperature of 760°C (1400°F). A previous study DOE-FC26-05NT42442, identified alloys such as Haynes®282®, Nimonic 105, Inconel 740, Waspaloy, Nimonic 263, and Inconel 617 as potential alloys that met the requirements for the necessary operating conditions. Of all the identified materials, Waspaloy has been widely utilized in the aviation industry in the form of disk and other smaller forgings, and sufficient material properties and vendor experience exist, for the design and manufacture of large components. The European program characterizing materials for A-USC conditions are evaluating Nimonic 263 and Inconel 617 for large components. Inconel 740 has been studied extensively as a part of the boiler consortium and is code approved. Therefore, the consortium focused efforts in the development of material properties for Haynes®282® and Nimonic 105 to avoid replicative efforts and provide material choices/trade off during the detailed design of large components. Commercially available Nimonic 105 and Haynes®282® were evaluated for microstructural stability by long term thermal exposure studies. Material properties requisite for design such as tensile, creep / rupture, low cycle fatigue, high cycle fatigue, fatigue crack growth rate, hold-time fatigue, fracture toughness, and stress relaxation are documented in this report. A key requisite for the success of the program was a need demonstrate the successful scale up of the down-selected alloys, to large components. All property evaluations in the past were performed on commercially available bar/billet forms. Components in power plant equipment such as rotors and castings are several orders in magnitude larger and there is a real need to resolve the scalability issue. Nimonic 105 contains high volume fraction y’ [>50%], and hence the alloy is best suited

  16. Nicotiana attenuata NaHD20 plays a role in leaf ABA accumulation during water stress, benzylacetone emission from flowers, and the timing of bolting and flower transitions

    PubMed Central

    Ré, Delfina A.; Dezar, Carlos A.; Chan, Raquel L.; Baldwin, Ian T.; Bonaventure, Gustavo

    2011-01-01

    Homeodomain-leucine zipper type I (HD-Zip I) proteins are plant-specific transcription factors associated with the regulation of growth and development in response to changes in the environment. Nicotiana attenuata NaHD20 was identified as an HD-Zip I-coding gene whose expression was induced by multiple stress-associated stimuli including drought and wounding. To study the role of NaHD20 in the integration of stress responses with changes in growth and development, its expression was silenced by virus-induced gene silencing (VIGS), and control and silenced plants were metabolically and developmentally characterized. Phytohormone profiling showed that NaHD20 plays a positive role in abscisic acid (ABA) accumulation in leaves during water stress and in the expression of some dehydration-responsive genes including ABA biosynthetic genes. Moreover, consistent with the high levels of NaHD20 expression in corollas, the emission of benzylacetone from flowers was reduced in NaHD20-silenced plants. Additionally, bolting time and the opening of the inflorescence buds was decelerated in these plants in a specific developmental stage without affecting the total number of flowers produced. Water stress potentiated these effects; however, after plants recovered from this condition, the opening of the inflorescence buds was accelerated in NaHD20-silenced plants. In summary, NaHD20 plays multiple roles in N. attenuata and among these are the coordination of responses to dehydration and its integration with changes in flower transitions. PMID:20713465

  17. Sugar beet contains a large CONSTANS-LIKE gene family including a CO homologue that is independent of the early-bolting (B) gene locus

    PubMed Central

    Chia, T. Y. P.; Müller, A.; Jung, C.; Mutasa-Göttgens, E. S.

    2008-01-01

    Floral transition in the obligate long-day (LD) plant sugar beet (Beta vulgaris ssp. vulgaris) is tightly linked to the B gene, a dominant early-bolting quantitative trait locus, the expression of which is positively regulated by LD photoperiod. Thus, photoperiod regulators like CONSTANS (CO) and CONSTANS-LIKE (COL) genes identified in many LD and short-day (SD)-responsive plants have long been considered constituents and/or candidates for the B gene. Until now, the photoperiod response pathway of sugar beet (a Caryophyllid), diverged from the Rosids and Asterids has not been identified. Here, evidence supporting the existence of a COL gene family is provided and the presence of Group I, II, and III COL genes in sugar beet, as characterized by different zinc-finger (B-box) and CCT (CO, CO-like, TOC) domains is demonstrated. BvCOL1 is identified as a close-homologue of Group 1a (AtCO, AtCOL1, AtCOL2) COL genes, hence a good candidate for flowering time control and it is shown that it maps to chromosome II but distant from the B gene locus. The late-flowering phenotype of A. thaliana co-2 mutants was rescued by over-expression of BvCOL1 thereby suggesting functional equivalence with AtCO, and it is shown that BvCOL1 interacts appropriately with the endogenous downstream genes, AtFT and AtSOC1 in the transgenic plants. Curiously, BvCOL1 has a dawn-phased diurnal pattern of transcription, mimicking that of AtCOL1 and AtCOL2 while contrasting with AtCO. Taken together, these data suggest that BvCOL1 plays an important role in the photoperiod response of sugar beet. PMID:18495636

  18. Recycling steel from grinding swarf

    SciTech Connect

    Fu, H.; Matthews, M.A.; Warner, L.S.

    1998-12-31

    Two cleaning processes have been investigated for removing contaminants (cutting oil with phosphorus ester) from high speed steel (HSS) griding swarf. One process uses an aqueous surfactant washing technique, and the second process uses supercritical carbon dioxide (SCCO{sub 2}) extraction. Both technical and preliminary financial analysis are performed to have a better evaluation of these two competing cleaning technologies. Bench scale aqueous washings have shown that the required phosphorus removal is easily obtained, but a sufficient oil removal is more difficult. The experimental results also indicate a strong dependence of the aqueous washing efficiency on the choice of a suitable surfactant. SCCO{sub 2} extraction at 80 C and 340 atm shows that approximately 80% of the oil can be removed from swarf during a 60-minute process to produce a batch of recyclable steel, and that the phosphorus removal also reaches the required level. The cost of processing swarf using either aqueous surfactant washing or SCCO{sub 2} extraction in a 3,000,000 lbs per year plant is analyzed and the market forces impacting the feasibility of recycling on a commercial basis are reviewed. Commercial scale recycling is, in part, dependent upon resolution of regulatory uncertainty on the definition of swarf. States regulating swarf as hazardous provide a significant financial incentive to recycle. In states that regulate swarf as a solid waste, low disposal costs provide a disincentive that must be balanced with the possible hidden, future liabilities of landfill disposal.

  19. Automated Steel Cleanliness Analysis Tool (ASCAT)

    SciTech Connect

    Gary Casuccio; Michael Potter; Fred Schwerer; Dr. Richard J. Fruehan; Dr. Scott Story

    2005-12-30

    The objective of this study was to develop the Automated Steel Cleanliness Analysis Tool (ASCATTM) to permit steelmakers to evaluate the quality of the steel through the analysis of individual inclusions. By characterizing individual inclusions, determinations can be made as to the cleanliness of the steel. Understanding the complicating effects of inclusions in the steelmaking process and on the resulting properties of steel allows the steel producer to increase throughput, better control the process, reduce remelts, and improve the quality of the product. The ASCAT (Figure 1) is a steel-smart inclusion analysis tool developed around a customized next-generation computer controlled scanning electron microscopy (NG-CCSEM) hardware platform that permits acquisition of inclusion size and composition data at a rate never before possible in SEM-based instruments. With built-in customized ''intelligent'' software, the inclusion data is automatically sorted into clusters representing different inclusion types to define the characteristics of a particular heat (Figure 2). The ASCAT represents an innovative new tool for the collection of statistically meaningful data on inclusions, and provides a means of understanding the complicated effects of inclusions in the steel making process and on the resulting properties of steel. Research conducted by RJLG with AISI (American Iron and Steel Institute) and SMA (Steel Manufactures of America) members indicates that the ASCAT has application in high-grade bar, sheet, plate, tin products, pipes, SBQ, tire cord, welding rod, and specialty steels and alloys where control of inclusions, whether natural or engineered, are crucial to their specification for a given end-use. Example applications include castability of calcium treated steel; interstitial free (IF) degasser grade slag conditioning practice; tundish clogging and erosion minimization; degasser circulation and optimization; quality assessment/steel cleanliness; slab, billet

  20. 77 FR 26993 - Airworthiness Directives; The Boeing Company Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-08

    ... 12866, (2) Is not a ``significant rule'' under the DOT Regulatory Policies and Procedures (44 FR 11034... require replacing titanium seat track bolts with corrosion resistant steel (CRES) bolts, repetitive... procedures for replacing titanium seat track bolts with CRES bolts, repetitive inspections for cracking...

  1. 77 FR 67593 - Steel Import Monitoring and Analysis System

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-13

    ... system can be accessed at http://ia.ita.doc.gov/steel/license/SIMA-FR-Notices.html . FOR FURTHER... 7529, which placed temporary tariffs on many steel imports and provided the steel industry time to... ``Steel Import Licensing and Surge Monitoring Program'' (67 FR 79845). In Proclamation 7741 of December...

  2. 29 CFR 1926.757 - Open web steel joists.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 29 Labor 8 2013-07-01 2013-07-01 false Open web steel joists. 1926.757 Section 1926.757 Labor... (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Steel Erection § 1926.757 Open web steel joists... and columns are not framed in at least two directions with solid web structural steel members, a...

  3. 29 CFR 1926.757 - Open web steel joists.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 29 Labor 8 2012-07-01 2012-07-01 false Open web steel joists. 1926.757 Section 1926.757 Labor... (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Steel Erection § 1926.757 Open web steel joists... and columns are not framed in at least two directions with solid web structural steel members, a...

  4. 29 CFR 1926.757 - Open web steel joists.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 8 2010-07-01 2010-07-01 false Open web steel joists. 1926.757 Section 1926.757 Labor... (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Steel Erection § 1926.757 Open web steel joists. (a) General. (1) Except as provided in paragraph (a)(2) of this section, where steel joists are...

  5. 49 CFR 192.315 - Wrinkle bends in steel pipe.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 3 2014-10-01 2014-10-01 false Wrinkle bends in steel pipe. 192.315 Section 192... Transmission Lines and Mains § 192.315 Wrinkle bends in steel pipe. (a) A wrinkle bend may not be made on steel... wrinkle bend on steel pipe must comply with the following: (1) The bend must not have any sharp kinks....

  6. 49 CFR 192.315 - Wrinkle bends in steel pipe.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 3 2011-10-01 2011-10-01 false Wrinkle bends in steel pipe. 192.315 Section 192... Transmission Lines and Mains § 192.315 Wrinkle bends in steel pipe. (a) A wrinkle bend may not be made on steel... wrinkle bend on steel pipe must comply with the following: (1) The bend must not have any sharp kinks....

  7. 49 CFR 178.504 - Standards for steel drums.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 3 2014-10-01 2014-10-01 false Standards for steel drums. 178.504 Section 178.504...-Oriented Packaging Standards § 178.504 Standards for steel drums. (a) The following are identification codes for steel drums: (1) 1A1 for a non-removable head steel drum; and (2) 1A2 for a removable...

  8. 49 CFR 192.105 - Design formula for steel pipe.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 3 2012-10-01 2012-10-01 false Design formula for steel pipe. 192.105 Section 192... for steel pipe. (a) The design pressure for steel pipe is determined in accordance with the following... § 192.113. T=Temperature derating factor determined in accordance with § 192.115. (b) If steel pipe...

  9. 49 CFR 192.105 - Design formula for steel pipe.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 3 2014-10-01 2014-10-01 false Design formula for steel pipe. 192.105 Section 192... for steel pipe. (a) The design pressure for steel pipe is determined in accordance with the following... § 192.113. T=Temperature derating factor determined in accordance with § 192.115. (b) If steel pipe...

  10. 49 CFR 178.504 - Standards for steel drums.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 3 2011-10-01 2011-10-01 false Standards for steel drums. 178.504 Section 178.504...-Oriented Packaging Standards § 178.504 Standards for steel drums. (a) The following are identification codes for steel drums: (1) 1A1 for a non-removable head steel drum; and (2) 1A2 for a removable...

  11. 49 CFR 192.315 - Wrinkle bends in steel pipe.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Wrinkle bends in steel pipe. 192.315 Section 192... Transmission Lines and Mains § 192.315 Wrinkle bends in steel pipe. (a) A wrinkle bend may not be made on steel... wrinkle bend on steel pipe must comply with the following: (1) The bend must not have any sharp kinks....

  12. 46 CFR 154.172 - Contiguous steel hull structure.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 5 2011-10-01 2011-10-01 false Contiguous steel hull structure. 154.172 Section 154.172... Structure § 154.172 Contiguous steel hull structure. (a) Except as allowed in paragraphs (b) and (c) of this... construction of the contiguous steel hull structure must meet the thickness and steel grade in Table 1 for...

  13. 49 CFR 192.105 - Design formula for steel pipe.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 3 2011-10-01 2011-10-01 false Design formula for steel pipe. 192.105 Section 192... for steel pipe. (a) The design pressure for steel pipe is determined in accordance with the following... § 192.113. T=Temperature derating factor determined in accordance with § 192.115. (b) If steel pipe...

  14. 49 CFR 192.105 - Design formula for steel pipe.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Design formula for steel pipe. 192.105 Section 192... for steel pipe. (a) The design pressure for steel pipe is determined in accordance with the following... § 192.113. T=Temperature derating factor determined in accordance with § 192.115. (b) If steel pipe...

  15. 29 CFR 1926.757 - Open web steel joists.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 8 2011-07-01 2011-07-01 false Open web steel joists. 1926.757 Section 1926.757 Labor... (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Steel Erection § 1926.757 Open web steel joists. (a) General. (1) Except as provided in paragraph (a)(2) of this section, where steel joists are...

  16. 49 CFR 178.504 - Standards for steel drums.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 3 2012-10-01 2012-10-01 false Standards for steel drums. 178.504 Section 178.504...-Oriented Packaging Standards § 178.504 Standards for steel drums. (a) The following are identification codes for steel drums: (1) 1A1 for a non-removable head steel drum; and (2) 1A2 for a removable...

  17. 49 CFR 192.105 - Design formula for steel pipe.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 3 2013-10-01 2013-10-01 false Design formula for steel pipe. 192.105 Section 192... for steel pipe. (a) The design pressure for steel pipe is determined in accordance with the following... § 192.113. T=Temperature derating factor determined in accordance with § 192.115. (b) If steel pipe...

  18. 46 CFR 154.172 - Contiguous steel hull structure.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 5 2014-10-01 2014-10-01 false Contiguous steel hull structure. 154.172 Section 154.172... Structure § 154.172 Contiguous steel hull structure. (a) Except as allowed in paragraphs (b) and (c) of this... construction of the contiguous steel hull structure must meet the thickness and steel grade in Table 1 for...

  19. 49 CFR 192.315 - Wrinkle bends in steel pipe.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 3 2013-10-01 2013-10-01 false Wrinkle bends in steel pipe. 192.315 Section 192... Transmission Lines and Mains § 192.315 Wrinkle bends in steel pipe. (a) A wrinkle bend may not be made on steel... wrinkle bend on steel pipe must comply with the following: (1) The bend must not have any sharp kinks....

  20. 46 CFR 154.172 - Contiguous steel hull structure.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 5 2012-10-01 2012-10-01 false Contiguous steel hull structure. 154.172 Section 154.172... Structure § 154.172 Contiguous steel hull structure. (a) Except as allowed in paragraphs (b) and (c) of this... construction of the contiguous steel hull structure must meet the thickness and steel grade in Table 1 for...

  1. 46 CFR 154.172 - Contiguous steel hull structure.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 5 2013-10-01 2013-10-01 false Contiguous steel hull structure. 154.172 Section 154.172... Structure § 154.172 Contiguous steel hull structure. (a) Except as allowed in paragraphs (b) and (c) of this... construction of the contiguous steel hull structure must meet the thickness and steel grade in Table 1 for...

  2. 29 CFR 1926.757 - Open web steel joists.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 8 2014-07-01 2014-07-01 false Open web steel joists. 1926.757 Section 1926.757 Labor... (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Steel Erection § 1926.757 Open web steel joists. (a) General. (1) Except as provided in paragraph (a)(2) of this section, where steel joists are...

  3. 46 CFR 154.172 - Contiguous steel hull structure.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Contiguous steel hull structure. 154.172 Section 154.172... Structure § 154.172 Contiguous steel hull structure. (a) Except as allowed in paragraphs (b) and (c) of this... construction of the contiguous steel hull structure must meet the thickness and steel grade in Table 1 for...

  4. 49 CFR 192.315 - Wrinkle bends in steel pipe.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 3 2012-10-01 2012-10-01 false Wrinkle bends in steel pipe. 192.315 Section 192... Transmission Lines and Mains § 192.315 Wrinkle bends in steel pipe. (a) A wrinkle bend may not be made on steel... wrinkle bend on steel pipe must comply with the following: (1) The bend must not have any sharp kinks....

  5. Recycling galvanized steel: Operating experience and benefits

    SciTech Connect

    Dudek, F.J.; Daniels, E.J.; Morgan, W.A.

    1993-08-01

    In response to the increase in consumption of galvanized steel for automobiles in the last decade and the problems associated with remelting larger quantities of galvanized steel scrap, a process is being developed to separate and recover the steel and zinc from galvanized ferrous scrap. The zinc is dissolved from the scrap in hot caustic using anodic assistance and is recovered electrolytically as dendritic powder. The dezinced ferrous scrap is rinsed and used directly. The process is effective for zinc, lead, and aluminum removal on loose and baled scrap and on all types of galvanized steel. The process has been pilot tested for batch treatment of 900 tonnes of mostly baled scrap. A pilot plant to continuously treat loose scrap, with a design capacity of 48,000 tonnes annually, has been in operation in East Chicago, Indiana since early in 1993. The first 450 t of scrap degalvanized in the pilot plant have residual zinc below 0.01% and sodium dragout below 0.01%. Use of degalvanized steel scrap decreases raw materials, environmental compliance, and opportunity costs to steel- and iron-makers. Availability of clean degalvanized scrap may enable integrated steel producers to recycle furnace dusts to the sinter plant and EAF shops to produce flat products without use of high quality scrap alternatives such as DRI, pig iron, or iron carbide. Recycling the components of galvanized steel scrap saves primary energy, decreases zinc imports, and adds value to the scrap. The quantities of zinc available by the year 2000 from prompt and obsolete automotive scrap win approach 25% of zinc consumed in the major automotive production centers of the world. Zinc recycling from galvanized steel scrap, either before or after scrap melting, will have to be implemented.

  6. Steel Creek wildlife: L-Lake/Steel Creek Biological Monitoring Program, January 1986--December 1987

    SciTech Connect

    Giffin, M.A.; Patterson, K.K.

    1988-03-01

    Reptile and amphibian populations in Steel Creek below L-Lake were assessed in monthly or quarterly sampling programs. Thirty-eight species of reptiles or amphibians were collected during 1987 in the Steel Creek corridor below the L-Lake impoundment, and in the delta and channel. Juvenile turtles and alligators, and larval amphibians were observed or collected during the study, indicating continued reproduction in Steel Creek. The reptile and amphibian populations in Steel Creek show no indication of any effect due to the impoundment of the lake or the operation of L-Reactor. Waterfowl and associated birds in Steel Creek below L-Lake were observed, in conjunction with other sampling programs, during winter--spring and fall--winter migrations. Nine species of waterfowl and five species of associated birds were observed in 1987 in the Steel Creek corridor below the L-Lake impoundment and in the delta and channel.

  7. Direct Alloying of Steel with Nickel Concentrate

    NASA Astrophysics Data System (ADS)

    Nokhrina, O. I.; Rozhikhina, I. D.; Proshunin, I. E.

    2016-08-01

    A technology of alloying steel with nickel reduced from nickel concentrate is analysed and developed. Limits of reduction concentration areas are defined. An optimal composition of nickel concentrate pellets and a method of feeding them into the furnace are deduced from experiments. It is proved that when pellets made of nickel concentrate and coke are added into the charge during steel smelting by the technology of alloyed scrap remelting, nickel recovery achieves 92-95%. The technology was tested by smelting DSP-40 steel.

  8. Tritiated Water Interaction with Stainless Steel

    SciTech Connect

    Glen R. Longhurst

    2007-05-01

    Experiments conducted to study tritium permeation of stainless steel at ambient and elevated temperatures revealed that HT converts relatively quickly to HTO. Further, the HTO partial pressure contributes essentially equally with elemental tritium gas in driving permeation through the stainless steel. Such permeation appears to be due to dissociation of the water molecule on the hot stainless steel surface. There is an equilibrium concentration of HTO vapor above adsorbed gas on the walls of the experimental apparatus evident from freezing transients. The uptake process of tritium from the carrier gas involves both surface adsorption and isotopic exchange with surface bound water.

  9. Steel Foil Improves Performance Of Blasting Caps

    NASA Technical Reports Server (NTRS)

    Bement, Laurence J.; Perry, Ronnie; Schimmel, Morry L.

    1990-01-01

    Blasting caps, which commonly include deep-drawn aluminum cups, give significantly higher initiation performance by application of steel foils on output faces. Steel closures 0.005 in. (0.13 mm) thick more effective than aluminum. Caps with directly bonded steel foil produce fragment velocities of 9,300 ft/s (2.8 km/s) with large craters and unpredictable patterns to such degree that no attempts made to initiate explosions. Useful in military and aerospace applications and in specialized industries as mining and exploration for oil.

  10. Ultrasonic attenuation in pearlitic steel.

    PubMed

    Du, Hualong; Turner, Joseph A

    2014-03-01

    Expressions for the attenuation coefficients of longitudinal and transverse ultrasonic waves are developed for steel with pearlitic microstructure. This type of lamellar duplex microstructure influences attenuation because of the lamellar spacing. In addition, longitudinal attenuation measurements were conducted using an unfocused transducer with 10 MHz central frequency on the cross section of a quenched railroad wheel sample. The dependence of longitudinal attenuation on the pearlite microstructure is observed from the changes of longitudinal attenuation from the quenched tread surface to deeper locations. The results show that the attenuation value is lowest and relatively constant within the quench depth, then increases linearly. The experimental results demonstrate a reasonable agreement with results from the theoretical model. Ultrasonic attenuation provides an important non-destructive method to evaluate duplex microstructure within grains which can be implemented for quality control in conjunction with other manufacturing processes.

  11. Steel pressure vessels for hydrostatic pressures to 50 kilobars.

    PubMed

    Lavergne, A; Whalley, E

    1978-07-01

    Cylindrical steel pressure vessels are described that can be used for hydrostatic pressures up to 50 kilobars. Monoblock vessels of 350 maraging steel can be used to 40 kilobars and compound vessels with an inner vessel of 350 maraging steel and an outer vessel of 300 maraging steel to 50 kilobars. Neither requires the cylinder to be end loaded, and so they are much easier to use than the more usual compound vessels with a tungsten carbide inner and steel outer vessel.

  12. Project B: Improved Liquid Steel Feed For Slab Casters

    SciTech Connect

    Brent S. Isaacson; Mike Slepian; Thomas Richter

    1998-10-01

    This report describes the completion of the development of an electromagnetic valve to control liquid steel flow for improved liquid steel feeding for slab casters. Achievements result from a joint research effort between Westinghouse Science and Technology Center, North American Refractories and U.S. Steel. This effort is part of the American Iron and Steel Institute's (AISI) Advanced Process Control Program, a collaboration between the U.S. Department of Energy (DOE) and fifteen North American steel makers.

  13. Microstructural characterization in dissimilar friction stir welding between 304 stainless steel and st37 steel

    SciTech Connect

    Jafarzadegan, M.; Feng, A.H.; Abdollah-zadeh, A.; Saeid, T.; Shen, J.; Assadi, H.

    2012-12-15

    In the present study, 3 mm-thick plates of 304 stainless steel and st37 steel were welded together by friction stir welding at a welding speed of 50 mm/min and tool rotational speed of 400 and 800 rpm. X-ray diffraction test was carried out to study the phases which might be formed in the welds. Metallographic examinations, and tensile and microhardness tests were used to analyze the microstructure and mechanical properties of the joint. Four different zones were found in the weld area except the base metals. In the stir zone of the 304 stainless steel, a refined grain structure with some features of dynamic recrystallization was evidenced. A thermomechanically-affected zone was characterized on the 304 steel side with features of dynamic recovery. In the other side of the stir zone, the hot deformation of the st37 steel in the austenite region produced small austenite grains and these grains transformed to fine ferrite and pearlite and some products of displacive transformations such as Widmanstatten ferrite and martensite by cooling the material after friction stir welding. The heat-affected zone in the st37 steel side showed partially and fully refined microstructures like fusion welding processes. The recrystallization in the 304 steel and the transformations in the st37 steel enhanced the hardness of the weld area and therefore, improved the tensile properties of the joint. - Highlights: Black-Right-Pointing-Pointer FSW produced sound welds between st37 low carbon steel and 304 stainless steel. Black-Right-Pointing-Pointer The SZ of the st37 steel contained some products of allotropic transformation. Black-Right-Pointing-Pointer The material in the SZ of the 304 steel showed features of dynamic recrystallization. Black-Right-Pointing-Pointer The finer microstructure in the SZ increased the hardness and tensile strength.

  14. Stainless steel to titanium bimetallic transitions

    NASA Astrophysics Data System (ADS)

    Kaluzny, J. A.; Grimm, C.; Passarelli, D.

    2015-12-01

    In order to use stainless steel piping in an LCLS-II (Linac Coherent Light Source Upgrade) cryomodule, stainless steel to titanium bimetallic transitions are needed to connect the stainless steel piping to the titanium cavity helium vessel. Explosion bonded stainless steel to titanium transition pieces and bimetallic transition material samples have been tested. A sample transition tube was subjected to tests and x-ray examinations between tests. Samples of the bonded joint material were impact and tensile tested at room temperature as well as liquid helium temperature. The joint has been used successfully in horizontal tests of LCLS-II cavity helium vessels and is planned to be used in LCLS-II cryomodules. Results of material sample and transition tube tests will be presented. Operated by Fermi Research Alliance, LLC under Contract No. De-AC02-07CH11359 with the United States Department of Energy.

  15. Clean Cast Steel Technology, Phase IV

    SciTech Connect

    Charles E. Bates

    2003-02-24

    The objective of the Clean Cast Steel Technology Program was to improve casting product quality by removing or minimizing oxide defects and to allow the production of higher integrity castings for high speed machining lines. Previous research has concentrated on macro-inclusions that break, chip, or crack machine tool cutters and drills and cause immediate shutdown of the machining lines. The overall goal of the project is to reduce the amount of surface macro-inclusions and improve the machinability of steel castings. Macro-inclusions and improve the machinability of steel castings. Macro-inclusions have been identified by industrial sponsors as a major barrier to improving the quality and marketability of steel castings.

  16. Development of a carburizing stainless steel alloy

    SciTech Connect

    Wert, D.E. )

    1994-06-01

    A new carburizing stainless steel alloy that resists corrosion, heat, and fatigue has been developed for bearing and gear applications. Pyrowear 675 Stainless alloy is vacuum induction melted and vacuum arc remelted (VIM/VAR) for aircraft-quality cleanliness. Test results show that it has corrosion resistance similar to that of AISI Type 440-C stainless, and its rolling fatigue resistance is superior to that of AISI M50 (UNS K88165). In contrast to alloy gear steels and Type 440C, Pyrowear 675 maintains case hardness of HRC 60 at operating temperatures up to 200 C (400 F). Impact and fracture toughness are superior to that of other stainless bearing steels, which typically are relatively brittle and can break under severe service. Toughness is also comparable or superior to conventional noncorrosion-resistant carburizing bearing steels, such as SAE Types 8620 and 9310.

  17. Hydrogen compatibility handbook for stainless steels

    SciTech Connect

    Caskey, G.R. Jr.

    1983-06-01

    This handbook compiles data on the effects of hydrogen on the mechanical properties of stainless steels and discusses this data within the context of current understanding of hydrogen compatibility of metals. All of the tabulated data derives from continuing studies of hydrogen effects on materials that have been conducted at the Savannah River Laboratory over the past fifteen years. Supplementary data from other sources are included in the discussion. Austenitic, ferritic, martensitic, and precipitation hardenable stainless steels have been studied. Damage caused by helium generated from decay of tritium is a distinctive effect that occurs in addition to the hydrogen isotopes protium and deuterium. The handbook defines the scope of our current knowledge of hydrogen effects in stainless steels and serves as a guide to selection of stainless steels for service in hydrogen.

  18. Lightweight Steel Solutions for Automotive Industry

    SciTech Connect

    Lee, Hong Woo; Kim, Gyosung; Park, Sung Ho

    2010-06-15

    Recently, improvement in fuel efficiency and safety has become the biggest issue in worldwide automotive industry. Although the regulation of environment and safety has been tightened up more and more, the majority of vehicle bodies are still manufactured from stamped steel components. This means that the optimized steel solutions enable to demonstrate its ability to reduce body weight with high crashworthiness performance instead of expensive light weight materials such as Al, Mg and composites. To provide the innovative steel solutions for automotive industry, POSCO has developed AHSS and its application technologies, which is directly connected to EVI activities. EVI is a technical cooperation program with customer covering all stages of new car project from design to mass production. Integrated light weight solutions through new forming technologies such as TWB, hydroforming and HPF are continuously developed and provided for EVI activities. This paper will discuss the detailed status of these technologies especially light weight steel solutions based on innovative technologies.

  19. Adhesive bonding between polyamide and steel

    NASA Astrophysics Data System (ADS)

    Vettegren', V. I.; Bashkarev, A. Ya.; Savitskii, A. V.; Shcherbakov, I. P.; Sytov, V. V.; Mamalimov, R. I.

    2015-08-01

    Fluorescence and IR absorption spectra are taken of coatings obtained by applying polyamide 6 powder on a steel substrate heated above the polymer melting point and subsequently cooling to room temperature. It follows from the coating spectra that the energy of a π* → n transition in the C—O bonds of polyamide decreases. Simultaneously, the maximum of a band assigned to the deformation vibrations of N—H bonds shifts toward longer wavelengths. These effects are explained by the formation of coordination bonds between Fe2+ ions having diffused from the steel into the polymer and nitrogen atoms entering into polyamide 6 molecules. As a result, a coordination-compound-saturated diffusion layer up to 100 µm thick arises near the steel surface. Coordination compounds squeeze the framework of the polyamide 6 molecule roughly by 0.06%. Eventually, a polyamide layer that is stronger than the surroundings appears at the polyamide 6—steel interface.

  20. Precise carbon control of fabricated stainless steel

    DOEpatents

    Nilsen, R.J.

    1975-12-01

    A process is described for controlling the carbon content of fabricated stainless steel components including the steps of heat treating the component in hydrogen atmospheres of varying dewpoints and carbon potentials.