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Sample records for rivets

  1. Riveting in metal airplane construction. Part II : riveting methods and equipment (concluded)

    NASA Technical Reports Server (NTRS)

    Pleines, Wilhelm

    1930-01-01

    This report includes descriptive material on rivet inspection, types of rivets and sizes. Tabular data on shearing strength of rivets at failure, ultimate shear of various rivets, tensile tests of rivet plate, and tensile strength values of riveted joints.

  2. Riveting-force gage

    NASA Technical Reports Server (NTRS)

    Rotta, J. W., Jr.

    1979-01-01

    Gage monitors riveting forces applied when components are mounted on printed-circuit boards. Correct swaging pressures have been established for specific substrate materials such as phenolics and ceramics.

  3. Rivet user manual

    NASA Astrophysics Data System (ADS)

    Buckley, Andy; Butterworth, Jonathan; Grellscheid, David; Hoeth, Hendrik; Lönnblad, Leif; Monk, James; Schulz, Holger; Siegert, Frank

    2013-12-01

    This is the manual and user guide for the Rivet system for the validation and tuning of Monte Carlo event generators. As well as the core Rivet library, this manual describes the usage of the rivet program and the AGILe generator interface library. The depth and level of description is chosen for users of the system, starting with the basics of using validation code written by others, and then covering sufficient details to write new Rivet analyses and calculational components. Catalogue identifier: AEPS_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEPS_v1_0.html Program obtainable from: CPC Program Library, Queen’s University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 571126 No. of bytes in distributed program, including test data, etc.: 4717522 Distribution format: tar.gz Programming language: C++, Python. Computer: PC running Linux, Mac. Operating system: Linux, Mac OS. RAM: 20 MB Classification: 11.9, 11.2. External routines: HepMC (https://savannah.cern.ch/projects/hepmc/), GSL (http://www.gnu.org/software/gsl/manual/gsl-ref.html), FastJet (http://fastjet.fr/), Python (http://www.python.org/), Swig (http://www.swig.org/), Boost (http://www.boostsoftware.com/), YAML (http://www.yaml.org/spec/1.2/spec.html) Nature of problem: Experimental measurements from high-energy particle colliders should be defined and stored in a general framework such that it is simple to compare theory predictions to them. Rivet is such a framework, and contains at the same time a large collection of existing measurements. Solution method: Rivet is based on HepMC events, a standardised output format provided by many theory simulation tools. Events are processed by Rivet to generate histograms for the requested list of analyses, incorporating all experimental phase space cuts and histogram definitions. Restrictions: Cannot calculate

  4. Riveted joints in thin plates

    NASA Technical Reports Server (NTRS)

    Hilbes, W

    1930-01-01

    The method of riveting by forming the closing head under increasing pressure or by a series of hammer blows is investigated. The question as to the best edge distance, i.e. that distance from the rivet center to the plate edge below which it is unadvisable to go and, at the same time useless to go beyond, was examined. The slippage of plates which occurs under the effect of a certain stress, does not completely disappear on unloading. The elastic form change is essentially a function of the elasticity modulus, the slip modulus, the supporting moment, the rivet spacing, etc.

  5. Riveting in metal airplane construction. Part IV : strength of riveted joints in duralumin (concluded)

    NASA Technical Reports Server (NTRS)

    Pleines, Wilhelm

    1930-01-01

    Tests were made to determine the crushing strength of a riveted joint, in order to define the difference in crushing stregth between a strictly bolted joint and a riveted joint. The object was to tabulate the crushing strength by failure on various plate thicknesses for a one-rivet double-shear riveted joint.

  6. A Flush-Rivet Milling Tool

    NASA Technical Reports Server (NTRS)

    Gottlieb, Robert

    1942-01-01

    The investigation of machine-countersunk flush rivets for aircraft described in reference 1 revealed the necessity of having the height of the rivet heads greater than the depth of the countersunk holes if tightly riveted joints were to be obtained. If ordinary roundhead rivets were inserted from the opposite side of the joint and the countersunk heads formed in the driving of the rivets filled the countersunk holes completely, still tighter joints were obtained. In either case the rivets protruded above the skin surface after driving, and the protruding portion of the rivet heads had to be removed in order to obtain flush rivets. A number of requests have been received for a description of the tool used to mill off the protruding portion of the rivet heads. This report contains assembly and detail drawings of the latest flush-rivet milling tool used at the NACA Structures Research Laboratory. Figure 6 shows the tool in operation. This tool is quite satisfactory for 1/8-inch rivets, but a more powerful motor is recommended for use with larger rivets.

  7. Mechanical Properties of Aluminum-alloy Rivets

    NASA Technical Reports Server (NTRS)

    Brueggeman, Wm C

    1936-01-01

    The development of metal construction for aircraft has created a need for accurate and detailed information regarding the strength of riveted joints in aluminum-alloy structures. To obtain this information the National Bureau of Standards in cooperation with the National Advisory Committee for Aeronautics is investigating the strength of riveted joints in aluminum alloys. The strength of riveted joints may be influenced by the form of the head, the ratio of the rivet diameter to the sheet thickness, the driving stress, and other factors. This note gives the results of tests to develop the riveting technique for test specimens and to determine the effects of these factors.

  8. Performance Optimization of Self-Piercing Rivets through Analytical Rivet Strength Estimation

    SciTech Connect

    Sun, Xin; Khaleel, Mohammad A.

    2005-08-01

    This paper presents the authors' work on strength optimization and failure mode prediction of self-piercing rivets (SPR) for automotive applications. The limit load-based strength estimator is used to estimate the static strength of an SPR under cross tension loading configuration. Failure modes associated with the estimated failure strength are also predicted. Experimental strength and failure mode observations are used to validate the model. It is shown that the strength of an SPR joint depends on the material and gage combinations, rivet design, die design and riveting direction. The rivet strength estimator is then used to optimize the rivet strength by comparing the measured rivet strength and failure mode with the predicted ones. Two illustrative examples are used in which rivet strength is optimized by changing rivet design and riveting direction from the original manufacturing parameters.

  9. Oxidation-Strengthened High-Temperature Rivets

    NASA Technical Reports Server (NTRS)

    Mclemore, R. L.

    1982-01-01

    Shear strength of titanium-niobium rivets improves with oxidation. Ti-Nb rivets developed for fastening parts of Space Shuttle thrustors may be suitable also for other high-temperature applications in oxidizing environments--for example, in burner cans of commercial jet engines and boilers and retorts for coal gasification systems.

  10. Caring for Rosie the Riveter's Children

    ERIC Educational Resources Information Center

    MacKenzie, Bill

    2011-01-01

    During the Second World War, women in the United States who worked in the war industries in such jobs as welders, riveters, heavy machinery operators, and parachute riggers were heralded in the media as "Rosie the Riveter." From 1943 to 1945 a fortunate few of these workplace pioneers participated in a memorable experiment in child care at Kaiser…

  11. 49 CFR 230.28 - Higher shearing strength of rivets.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Appurtenances Strength of Materials § 230.28 Higher shearing strength of rivets. A higher shearing strength may be used for rivets when it can be shown through testing that the rivet material used is of such... 49 Transportation 4 2013-10-01 2013-10-01 false Higher shearing strength of rivets. 230.28...

  12. 49 CFR 230.28 - Higher shearing strength of rivets.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Appurtenances Strength of Materials § 230.28 Higher shearing strength of rivets. A higher shearing strength may be used for rivets when it can be shown through testing that the rivet material used is of such... 49 Transportation 4 2011-10-01 2011-10-01 false Higher shearing strength of rivets. 230.28...

  13. 49 CFR 230.28 - Higher shearing strength of rivets.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Appurtenances Strength of Materials § 230.28 Higher shearing strength of rivets. A higher shearing strength may be used for rivets when it can be shown through testing that the rivet material used is of such... 49 Transportation 4 2014-10-01 2014-10-01 false Higher shearing strength of rivets. 230.28...

  14. 49 CFR 230.28 - Higher shearing strength of rivets.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Appurtenances Strength of Materials § 230.28 Higher shearing strength of rivets. A higher shearing strength may be used for rivets when it can be shown through testing that the rivet material used is of such... 49 Transportation 4 2012-10-01 2012-10-01 false Higher shearing strength of rivets. 230.28...

  15. 49 CFR 230.28 - Higher shearing strength of rivets.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Appurtenances Strength of Materials § 230.28 Higher shearing strength of rivets. A higher shearing strength may be used for rivets when it can be shown through testing that the rivet material used is of such... 49 Transportation 4 2010-10-01 2010-10-01 false Higher shearing strength of rivets. 230.28...

  16. The role of rivet installation on the fatigue performance of riveted lap joints

    NASA Astrophysics Data System (ADS)

    Rans, Calvin D.

    Solid rivets are widely used as mechanical fasteners in airframe applications due to their relative low cost and good fatigue performance. Although rivet installation is known to influence this fatigue performance, variabilities in hand riveting practices make exploiting rivet installation as a design variable difficult. Developments in riveting technology have led to force-controlled rivet squeezers and fully automated riveting gantries, improving the consistency of rivet installation and providing the opportunity to exploit its influence on fatigue. This dissertation describes a research program undertaken to examine the influence of rivet installation on the fatigue performance of riveted lap joints and identify what aspects can be exploited during design. A combination of finite element analyses and experimental techniques were used to investigate the role of rivet installation on the formation of residual stresses and on secondary bending stresses in a loaded joint, two aspects established as critical to the fatigue performance of riveted lap joints. Crack growth reconstructions of fracture surfaces marked using a special marker fatigue spectrum were also completed in order to quantify the effects of these residual and secondary bending stresses on fatigue performance. Additionally, variations in the effects of rivet installation on traditional monolithic aluminum sheet materials and hybrid aluminum-fibre glass laminates known as GLARE were also investigated. Results from these investigations provided new insights into the role of rivet installation on fatigue. The radial expansion mechanism to which residual stress formation during riveting is typically attributed was observed to be a secondary mechanism relative to the through-thickness compression of the joined sheets. The location and magnitude of peak secondary bending stresses were found to be directly influenced by rivet head geometry. In certain cases, shifts in the location of peak secondary bending

  17. Riveting in metal airplane construction. Part III : strength of riveted joints in duralumin (continued)

    NASA Technical Reports Server (NTRS)

    Pleines, Wilhelm

    1930-01-01

    This report includes strength of riveted joints in duralumin, descriptions of test procedure and results of tests. Tabulated data includes: curshing strength by failure for various conditions, shearing strength of hole edge zone in direction of tearing, tearing strengths of plates weakened by rivet holes, and enlargement of holes at beginning of break.

  18. Multiple-site-damage fatigue of riveted joints

    NASA Astrophysics Data System (ADS)

    Schijve, J.

    1992-04-01

    Results of fatigue tests in riveted lap joints, including fractographic observations, are presented and analyzed. They indicate that the load transmission in a riveted lap joint is a rather complex phenomenon, as confirmed by quite different crack initiation mechanisms. It may not be expected that fracture mechanics predicts early crack growth with a practically useful degree of accuracy. Most important, the fractographic analysis reveals, that if there are visible cracks in a riveted lap joint, there are many small cracks at most rivet holes in the same critical row of rivets. A multiple site damage situation is present. The conclusion also applies to fuselage lap joints. Scatter in laboratory tests in riveted lap joint specimens is relatively low. However, scatter of riveted joints in a fleet of aircraft may be larger for several reasons. Crack growth in riveted lap joints may be sufficiently slow to allow a timely detection in service. For aging aircraft this should be confirmed by full scale testing.

  19. 46 CFR 59.10-15 - Rivets and staybolts.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... VESSELS AND APPURTENANCES Welding Repairs to Boilers and Pressure Vessels in -Service § 59.10-15 Rivets and staybolts. (a) It is not permitted to reinforce or build up by welding the heads of rivets or staybolts that have deteriorated. Such rivets or staybolts shall be replaced. The seal welding of...

  20. 46 CFR 59.10-15 - Rivets and staybolts.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... VESSELS AND APPURTENANCES Welding Repairs to Boilers and Pressure Vessels in -Service § 59.10-15 Rivets and staybolts. (a) It is not permitted to reinforce or build up by welding the heads of rivets or staybolts that have deteriorated. Such rivets or staybolts shall be replaced. The seal welding of...

  1. 46 CFR 59.10-15 - Rivets and staybolts.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... VESSELS AND APPURTENANCES Welding Repairs to Boilers and Pressure Vessels in -Service § 59.10-15 Rivets and staybolts. (a) It is not permitted to reinforce or build up by welding the heads of rivets or staybolts that have deteriorated. Such rivets or staybolts shall be replaced. The seal welding of...

  2. 46 CFR 59.10-15 - Rivets and staybolts.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... VESSELS AND APPURTENANCES Welding Repairs to Boilers and Pressure Vessels in -Service § 59.10-15 Rivets and staybolts. (a) It is not permitted to reinforce or build up by welding the heads of rivets or staybolts that have deteriorated. Such rivets or staybolts shall be replaced. The seal welding of...

  3. 46 CFR 59.10-15 - Rivets and staybolts.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... VESSELS AND APPURTENANCES Welding Repairs to Boilers and Pressure Vessels in -Service § 59.10-15 Rivets and staybolts. (a) It is not permitted to reinforce or build up by welding the heads of rivets or staybolts that have deteriorated. Such rivets or staybolts shall be replaced. The seal welding of...

  4. Mechanical Properties of Flush-Riveted Joints

    NASA Technical Reports Server (NTRS)

    Brueggeman, W C; Roop, Frederick C

    1940-01-01

    The strength of representative types of flush-riveted joints has been determined by testing 865 single-shearing, double-shearing, and tensile specimens representing 7 types of rivet and 18 types of joint. The results, presented in graphic form, show the stress at failure, type of failure, and d/t ratio. In general, dimpled joints were appreciably stronger than countersunk or protruding-head joints, but their strength was greatly influenced by constructional details. The optimum d/t ratios have been determined for the several kinds of joints. Photomicrographs of each type show constructional details and, in several instances, cracks in the sheet.

  5. Mechanical Properties of Flush-Riveted Joints

    NASA Technical Reports Server (NTRS)

    Bruggeman, Wm. C.; Roop, Frederick C.

    1940-01-01

    The strength of representative types of flush-riveted joints has been determined by testing 865 single-shearing, double-shearing, and tensile specimens representing 7 types of rivet and 18 types of joint. The results, presented in graphic form, show the stress at failure, type of failure, and d/t ratio. In general, 'dimpled' joints were appreciably stronger than countersunk or protruding-head joints, but their strength was greatly influenced by constructional details. The optimum d/t ratios have been determined for the several kinds of joints. Photomacrographs of each type show constructional details and, in several instances, cracks in the sheet.

  6. An investigation into the acute vascular effects of riveting.

    PubMed Central

    McKenna, K M; McGrann, S; Blann, A D; Allen, J A

    1993-01-01

    Measurements were made on 46 pairs of riveters and matched control subjects before and after a morning's work. Before starting work, the mean resting finger systolic pressure was 112 (SEM 3.3) mm Hg in the riveters, similar to 117 (1.7) in the control subjects. After cooling the middle phalanx to 10 degrees C for five minutes, 16 riveters but only one control subject exhibited digital vasospasm and these numbers were unaltered after a morning's work. A subgroup of riveters whose role was always to provide counter pressure to the rivet gun showed a higher incidence (45%) of cold induced vasospasm than did riveters who invariably held the gun (10%) or rotated between both roles (27%). Plasma levels of three markers of vascular activity, endothelin-1 (ET-1), von Willebrand factor antigen (vWFAg), and angiotensin converting enzyme (ACE), were measured in non-smoking riveters and control subjects. Before work, ET-1 concentrations were slightly lower (p < 0.05) in the riveters, but vWFAg concentration and ACE activity were similar in riveters and control subjects. Riveting for a morning did not alter ET-1 concentration or ACE activity but did induce a small increase (p < 0.05) in vWFAg concentration, which may indicate damage to the endothelium. This type of vascular assessment may be helpful in assessing vasospastic complications in workers exposed to vibration. PMID:8435349

  7. The Effect of Surface Irregularities on Wing Drag. I. Rivets and Spot Welds. 1; Rivets and Spot Welds

    NASA Technical Reports Server (NTRS)

    Hood, Manley J.

    1938-01-01

    Tests have been conducted in the NACA 8-foot high-speed wind tunnel to determine the effect of exposed rivet heads and spot welds on wing drag. Most of the tests were made with an airfoil of 5-foot chord. The air speed was varied from 80 to 500 miles per hour and the lift coefficient from 0 to 0.30. The increases in the drag of the 5-foot airfoil varied from 6%, due to countersunk rivets, to 27%, due to 3/32-inch brazier-head rivets, with the rivets in a representative arrangement. The drag increases caused by protruding rivet heads were roughly proportional to the height of the heads. With the front row of rivets well forward, changes in spanwise pitch had negligible effects on drag unless the pitch was more than 2.5% of the chord. Data are presented for evaluating the drag reduction attained by removing rivets from the forward part of the wing surface; for example, it is shown that over 70% of the rivet drag is caused by the rivets on the forward 30% of the airfoil in a typical case.

  8. Revolving Eddy-Current Probe Detects Cracks Near Rivets

    NASA Technical Reports Server (NTRS)

    Namkung, Min; Wincheski, Buzz; Fulton, James P.; Nath, Shridhar; Simpson, John

    1995-01-01

    Scanning eddy-current probe in circular pattern increases sensitivity with which probe indicates fatigue cracks and other defects in metal surfaces in vicinity of rivets. Technique devised to facilitate inspection of riveted joints in aircraft. Eddy-current probe in question described in "Electro-magnetic Flaw Detector Is Easier To Use" (LAR-15046).

  9. 49 CFR 230.27 - Maximum shearing strength of rivets.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Appurtenances Strength of Materials § 230.27 Maximum shearing strength of rivets. The maximum shearing strength... 49 Transportation 4 2011-10-01 2011-10-01 false Maximum shearing strength of rivets. 230.27 Section 230.27 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL...

  10. 49 CFR 230.27 - Maximum shearing strength of rivets.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Appurtenances Strength of Materials § 230.27 Maximum shearing strength of rivets. The maximum shearing strength... 49 Transportation 4 2014-10-01 2014-10-01 false Maximum shearing strength of rivets. 230.27 Section 230.27 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL...

  11. 49 CFR 230.27 - Maximum shearing strength of rivets.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Appurtenances Strength of Materials § 230.27 Maximum shearing strength of rivets. The maximum shearing strength... 49 Transportation 4 2010-10-01 2010-10-01 false Maximum shearing strength of rivets. 230.27 Section 230.27 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL...

  12. 49 CFR 230.27 - Maximum shearing strength of rivets.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Appurtenances Strength of Materials § 230.27 Maximum shearing strength of rivets. The maximum shearing strength... 49 Transportation 4 2013-10-01 2013-10-01 false Maximum shearing strength of rivets. 230.27 Section 230.27 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL...

  13. 49 CFR 230.27 - Maximum shearing strength of rivets.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Appurtenances Strength of Materials § 230.27 Maximum shearing strength of rivets. The maximum shearing strength... 49 Transportation 4 2012-10-01 2012-10-01 false Maximum shearing strength of rivets. 230.27 Section 230.27 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL...

  14. 46 CFR 109.573 - Riveting, welding, and burning operations.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Riveting, welding, and burning operations. 109.573... DRILLING UNITS OPERATIONS Miscellaneous § 109.573 Riveting, welding, and burning operations. Except as..., welding, or burning— (1) In a fuel tank; (2) On the boundary of a fuel tank; (3) On pipelines,...

  15. Residual Strength Analyses of Riveted Lap-Splice Joints

    NASA Technical Reports Server (NTRS)

    Seshadri, B. R.; Newman, J. C., Jr.

    2000-01-01

    The objective of this paper was to analyze the crack-linkup behavior in riveted-stiffened lap-splice joint panels with small multiple-site damage (MSD) cracks at several adjacent rivet holes. Analyses are based on the STAGS (STructural Analysis of General Shells) code with the critical crack-tip-opening angle (CTOA) fracture criterion. To account for high constraint around a crack front, the "plane strain core" option in STAGS was used. The importance of modeling rivet flexibility with fastener elements that accurately model load transfer across the joint is discussed. Fastener holes are not modeled but rivet connectivity is accounted for by attaching rivets to the sheet on one side of the cracks that simulated both the rivet diameter and MSD cracks. Residual strength analyses made on 2024-T3 alloy (1.6-mm thick) riveted-lap-splice joints with a lead crack and various size MSD cracks were compared with test data from Boeing Airplane Company. Analyses were conducted for both restrained and unrestrained buckling conditions. Comparison of results from these analyses and results from lap-splice-joint test panels, which were partially restrained against buckling indicate that the test results were bounded by the failure loads predicted by the analyses with restrained and unrestrained conditions.

  16. Strength Estimation of Self-Piercing Rivets using Lower Bound Limit Load Analysis

    SciTech Connect

    Sun, Xin; Khaleel, Mohammad A.

    2005-08-01

    This paper summarizes the authors' work on strength and failure mode estimation of self-piercing rivets (SPR) for automotive applications. First, the static cross tension strength of an SPR joint is estimated using a lower bound limit load based strength estimator. Failure mode associated with the predicted failure strength can also be identified. It is shown that the cross tension strength of an SPR joint depends on the material and gage combinations, rivet design, die design and riveting direction. The analytical rivet strength estimator is then validated by experimental rivet strength measurements and failure mode observations from nine SPR joint populations with various material and gage combinations. Next, the estimator is used to optimize rivet strength. Two illustrative examples are presented in which rivet strength is improved by changing rivet length and riveting direction from the original manufacturing parameters.

  17. 12. Detail view (looking east) of riveted cconnection of top ...

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

    12. Detail view (looking east) of riveted cconnection of top chord and vertical members at the second panel point north from south abutment of Moody Bridge. - Moody Bridge, Spanning South Fork Eel River, Garberville, Humboldt County, CA

  18. 23. NORTHEAST TO CIRCA 1875 POWER SHEAR, PUNCH, AND RIVETING ...

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

    23. NORTHEAST TO CIRCA 1875 POWER SHEAR, PUNCH, AND RIVETING MACHINE SET UP TO DEMONSTRATE USE IN RIVETING COMPONENTS OF WHEEL ARMS FOR ELI WINDMILLS. HISTORIC DEBRIS FROM PUNCHING WORK IS VISIBLE BENEATH THE MACHINE IN THE OPERATOR'S PIT.' ON THE LEFT IS A U-SHAPED LOVEJOY FIELD PUNCH FOR USE IN INSTALLING STEEL WINDMILL/TOWER COMPONENTS. - Kregel Windmill Company Factory, 1416 Central Avenue, Nebraska City, Otoe County, NE

  19. Effect of Rivet Pitch upon the Fatigue Strength of Single-row Riveted Joints of 0.025- to 0.025-inch 24S-T Alclad

    NASA Technical Reports Server (NTRS)

    Seliger, Victor

    1943-01-01

    S-N curves at the range ratio of 0.2 were experimentally obtained for each of the following values of rivet pitch P as used in a single-row lap joint of 0.025- to 0.025-inch 24S-T alclad with one-eight AN430 round-head rivets: p=0.5, 0.75, 1.0, 1.5. Families of constant rivet pitch curves, which define the fatigue life for specimens studied, were developed. Curves showing the variation of the effective stress concentration factor in fatigue with rivet pitch and maximum load per rivet were also established.

  20. Results of uniaxial and biaxial tests on riveted fuselage lap joint specimens

    NASA Technical Reports Server (NTRS)

    Vlieger, H.

    1994-01-01

    As part of an FAA-NLR collaborative program on structural integrity of aging aircraft, NLR carried out uniaxial and biaxial fatigue tests on riveted lap joint specimens being representative for application in a fuselage. All tests were constant amplitude tests with maximum stresses being representative for fuselage pressurization cycles and R-values of 0.1. The parameters selected in the testing program were the stress level (sigma(sub max) = 14 and 16 ksi) and the rivet spacing (0.75 and 1.0 inch). All specimens contained 3 rows of countersunk rivets, the rivet row spacing was 1 inch and the rivet orientation continuous.

  1. Laboratory and workplace assessments of rivet bucking bar vibration emissions.

    PubMed

    McDowell, Thomas W; Warren, Christopher; Xu, Xueyan S; Welcome, Daniel E; Dong, Ren G

    2015-04-01

    Sheet metal workers operating rivet bucking bars are at risk of developing hand and wrist musculoskeletal disorders associated with exposures to hand-transmitted vibrations and forceful exertions required to operate these hand tools. New bucking bar technologies have been introduced in efforts to reduce workplace vibration exposures to these workers. However, the efficacy of these new bucking bar designs has not been well documented. While there are standardized laboratory-based methodologies for assessing the vibration emissions of many types of powered hand tools, no such standard exists for rivet bucking bars. Therefore, this study included the development of a laboratory-based method for assessing bucking bar vibrations which utilizes a simulated riveting task. With this method, this study evaluated three traditional steel bucking bars, three similarly shaped tungsten alloy bars, and three bars featuring spring-dampeners. For comparison the bucking bar vibrations were also assessed during three typical riveting tasks at a large aircraft maintenance facility. The bucking bars were rank-ordered in terms of unweighted and frequency-weighted acceleration measured at the hand-tool interface. The results suggest that the developed laboratory method is a reasonable technique for ranking bucking bar vibration emissions; the lab-based riveting simulations produced similar rankings to the workplace rankings. However, the laboratory-based acceleration averages were considerably lower than the workplace measurements. These observations suggest that the laboratory test results are acceptable for comparing and screening bucking bars, but the laboratory measurements should not be directly used for assessing the risk of workplace bucking bar vibration exposures. The newer bucking bar technologies exhibited significantly reduced vibrations compared to the traditional steel bars. The results of this study, together with other information such as rivet quality, productivity, tool

  2. Laboratory and Workplace Assessments of Rivet Bucking Bar Vibration Emissions

    PubMed Central

    McDowell, Thomas W.; Warren, Christopher; Xu, Xueyan S.; Welcome, Daniel E.; Dong, Ren G.

    2016-01-01

    Sheet metal workers operating rivet bucking bars are at risk of developing hand and wrist musculoskeletal disorders associated with exposures to hand-transmitted vibrations and forceful exertions required to operate these hand tools. New bucking bar technologies have been introduced in efforts to reduce workplace vibration exposures to these workers. However, the efficacy of these new bucking bar designs has not been well documented. While there are standardized laboratory-based methodologies for assessing the vibration emissions of many types of powered hand tools, no such standard exists for rivet bucking bars. Therefore, this study included the development of a laboratory-based method for assessing bucking bar vibrations which utilizes a simulated riveting task. With this method, this study evaluated three traditional steel bucking bars, three similarly shaped tungsten alloy bars, and three bars featuring spring-dampeners. For comparison the bucking bar vibrations were also assessed during three typical riveting tasks at a large aircraft maintenance facility. The bucking bars were rank-ordered in terms of unweighted and frequency-weighted acceleration measured at the hand-tool interface. The results suggest that the developed laboratory method is a reasonable technique for ranking bucking bar vibration emissions; the lab-based riveting simulations produced similar rankings to the workplace rankings. However, the laboratory-based acceleration averages were considerably lower than the workplace measurements. These observations suggest that the laboratory test results are acceptable for comparing and screening bucking bars, but the laboratory measurements should not be directly used for assessing the risk of workplace bucking bar vibration exposures. The newer bucking bar technologies exhibited significantly reduced vibrations compared to the traditional steel bars. The results of this study, together with other information such as rivet quality, productivity, tool

  3. The fatigue strength of riveted joints and lugs

    NASA Technical Reports Server (NTRS)

    Schijve, J

    1956-01-01

    This report deals with a number of tests on riveted joints and lugs for the primary purpose of comparing the several types of riveted joints and to study the effect of various factors on the fatigue strength of lugs. A check was made to ascertain whether or not an estimate of the fatigue life at a certain loading could be made from the dimensions of the joint and the fatigue data of the unnotched materials. Recommendations are made on the proportioning of joints to obtain better fatigue behavior.

  4. Self-Pierce Riveting of Three Aluminium Alloy and Mild Steel Sheets

    SciTech Connect

    Mori, K.; Abe, Y.; Sakai, S.; Kato, T.

    2010-06-15

    Three aluminium alloy and steel sheets were joined with a self-piercing rivet. Self-pierce riveting has the function of joining steel and aluminium alloys having very different melting points due to plastic joining. The requisites for joining the three sheets are the driving of the rivet leg through the middle sheet, the flaring of the rivet leg in the lower sheet and the prevention of the fracture of the lower sheet. The joinability for various combinations of the three sheets was determined. When the rivet leg is small, no driving through the middle sheet occurs, the lower sheet ruptures for a large rivet leg. In addition, 980 MPa high strength steel, mild steel and aluminium alloy sheets were joined by the self-pierce riveting.

  5. Fatigue crack initiation in riveted lap joints and in pressurized fuselages

    NASA Astrophysics Data System (ADS)

    Mueller, Richard P. G.

    1993-06-01

    Riveted joints in pressurized fuselages are exposed to severe fatigue loading. The study was carried out to increase fundamental understanding of the behavior of riveted fuselage joints. Areas of interest include rivet flexibility, load transfer, residual stress distribution, fatigue crack location, secondary bending and inter-sheet friction. These aspects depend on the squeezing force used to drive the rivet. Flat uniaxially loaded riveted lap joint specimens show longer fatigue lives than curved riveted panels loaded by internal pressure in a barrel test setup. Strain gauge measurements on a barrel test setup show more severe loading of the non-countersunk inner sheet compared to the countersunk outer sheet. Finite element calculations gave insight to the improved fatigue crack initiation performance for increased sqeezing force and to the crack initiation location. The early crack initiation at the edges of flat riveted lap joint panels is explained.

  6. Self-Pierce Riveting of Three Aluminium Alloy and Mild Steel Sheets

    NASA Astrophysics Data System (ADS)

    Mori, K.; Abe, Y.; Kato, T.; Sakai, S.

    2010-06-01

    Three aluminium alloy and steel sheets were joined with a self-piercing rivet. Self-pierce riveting has the function of joining steel and aluminium alloys having very different melting points due to plastic joining. The requisites for joining the three sheets are the driving of the rivet leg through the middle sheet, the flaring of the rivet leg in the lower sheet and the prevention of the fracture of the lower sheet. The joinability for various combinations of the three sheets was determined. When the rivet leg is small, no driving through the middle sheet occurs, the lower sheet ruptures for a large rivet leg. In addition, 980 MPa high strength steel, mild steel and aluminium alloy sheets were joined by the self-pierce riveting.

  7. 5. STANDPIPE STRUCTURE DETAIL SHOWING CONNECTIONS TO PENSTOCKS, RIVETED SECTIONAL ...

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

    5. STANDPIPE STRUCTURE DETAIL SHOWING CONNECTIONS TO PENSTOCKS, RIVETED SECTIONAL CONSTRUCTION OF TWO OF THE THREE ORIGINAL STANDPIPES (PHOTO RIGHT), WELDED SECTIONAL CONSTRUCTION OF FOURTH STANDPIPE, AND MODERN VENTILATION VALVES ON FIFTH PENSTOCK AT PHOTO LEFT CENTER BETWEEN FOURTH STANDPIPE AND ORIGINAL TWO. VIEW TO NORTHEAST. - Big Creek Hydroelectric System, Powerhouse 3 Penstock Standpipes, Big Creek, Big Creek, Fresno County, CA

  8. 16. View of riveted gusset plate connection between compression diagonal, ...

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

    16. View of riveted gusset plate connection between compression diagonal, tension diagonal, and lateral brace at center of 4th panel from north end of west truss of north span, looking from the east - Bridge No. 4900, Spanning Root River at Trunk Highway 16, Rushford, Fillmore County, MN

  9. Multicrack growth monitoring at riveted lap joints using piezoelectric patches

    NASA Astrophysics Data System (ADS)

    Ihn, Jeong-Beom; Chang, Fu-Kuo

    2002-06-01

    A built-in cost-effective diagnostic system is being developed to monitor fatigue crack growth in aircraft structures. The proposed system consists of a SMART Layer by Acellent Technologies with an embedded network of distributed piezoelectric sensors/actuators, a diagnostic unit, and software. Multi-riveted aluminum lap joints (936 x 462 mm) were tested for a constant amplitude fatigue test under tensile loading to monitor crack growth at rivet holes. A SMART Layer was designed as a strip and surface-mounted to the critical area of lap joints where crack initiation and growth were suspected. The SMART Layer installed between the two rivet rows was used as an actuator strip and the other layer located below the rivets was used as a sensor strip. Using the software, pre-selected diagnostic signals from a designated piezoelectric actuator to its neighboring sensors were generated by the diagnostic unit. A corresponding sensor signals were recorded and compared to a previously recorded baseline reference. The signal processing technique and interpretation algorithm were developed and implemented for extracting features related to crack growth condition at the time of measurement. The results of estimates were compared with non-destructive testing (NDT) data taken from the experiments, which were conducted during the course of the investigation. The probability of damage detection, compared to conventional NDT techniques, was evaluated.

  10. Contact analysis for riveted and bolted joints of composite laminates

    NASA Astrophysics Data System (ADS)

    Ye, Tian-Qi; Li, Wei; Shen, Guanqing

    The computational strategy and numerical technique developed are demonstrated to be efficient for the analysis of riveted and bolted joints of composite laminates. The 3D contact analysis provides more accurate results for the evaluation of strength of the mechanically fastened joints in the composite structures. The method described can be extended to multibody contact problems, it has been implemented in the computer codes.

  11. Detail of south granite pier revealing riveted truss ends and ...

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

    Detail of south granite pier revealing riveted truss ends and iron footing plates on top of granite cap stones. View north - New York, New Haven & Hartford Railroad, Fort Point Channel Rolling Lift Bridge, Spanning Fort Point Channel, Boston, Suffolk County, MA

  12. Retention of riveted aluminum leg bands by wild turkeys

    USGS Publications Warehouse

    Diefenbach, Duane R.; Vreeland, Wendy C.; Casalena, Mary Jo; Schiavone, Michael V.

    2016-01-01

    In order for mark–recapture models to provide unbiased estimates of population parameters, it is critical that uniquely identifying tags or marks are not lost. We double-banded male and female wild turkeys with aluminum rivet bands and estimated the probability that a bird would be recovered with both bands <1–225 wk since banding (mean = 51.2 wk, SD = 44.0). We found that 100% of females (n = 37) were recovered with both bands. For males, we recovered 6 of 188 turkeys missing a rivet band for a retention probability of 0.984 (95% CI = 0.96–0.99). If male turkeys are double-banded with rivet bands the probability of recovering a turkey without any marks is <0.001. We failed to detect a change in band retention over time or differences between adults and juveniles. Given the low cost and high retention rates of rivet aluminum bands, we believe they are an effective marking technique for wild turkeys and, for most studies, will minimize any concern about the assumption that marks are not lost.

  13. View of riveted joint on tower support superstructure of Tensaw ...

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

    View of riveted joint on tower support superstructure of Tensaw River Bridge truss No. 2, looking southwest, showing deflector sheaves, roller and complex joint construction - Tensaw River Lift Bridge, Spanning Tensaw River at U.S. Highway 90, Mobile, Mobile County, AL

  14. View of riveted joint on tower support superstructure of Tensaw ...

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

    View of riveted joint on tower support superstructure of Tensaw River Bridge truss No. 2, looking northeast, showing deflector sheaves, roller and complex joint construction - Tensaw River Lift Bridge, Spanning Tensaw River at U.S. Highway 90, Mobile, Mobile County, AL

  15. 49 CFR 230.34 - Riveted repairs and alterations.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION STEAM LOCOMOTIVE INSPECTION AND MAINTENANCE STANDARDS Boilers and... portions of the boiler. Prior to making riveted alterations on unstayed portions of the boiler, the steam... standard for boiler repairs. The steam locomotive owner and/or operator shall satisfy...

  16. 14. View northeast. Detail of typical fish plating, riveted to ...

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

    14. View northeast. Detail of typical fish plating, riveted to top flange at center of each span. Same detail is found at center of both lower chords. - Walpole-Westminster Bridge, Spanning Connecticut River between Walpole, NH & Westminster, VT, Walpole, Cheshire County, NH

  17. Acoustical Evaluation of Bucking Bars during Riveting Operations in Bldg 9001, Tinker AFB, Oklahoma

    DTIC Science & Technology

    2013-11-14

    impact noise, bucking bar, riveting, hearing, acoustics, noise, sound pressure level, equivalent continuous level 16. SECURITY CLASSIFICATION OF: 17...FORCE USAF SCHOOL OF AEROSPACE MEDICINE (AFMC) WRIGHT-PATTERSON AFB OH 14 November 2013 MEMORANDUM FOR 72 AMDS /SGPB ATTN: LT COL JEFFREY...OEC), at the request of 72 AMDS /SGPB, conducted an acoustical evaluation of nine different rivet bucking bars during three separate riveting

  18. Strength distributions of adhesive bonded and adhesive/rivet combined joints

    NASA Astrophysics Data System (ADS)

    Imanaka, Makoto; Haraga, Kosuke; Nishikawa, Tetsuya

    1992-11-01

    The tensile and shear strengths of adhesive and adhesive/rivet combined joints are statistically evaluated, and the probability of failure is calculated for these two types of joints. Attention is given to the effects of the adhesive/rivet combination on mean tensile shear strength and coefficient of variation. The adhesive joint's strength distribution was well approximated by Weibull or doubly-exponential distribution function; tensile shear strength is significantly improved by the combination with rivets.

  19. Stress-intensity factor solutions for cracks at countersunk rivet holes under uniaxial tension

    NASA Astrophysics Data System (ADS)

    Tan, P. W.; Bigelow, C. A.; Odonoghue, P. E.; Atluri, S. N.

    1994-02-01

    To predict crack growth and fracture strengths of riveted joints subjected to widespread fatigue damage, accurate stress and fracture analyses of corner and surface cracks at a rivet hole are needed. The results presented in this report focus on the computation of stress-intensity factor solutions for rivet holes with cracks. The stress-intensity factor solutions for surface and corner cracks at countersunk rivet holes in a plate were obtained using the finite-element-alternating technique. A range of crack shapes, crack sizes, and crack locations under remote tension were considered.

  20. Quantitative investigation of surface and subsurface fatigue cracks near rivets in riveted joints using acoustic, electron and optical microscopy

    NASA Astrophysics Data System (ADS)

    Connor, Zayna Marie

    2000-10-01

    Using scanning acoustic microscopy, optical microscopy and scanning electron microscopy, in conjunction with fractography of fractured surfaces, the crack formation and growth kinetics of subsurface fatigue cracks and surface breaking fatigue cracks near rivets have been characterized in detail in this research. The scanning acoustic microscope was used to quantitatively investigate subsurface fatigue cracks (even when they were very small) at and near countersunk rivets in riveted lap joint specimens that are similar to the riveted lap joints found in the fuselages of many aircraft. It was found that the maximum nominal applied stress influences the fatigue crack initiation and propagation behavior. Eyebrow type cracks develop at lower stresses and centerline cracks develop at higher stresses. At low stress ranges, the fatigue cracks initiate a short distance from the rivet at or near the hidden surface of the chamfered panel. At higher stress amplitudes, the cracks initiate at the blunt knife edge. Residual compressive stresses and fretting are suggested to play more important roles at lower stress ranges. Both types of cracks initiate in a shear mode but transform to tensile, mode I, cracks as they grow. This transition occurs much more rapidly at the higher stress amplitude. At both high and low stresses, the cracks are longer on the fayed surface of the panel than elsewhere. In a comparison of Alclad 2024-T3 and Alclad 2524-T3, it was found that the high purity aluminum alloy 2524 nucleates cracks at a greater number of cycles than the less pure aluminum alloy 2024. At high stress, crack initiation plays less of a roll and the 2024 alloy has a longer life. The scanning acoustic microscope enabled us to study subsurface fatigue cracks. The understanding gained from the characterization of the subsurface fatigue cracks will help in the modeling of crack initiation and growth in the riveted lap joint and will also aid in the improvement of NDE techniques for the

  1. Thermographic inspection of fatigue cracks in riveted plates

    NASA Astrophysics Data System (ADS)

    Welch, Christopher S.; Cramer, K. E.; Dawicke, David S.

    A theoretical and experimental analysis of the inspection of reiveted plates using the thermoelastic effect is presented. Theoretically, a model is employed to estimate the thermoelastic response expected from a cracked and uncracked rivet hole. The stress invariant, which causes the thermoelastic response, is calculated for the cracked case using an FEM model and for the uncracked case using a theoretical approximation. The differences in the two thermal responses are reduced when the effects of optical spatial averaging, thermal conduction, and a concentric blind area representing the rivet heat are considered. It is suggested that discrimination between the cracked and uncracked cases for short cracks will improve with increasing frequency of stress oscillation. Measurements are shown for aerospace aluminum samples with and without fatigue cracks propagating from holes in a plate. The effect of mean stress on the thermoelastic response is illustrated, and the results are qualitatively compared with the finite element analysis.

  2. Evaluation and Handbook Data of 7050 Rivets. Volume 1

    DTIC Science & Technology

    1981-12-01

    343) 53.1 (366) 7/32 (5.5) 46.1 (318) 49.6 (342) 47.1 (325) 50.3 ( 347 ) 49.6 (342) 52.7 (363) 1/4 (6.3) 42.9 (296 45.6 (314) 44.5 (307) 46.1 (318...46.7 (322) 48.4 (333) 9/32 (7.1) 43.4 (299) 46.6 (321) 46.5 (321) 50.0 (345) 50.4 ( 347 ) 52.9 (365) 5/16 (7.9) 43.3 (298) 44.9 (308) 43.2 (298) 45.0 (310...of sheet material at countersink "F of Rivet" indicates failure of Rivet 73 9- o LU 4-U Lcv, %0 zz WEJ U -t; - -- 𔃽 I2-- - t .2W- 7F74 LI.- W 0) C

  3. The Alcoa ram fastener: A reusable blind rivet

    NASA Technical Reports Server (NTRS)

    Dewalt, W. J.

    1972-01-01

    Results of tensile, shear, fatigue and accelerated weathering tests are presented for the ram fastener, a reusable, single unit blind rivet. The effects of variations in hole size, grip length and sheet thickness on strength properties of the fastener were determined. The test results show these fasteners to have strength characteristics suitable for light structural applications. Exposure to accelerated weathering did not impair their performance.

  4. Experimental detection of cracks at rivets using structural wave propagation

    NASA Astrophysics Data System (ADS)

    Fromme, Paul; Sayir, Mahir B.

    2001-04-01

    Guided bending waves are used to detect defects in aluminum plates. The scattered field of a notched hole is studied as a model for a crack at a rivet hole in an airplane fuselage. The first anti-symmetric Lamb wave mode is excited using piezoelectric transducers. The scattered field is measured with a heterodyne laser-interferometer. Good agreement between measurements and an analytical model was found. A small notch changes the scattered field and can be detected.

  5. The Relative Hydrodynamic Resistance of Various Types of Rivet Heads from Tests of Planning Surfaces, Special Report

    NASA Technical Reports Server (NTRS)

    Truscott, Starr; Parksinson, John B.

    1935-01-01

    The Committee was requested to investigate the effect of various types of rivet heads on hydrodynamic resistance. The proposal was made to obtain the resistance of the various types of rivets by tests of planing surfaces on which the full size rivets would be arranged. The testing methods, results and conclusions are given.

  6. 46 CFR 126.160 - Tests and inspections during repairs or alterations, or during riveting, welding, burning, or...

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... during riveting, welding, burning, or other hot work. 126.160 Section 126.160 Shipping COAST GUARD... § 126.160 Tests and inspections during repairs or alterations, or during riveting, welding, burning, or... riveting, welding, burning, or other hot work may commence. (c) Each examination must be conducted...

  7. Influence of Micro-Rivet Manufacturing Process on Quality of Micro-Joint

    NASA Astrophysics Data System (ADS)

    Presz, Wojciech; Cacko, Robert

    2011-05-01

    One of the modern industry endeavors is to be able to manufacture smaller size components using traditional or new technologies. Smaller components usually need special assembly techniques. New course of mechanical joining improvement is to develop process modification for decreased scale, i.e. micro-joining. Very interesting problems arise with self-piercing riveting (SPR) method, because one of the factors influencing SPR joint strength is rivet material properties. Rivet production by forming produces certain distribution of stress/strain field within cross-section of a rivet, influencing the process of SPR joint formation in micro-joining. Results of initial analysis of micro-joint strength are presented in the paper. Stress/strain field obtained during rivet production is taken into account in numerical simulation of micro-riveting process. Joint loading test was numerically modeled. Simulations consisted of three phases: manufacturing of the rivet, forming a joint and strength test. Stress strain fields were superimposed over the joint on every stage. Influence of the manufacturing method of the rivet on the joint quality and strength was observed. The commercial FEM software MSC-Marc is used for numerical simulations.

  8. Effect of aging on mechanical properties of aluminum-alloy rivets

    NASA Technical Reports Server (NTRS)

    Roop, Frederick C

    1941-01-01

    Curves and tabular data present the results of strength tests made during and after 2 1/2 years of aging on rivets and rivet wire of 3/16-inch nominal diameter. The specimens were of aluminum alloy: 24s, 17s, and a17s of the duralumin type and 53s of the magnesium-silicide type.

  9. Effect of aging on mechanical properties of aluminum-alloy rivets

    NASA Technical Reports Server (NTRS)

    Roop, Frederick C

    1941-01-01

    Curves and tabular data present the results of strength tests made during and after 2 1/2 years of aging on rivets and rivet wire of 3/16-inch nominal diameter. The specimens were of aluminum alloy: 24S, 17S, and A17S of the duralumin type and 53S of the magnesium-silicide type.

  10. Laboratory and field measurements and evaluations of vibration at the handles of riveting hammers.

    PubMed

    McDowell, Thomas W; Warren, Christopher; Welcome, Daniel E; Dong, Ren G

    2012-10-01

    The use of riveting hammers can expose workers to harmful levels of hand-transmitted vibration (HTV). As a part of efforts to reduce HTV exposures through tool selection, the primary objective of this study was to evaluate the applicability of a standardized laboratory-based riveting hammer assessment protocol for screening riveting hammers. The second objective was to characterize the vibration emissions of reduced vibration riveting hammers and to make approximations of the HTV exposures of workers operating these tools in actual work tasks. Eight pneumatic riveting hammers were selected for the study. They were first assessed in a laboratory using the standardized method for measuring vibration emissions at the tool handle. The tools were then further assessed under actual working conditions during three aircraft sheet metal riveting tasks. Although the average vibration magnitudes of the riveting hammers measured in the laboratory test were considerably different from those measured in the field study, the rank orders of the tools determined via these tests were fairly consistent, especially for the lower vibration tools. This study identified four tools that consistently exhibited lower frequency-weighted and unweighted accelerations in both the laboratory and workplace evaluations. These observations suggest that the standardized riveting hammer test is acceptable for identifying tools that could be expected to exhibit lower vibrations in workplace environments. However, the large differences between the accelerations measured in the laboratory and field suggest that the standardized laboratory-based tool assessment is not suitable for estimating workplace riveting hammer HTV exposures. Based on the frequency-weighted accelerations measured at the tool handles during the three work tasks, the sheet metal mechanics assigned to these tasks at the studied workplace are unlikely to exceed the daily vibration exposure action value (2.5 m s(-2)) using any of the

  11. A finite element and experimental investigation on the fatigue of riveted lap joints in aircraft applications

    NASA Astrophysics Data System (ADS)

    Atre, Amarendra

    Aircraft fuselage skin panels are joined together by rivets. The initiation and propagation of fatigue cracks in aircraft structures at and around the rivet/skin interface is directly related to residual stress field induced during the riveting process and subsequent service loads. Variations in the manufacturing process, such as applied loading and presence of sealant can influence the induced residual stress field. In previous research, the riveting process has been simulated by a 2D axisymmetric force-controlled analysis. The 2D analysis cannot capture the unsymmetrical residual stress state resulting from process variations. Experimental work has also been limited to observing effects of squeeze force on fatigue crack initiation in the riveted lap joint. In this work, a 3D finite element model of the riveting process that incorporates plasticity and contact between the various surfaces is simulated using ABAQUS finite element code to capture the residual stress state at the rivet/skin interface. The finite element model is implemented to observe the effects of interference, sealant and hole quality on the residual stress state using Implicit and Explicit solvers. Effects of subsequent load transfer are also analyzed with the developed model. A set of controlled lap joint fatigue experiments for the different conditions provides validation to the model.

  12. Effects of process parameters on friction self-piercing riveting of dissimilar materials

    SciTech Connect

    Liu, Xun; Lim, Yong Chae; Li, Yongbing; Tang, Wei; Ma, Yunwu; Feng, Zhili; Ni, Jun

    2016-05-24

    In the present work, a recently developed solid state joining technique, Friction self-piercing riveting (F-SPR), has been applied for joining high strength aluminum alloy AA7075-T6 to magnesium alloy AZ31B. The process was performed on a specially designed machine where the spindle can achieve the motion of sudden stop. Effects of rivet rotating rate and punch speed on axial plunge force, torque, joint microstructure and quality have been analyzed systematically. During F-SPR, higher rotating rate and slower punch speed can reduce axial force and torque, which correspondingly results in a slightly smaller interlock between rivet leg and joined materials. Improved local flowability of both aluminum and magnesium alloys under a higher rotating speed results in a thicker aluminum layer surrounding the rivet leg, where formation of Al-Mg intermetallics was observed. Equivalent joint strength obtained in this study are higher than the yield strength of the AZ31 Mg alloy. One of the tensile failure modes is the rivet fracture, which is due to local softening of rivet leg from frictional heat. Lastly, other two failure modes include rivet pullout and shear through of bottom sheet.

  13. Effects of process parameters on friction self-piercing riveting of dissimilar materials

    DOE PAGES

    Liu, Xun; Lim, Yong Chae; Li, Yongbing; ...

    2016-05-24

    In the present work, a recently developed solid state joining technique, Friction self-piercing riveting (F-SPR), has been applied for joining high strength aluminum alloy AA7075-T6 to magnesium alloy AZ31B. The process was performed on a specially designed machine where the spindle can achieve the motion of sudden stop. Effects of rivet rotating rate and punch speed on axial plunge force, torque, joint microstructure and quality have been analyzed systematically. During F-SPR, higher rotating rate and slower punch speed can reduce axial force and torque, which correspondingly results in a slightly smaller interlock between rivet leg and joined materials. Improved localmore » flowability of both aluminum and magnesium alloys under a higher rotating speed results in a thicker aluminum layer surrounding the rivet leg, where formation of Al-Mg intermetallics was observed. Equivalent joint strength obtained in this study are higher than the yield strength of the AZ31 Mg alloy. One of the tensile failure modes is the rivet fracture, which is due to local softening of rivet leg from frictional heat. Lastly, other two failure modes include rivet pullout and shear through of bottom sheet.« less

  14. Modeling growth of fatigue cracks which originate at rivet holes

    NASA Technical Reports Server (NTRS)

    Mear, Mark E.

    1989-01-01

    When a structural component is subjected to repeated stress cycles, it can fail at stresses which are well below the tensile strength of the material. The processes leading to this failure are termed fatigue. Instances of fatigue failure in aircraft have become an increasing concern. The crack leading to failure often originate at rivet holes and then grow in response to stress cycles which occur during the operation of the aircraft. A necessary step to preventing failures in todays fleet of aging aircraft is to increase the frequency and quality of inspections; steps were already taken in this direction. There is also a need for modeling of fatigue crack growth in the aircraft structures so that improvements in design can be established and predictions of the life of the components can be made. The purpose is to provide a method to accurately predict the growth of fatigue cracks and to use this method to make predictions about the life of aircraft structural components. The method relies on the formulation and numerical solution of a singular integral equation(s) for an arbitrarily shaped crack(s) which propagate in response to the applied loading. Of special interest to the aging aircraft studies are cracks which originate at circular holes (i.e., rivet holes), but other crack geometries can be treated equally as well.

  15. A robust multi-frequency mixing algorithm for suppression of rivet signal in GMR inspection of riveted structures

    NASA Astrophysics Data System (ADS)

    Safdernejad, Morteza S.; Karpenko, Oleksii; Ye, Chaofeng; Udpa, Lalita; Udpa, Satish

    2016-02-01

    The advent of Giant Magneto-Resistive (GMR) technology permits development of novel highly sensitive array probes for Eddy Current (EC) inspection of multi-layer riveted structures. Multi-frequency GMR measurements with different EC pene-tration depths show promise for detection of bottom layer notches at fastener sites. However, the distortion of the induced magnetic field due to flaws is dominated by the strong fastener signal, which makes defect detection and classification a challenging prob-lem. This issue is more pronounced for ferromagnetic fasteners that concentrate most of the magnetic flux. In the present work, a novel multi-frequency mixing algorithm is proposed to suppress rivet signal response and enhance defect detection capability of the GMR array probe. The algorithm is baseline-free and does not require any assumptions about the sample geometry being inspected. Fastener signal suppression is based upon the random sample consensus (RANSAC) method, which iteratively estimates parameters of a mathematical model from a set of observed data with outliers. Bottom layer defects at fastener site are simulated as EDM notches of different length. Performance of the proposed multi-frequency mixing approach is evaluated on finite element data and experimental GMR measurements obtained with unidirectional planar current excitation. Initial results are promising demonstrating the feasibility of the approach.

  16. Three-dimensional finite element analyses of the local mechanical behavior of riveted lap joints

    NASA Astrophysics Data System (ADS)

    Iyer, Kaushik Arjunan

    Three-dimensional elastic-plastic finite element models of single and double rivet-row lap joints have been developed to evaluate local distortions and the mechanics of airframe-type 7075-T6 aluminum alloy riveted assemblies. Loading induced distortion features such as the excess assembly compliance, rivet tilt, local in- and out-of-plane slips and stress concentration factors are evaluated as functions of rivet countersinking, rivet material and friction coefficient. Computed features are examined to identify alterations in the proportions of in-plane and out-of-plane load transmission across rivet-panel interfaces and isolate global and lower-order effects present in the complex response of these multi-body assemblies. Analytical procedures are validated by comparing calculated and measured values of excess assembly compliance and local panel bending. Direct out-of-plane load transmission between the rivet heads and panels affects global deformation features such as remote panel bending and local features such as the panel stress concentration factor. The increase in stress concentration due to panel bending is self-limiting owing to decreasing in-plane load bearing with increasing rivet tilt, which is a composite reflection of the basic rivet deformation modes of shear and rotation. Calculations have also been performed to define approximate steady-state fretting fatigue conditions that lead to crack initiation at a panel hole surface in single and double rivet-row assemblies for countersunk and non-countersunk rivets. These account for and isolate effects of interference and clamping forces on fatigue performance by comparing computed circumferential variations of bulk residual stresses, cyclic stress range and mean stress. With interference, a non-countersunk assembly is shown to be as prone to crack initiation as a countersunk assembly. Frictional work due to fretting is evaluated and the physical location of fretting fatigue crack initiation is predicted by

  17. Vibration reduction of pneumatic percussive rivet tools: mechanical and ergonomic re-design approaches.

    PubMed

    Cherng, John G; Eksioglu, Mahmut; Kizilaslan, Kemal

    2009-03-01

    This paper presents a systematic design approach, which is the result of years of research effort, to ergonomic re-design of rivet tools, i.e. rivet hammers and bucking bars. The investigation was carried out using both ergonomic approach and mechanical analysis of the rivet tools dynamic behavior. The optimal mechanical design parameters of the re-designed rivet tools were determined by Taguchi method. Two ergonomically re-designed rivet tools with vibration damping/isolation mechanisms were tested against two conventional rivet tools in both laboratory and field tests. Vibration characteristics of both types of tools were measured by laboratory tests using a custom-made test fixture. The subjective field evaluations of the tools were performed by six experienced riveters at an aircraft repair shop. Results indicate that the isolation spring and polymer damper are very effective in reducing the overall level of vibration under both unweighted and weighted acceleration conditions. The mass of the dolly head and the housing played a significant role in the vibration absorption of the bucking bars. Another important result was that the duct iron has better vibration reducing capability compared to steel and aluminum for bucking bars. Mathematical simulation results were also consistent with the experimental results. Overall conclusion obtained from the study was that by applying the design principles of ergonomics and by adding vibration damping/isolation mechanisms to the rivet tools, the vibration level can significantly be reduced and the tools become safer and user friendly. The details of the experience learned, design modifications, test methods, mathematical models and the results are included in the paper.

  18. Self-Pierce Riveting Through 3 Sheet Metal Combinations

    NASA Astrophysics Data System (ADS)

    Andersson, Roger; Jonason, Paul; Pettersson, Tommy

    2011-05-01

    One way to reduce the CO2 emissions in automotives is to reduce the weight of the Body-In-White. One easy to achieve the weight reduction is to replace steel sheet materials with Al alloys, which is 3 times lighter. One issue is the joining process, especially with combinations between steel grades and AL alloys. Example of combination of mixed material combinations (Al-steel) might be found in the door structure. The reason is because of the AL alloys worthier crash performance so the automotive manufacturer might want to use crash impact beams made by high strength steels in a AL intensive door structure. The joining process between aluminum and steel are problematic due it's not possible to use traditional spot-welding technologies due to the materials total difference in microstructure characteristics as well thermal properties. To overcome this issue then mechanical as well adhesion joining are frequently used. This paper describes a development process and subsequently analysis of a self-pierce rivet (SPR) process between 3 sheet metal combinations. The multi-material combinations in this study were a combination of ultra high strength steels sheets (DP1000) and a Al-alloy (AA 6014). The analysis of the SPR process, in sense of mechanical strengths, has been done by peel- and shear tests. To reduce the amount of future physical tests a virtual FE-model has been developed for the process. This FE model of the process has been subsequently used to analyze the mechanical strength during plastic deformation. By using inverse analysis a correct contact algorithm has been evaluated that would predict the binding force between the rivet and sheet under a deformation process. With this new virtual model it will not only possible to analyze and develop the SPR process but also to achieve the final strength of the joint.

  19. Self-Pierce Riveting Through 3 Sheet Metal Combinations

    SciTech Connect

    Andersson, Roger; Jonason, Paul; Pettersson, Tommy

    2011-05-04

    One way to reduce the CO{sub 2} emissions in automotives is to reduce the weight of the Body-In-White. One easy to achieve the weight reduction is to replace steel sheet materials with Al alloys, which is 3 times lighter. One issue is the joining process, especially with combinations between steel grades and AL alloys. Example of combination of mixed material combinations (Al-steel) might be found in the door structure. The reason is because of the AL alloys worthier crash performance so the automotive manufacturer might want to use crash impact beams made by high strength steels in a AL intensive door structure. The joining process between aluminum and steel are problematic due it's not possible to use traditional spot-welding technologies due to the materials total difference in microstructure characteristics as well thermal properties. To overcome this issue then mechanical as well adhesion joining are frequently used. This paper describes a development process and subsequently analysis of a self-pierce rivet (SPR) process between 3 sheet metal combinations. The multi-material combinations in this study were a combination of ultra high strength steels sheets (DP1000) and a Al-alloy (AA 6014). The analysis of the SPR process, in sense of mechanical strengths, has been done by peel- and shear tests. To reduce the amount of future physical tests a virtual FE-model has been developed for the process. This FE model of the process has been subsequently used to analyze the mechanical strength during plastic deformation. By using inverse analysis a correct contact algorithm has been evaluated that would predict the binding force between the rivet and sheet under a deformation process. With this new virtual model it will not only possible to analyze and develop the SPR process but also to achieve the final strength of the joint.

  20. Novel tnpR-based transposable promoter traps suitable for RIVET studies in different gram-negative bacteria.

    PubMed

    Lozano, Mauricio J; Salas, María Eugenia; Giusti, María de los Angeles; Martini, María Carla; López, José Luis; Salto, Ileana; Del Papa, María Florencia; Pistorio, Mariano; Lagares, Antonio

    2013-04-01

    The preparation of plasmid-borne RIVET libraries can be troublesome when high genomic coverages are needed. We present here the construction and functional validation of a new set of miniTn5 promoter traps to generate tnpR-based RIVET libraries. The ability to generate tnpR transcriptional fusions by transposition will significantly facilitate the setup of RIVET studies in those bacteria where Tn5 transposition is operative.

  1. Mechanical joining with self piercing solid-rivets at elevated tool velocities

    SciTech Connect

    Neugebauer, R.; Jesche, F.; Kraus, C.; Hensel, S.

    2011-05-04

    In the present paper the influence of a higher setting velocity in the joining process of self piercing solid-rivets is shown. In the conventional process tool velocities well below 1 m/s are common. The present research results show the potential of increasing them in the range of about 5 m/s. The results are especially relevant for joining high-strength steels. These steel sheets often cause problems in the process of riveting mixed materials, e. g. aluminium-steel compound. The high strength of the steel sometimes leads to undesirable material flow in the joining process or unwanted burr development. These effects, which are described in detail in the article, can be reduced significantly for the investigated cases by the use of higher tool velocities. Using a high speed camera and a load cell, a test setup based on a drop tower was realized. It was used to time the force signals and the motion profile of the high speed riveting process. The results of the force analysis show an oscillating force progression. Within a numerical research the principal effects influencing the results of the riveting process can be shown. It was found that the pulse-like force transmission between riveting machine and punch, results in various vibrations especially of long and thin tool parts. Hence the rivet penetrates the sheet metal with non-uniform velocities. As a result the early indentation of die into the lower sheet metal at the beginning of the process is reduced, so that the final process step provides a sufficient material flow into the circular rivet groove. A strain-rate dependent process model with elastic tool properties and consideration of inertia effects is presented.

  2. The Increase in Frictional Resistance Caused by Various Types of Rivet Heads as Determined by Tests of Planing Surfaces

    NASA Technical Reports Server (NTRS)

    Truscott, Starr; Parkinson, J B

    1938-01-01

    The increase in the frictional resistance of a surface caused by the presence of rivet heads was determined by towing four planing surfaces of the same dimensions. One surface was smooth and represented a surface without rivet heads or one with perfectly flush countersunk rivets. The other three surfaces were each fitted with the same number of full-size rivet heads but of a different type arranged in the same pattern on each surface. The surfaces were towed at speeds representative of the high water speeds encountered by seaplanes during take-off and the range of Reynolds Number covered by the test was from 4 x 10(exp 6) to 18 x 10(exp 6). The rivet heads investigated were oval countersunk, brazier, and round for rivets having shanks 5/32 inch in diameter. The oval countersunk heads were sunk below the surface by dimpling the plating around them. The results of the tests showed that, for the rivet heads investigated, the increase in the friction coefficient of the surface is directly proportional to the height of the rivet head. The order of merit in regard to low resistance is flush countersunk, oval countersunk (whether sunk below the surface or not), brazier, and round.

  3. Fractographic analysis of initiation and growth of fatigue cracks at rivet holes

    NASA Astrophysics Data System (ADS)

    Pelloux, R.; Warren, A.; O'Grady, J.

    A series of fatigue tests were performed on riveted panels of clad 2024-T3 without epoxy bonds. Fatigue crack initiation occurred at the apex of the rivet hole chamfers. Transgranular fatigue crack growth by ductile striation formation occurred through the sheet. The fracture features at low, medium and high growth rates were examined with the SEM. Microscopic crack propagation rates as measured by fatigue striation spacings correlate with macroscopic crack growth rates observed. The fatigue crack growth rate is fairly constant over a length of 6 mm (0.25 in.) from the edge of the rivet hole, due to the fact that the stress intensity range is approximately constant in this region. Transition to fast fracture and unstable crack propagation is readily identified due to marked yielding of the cladding material.

  4. Effect of adherend steel strength on static and fatigue strength of adhesive/rivet combined joint

    NASA Astrophysics Data System (ADS)

    Imanaka, Makoto; Haraga, Kosuke; Nishikawa, Tetsuya

    1992-02-01

    Adhesive/rivet combined bonding has attracted special interest recently as a joining technique of high-strength steel because of its high joint efficiency. In this study, the effects of steel strength on the tensile and fatigue strength of adhesive/rivet combined and adhesive joints were investigated. In addition, the stress distributions of these joints were analyzed by finite-element methods, taking into consideration the plastic deformation of adherend steels. With the increase of steel strength, the tensile strength of combined and adhesive joints increased and tensile strength was improved by the combination with the rivet. However, irrespective of the steel strength, the fatigue strength of combined and adhesive joints was constant and the fatigue strength of the combined joint was similar to that of the adhesive joint. These findings could be explained from the difference of stress distribution between static and fatigue load conditions.

  5. The use of rivets for electrical resistance measurement on carbon fibre-reinforced thermoplastics

    NASA Astrophysics Data System (ADS)

    DeBaere, I.; Van Paepegem, W.; Degrieck, J.

    2007-10-01

    The use of fibre-reinforced thermoplastics, for example in the aeronautical industry, is increasing rapidly. Therefore, there is an increasing need for in situ monitoring tools, which preferably have limited influence on the behaviour of the material and which are easy to use. Furthermore, in the aeronautical industry composites are very often attached with rivets. In this study, the possibility of the use of rivets as contact electrodes for electrical resistance measurement is explored. The material used is a carbon fibre-reinforced polyphenylene sulphide. First, the set-up used is discussed. Then, static tensile tests on the laminate are performed. The possible influence of an extensometer on the measurements is examined. Furthermore, failure predictability is assessed. It may be concluded that the proposed set-up with the rivets can be used for electrical resistance measurement, with the ability to predict failure, and that the extensometer has a negative influence on the resistance measurement.

  6. The mechanics and tribology of fretting fatigue with application to riveted lap joints

    NASA Astrophysics Data System (ADS)

    Szolwinski, Matthew Paul

    Fretting is the synergistic combination of wear, corrosion, and fatigue damage mechanisms driven by the partial slip of contacting surfaces. The surface microslip and near-surface contact stresses associated with fretting can lead to severe reduction in service lifetimes of contacting components as diversified as bearings, turbine blades and mechanically-fastened joints, both structural and biological. This tribologically induced degradation has come under close scrutiny by those responsible for maintaining aging fleets of both commercial and military aircraft. Thus a critical need exists for predicting fretting crack nucleation in riveted aluminum. aircraft joints. Fulfilling this need requires characterizing both the near-surface mechanics and intimately-related tribology of fretting. To this end, a well characterized experimental setup has been developed to generate carefully controlled and monitored fretting contacts to investigate the nature of the near-surface conditions. Included in this investigation were in-situ observations of the fretting contact stress field via a non-invasive thermal imaging technique and a characterization of the evolution of friction under partial slip conditions. With specific qualitative and quantitative understanding of these near-surface conditions, a series of fretting fatigue experiments have been conducted to validate a mechanics-based model for predicting fretting fatigue crack nucleation. Finally, efforts have been directed toward extending this understanding of fretting crack nucleation to riveted aircraft structure through modeling of the riveting process and a related experimental program designed to link riveting process parameters and fretting damage in single-lap joint structures. This work focuses specifically on determination of the residual stresses induced during rivet installation and the morphological characterization of fretting fatigue damage in the riveted test specimens manufactured under controlled

  7. Online visual inspection of self-piercing riveting to determine the quality of the mechanical interlock

    NASA Astrophysics Data System (ADS)

    Johnson, P.; Cullen, J. D.; Al-Shamma'a, A. I.; Shaw, A.

    2007-07-01

    Self-piercing riveting (SPR) has become a significant joining technique for the automotive applications of aluminium sheets. Quality control in this locale has progressed at an altogether more leisurely rate than other areas of mechanical joining (e.g. spotweld) and is underdeveloped. Testing the quality mechanical interlock is often achieved by destructive testing, which results in material and time wastage. The solution is online monitoring of the self-piercing riveting process to provide non-destructive testing of the mechanical interlock. Introducing sensors into the process facilitates real time data acquisition, which can be used to determine the quality of the joint.

  8. Effect of Rivet Pitch Upon the Fatique Strength of Single-Row Riveted Joints of 0.025- to 0.025-inch 24S-T Alclad

    DTIC Science & Technology

    1943-07-01

    P) 12 0.5 ? 0.75 6 1.0 4 1.5 fatigue test specimen Half size Material.- Alclad 24ST Joggle both sheets .013" Figurei 4. 2 I» 1-3 CD I...34both sheets joggled .025-.025 24ST Alclad 6 rivets 1 spacing Ultimate load = 393 lh/rivet 400 +3 ay > u <u ft w o ft ä •H a o 300 200...t soo ÄBT430DD-4 i •ivets joggl .lclad Both sheets .025-.025 4 H = + 0.2 ed 24ST 250 200 ^ 10° cycles __ — 2.5 x 105 05~~ 150

  9. 13. DETAIL, U1 JOINT, FROM BELOW AND SOUTH, SHOWING RIVETED ...

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

    13. DETAIL, U1 JOINT, FROM BELOW AND SOUTH, SHOWING RIVETED CONNECTION, AND INTERSECTION OF END POST, VERTICAL, DIAGONAL AND UPPER CHORD MEMBERS AND LATERAL BRACING - Glendale Road Bridge, Spanning Deep Creek Lake on Glendale Road, McHenry, Garrett County, MD

  10. 14. DETAIL, U3 JOINT, FROM BELOW AND SOUTH, SHOWING RIVETED ...

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

    14. DETAIL, U3 JOINT, FROM BELOW AND SOUTH, SHOWING RIVETED CONNECTION, AND INTERSECTION OF TOP CHORD, VERTICAL U3-L3, DIAGONALS, AND LATERAL BRACING INCLUDING DOUBLE ANGLES WITH LACING BARS - Glendale Road Bridge, Spanning Deep Creek Lake on Glendale Road, McHenry, Garrett County, MD

  11. 16. DETAIL, L1 JOINT, FROM BELOW AND SOUTH, SHOWING RIVETED ...

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

    16. DETAIL, L1 JOINT, FROM BELOW AND SOUTH, SHOWING RIVETED CONNECTION, AND CONFIGURATION OF VERTICAL U1-I1, LOWER CHORD AND FLOOR SYSTEM - Glendale Road Bridge, Spanning Deep Creek Lake on Glendale Road, McHenry, Garrett County, MD

  12. Tensile and fatigue behaviour of self-piercing rivets of CFRP to aluminium for automotive application

    NASA Astrophysics Data System (ADS)

    Kang, J.; Rao, H.; Zhang, R.; Avery, K.; Su, X.

    2016-07-01

    In this study, the tensile and fatigue behaviour of self-piercing rivets (SPRs) in carbon fibre reinforced plastic (CFRP) to aluminium 6111 T82 alloys were evaluated. An average maximum lap-shear tensile load capacity of 3858 N was achieved, which is comparable to metal-to-metal SPR lap-shear joints. The CFRP-Al SPRs failed in lap-shear tension due to pull-out of the rivet head from the CFRP upper sheet. The CFRP-Al SPR lap- shear specimens exhibited superior fatigue life compared to previously studied aluminium-to- aluminium SPR lap-shear joints. The SPR lap-shear joints under fatigue loads failed predominantly due to kinked crack growth along the width of the bottom aluminium sheet. The fatigue cracks initiated in the plastically deformed region of the aluminium sheet close to the rivet shank in the rivet-sheet interlock region. Scatter in fatigue life and failure modes was observed in SPR lap-shear specimens tested close to maximum tensile load.

  13. A biomechanical study of bankart lesion fixation - biodegradable ArthroRivet tack vs. suture repair.

    PubMed

    Collins, Kevin J; Mukherjee, Debi P; Ogden, Alan L; Sadasivan, Kalia K; Albright, James A; Pietrzak, William S

    2007-01-01

    Bioabsorbable fixation is commonly used in soft tissue procedures performed in the shoulder. ArthroRivettrade mark tacks (referred to as rivets here), made from a copolymer of 82% poly-L-lactic acid and 18% polyglycolic acid, were developed for the Bankart procedure. Although a previous in vivo study demonstrated favorable comparison of the fixation strength and absorption characteristics of this device with that of polyglyconate bioabsorbable tacks, there have been no published biomechanical studies of this rivet in the shoulder. Fourteen shoulders were harvested from fresh-frozen cadavers of average age 74 years (46-89). Biomechanical testing was performed by measuring the energy, or work, required to anteriorly displace the humeral head 6 mm from the glenoid. Each shoulder was tested intact, vented, and before and after repair of a simulated Bankart lesion at 0, 45, and 90 degrees of abduction with and without maximal external rotation. Overall, the average work required ranged from 54.7 N-mm to 178.27 N-mm. Although the biomechanical performance of the rivet, based on resistance to anterior displacement of the humeral head, was indistinguishable from that of the suture repair, the statistical power of the test was low due to the large variance in the cadaver specimens. The results, in general, correlated well with those of previously published studies, suggesting the suitability of the bioabsorbable rivet for use in Bankart repair.

  14. 7. TYPICAL INTERIOR AND BOTTOM OF EMPTY 14.5FOOTDIAMETER RIVETED STEEL ...

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

    7. TYPICAL INTERIOR AND BOTTOM OF EMPTY 14.5-FOOT-DIAMETER RIVETED STEEL SOAP KETTLE, WITH STEAM COILS; VIEW DOWN FROM KETTLE TOP, FIFTH FLOOR, EAST BAY, THIRD KETTLE FROM SOUTH - Colgate & Company Jersey City Plant, Building No. B-13, 48-50 Grand Street, Jersey City, Hudson County, NJ

  15. Numerical analysis of static performance comparison of friction stir welded versus riveted 2024-T3 aluminum alloy stiffened panels

    NASA Astrophysics Data System (ADS)

    Shao, Qing; He, Yuting; Zhang, Teng; Wu, Liming

    2014-07-01

    Most researches on the static performance of stiffened panel joined by friction stir welding(FSW) mainly focus on the compression stability rather than shear stability. To evaluate the potential of FSW as a replacement for traditional rivet fastening for stiffened panel assembly in aviation application, finite element method(FEM) is applied to compare compression and shear stability performances of FSW stiffened panels with stability performances of riveted stiffened panels. FEMs of 2024-T3 aluminum alloy FSW and riveted stiffened panels are developed and nonlinear static analysis method is applied to obtain buckling pattern, buckling load and load carrying capability of each panel model. The accuracy of each FEM of FSW stiffened panel is evaluated by stability experiment of FSW stiffened panel specimens with identical geometry and boundary condition and the accuracy of each FEM of riveted stiffened panel is evaluated by semi-empirical calculation formulas. It is found that FEMs without considering weld-induced initial imperfections notably overestimate the static strengths of FSW stiffened panels. FEM results show that, buckling patterns of both FSW and riveted compression stiffened panels represent local buckling of plate between stiffeners. The initial buckling waves of FSW stiffened panel emerge uniformly in each plate between stiffeners while those of riveted panel mainly emerge in the mid-plate. Buckling patterns of both FSW and riveted shear stiffened panels represent local buckling of plate close to the loading corner. FEM results indicate that, shear buckling of FSW stiffened panel is less sensitive to the initial imperfections than compression buckling. Load carrying capability of FSW stiffened panel is less sensitive to the initial imperfections than initial buckling. It can be concluded that buckling loads of FSW panels are a bit lower than those of riveted panels whereas carrying capabilities of FSW panels are almost equivalent to those of riveted

  16. Fatigue Behaviors of Self-Piercing Rivets Joining Similar and Dissimilar Sheet Metals

    SciTech Connect

    Sun, Xin; Stephens, Elizabeth V.; Khaleel, Mohammad A.

    2007-01-01

    This paper summarizes the fatigue test results of self-piercing rivet (SPR) joints between similar and dissimilar sheet metals. The influences of material grades, material thickness, piercing direction and the use of structural adhesive on the rivet samples’ fatigue behaviors were investigated. Fatigue test results indicate that SPR joints have superior fatigue strength than resistance spot weld (RSW) joints for the same material combinations. The application of structure adhesive also significantly enhances the fatigue strength of the joint samples; this is particularly true for the lap shear loading configuration. In addition, different piercing directions for SPR joints have a noticeable effect on the static and fatigue strength of the joints. The joint fatigue results presented in this paper can offer design engineers with the durability data for SPR joints with these material combinations. Moreover, it will provide manufacturing engineers with some insights on the effects of different manufacturing parameters on the strength and durability of these joints.

  17. A Practical Engineering Approach to Predicting Fatigue Crack Growth in Riveted Lap Joints

    NASA Technical Reports Server (NTRS)

    Harris, Charles E.; Piascik, Robert S.; Newman, James C., Jr.

    1999-01-01

    An extensive experimental database has been assembled from very detailed teardown examinations of fatigue cracks found in rivet holes of fuselage structural components. Based on this experimental database, a comprehensive analysis methodology was developed to predict the onset of widespread fatigue damage in lap joints of fuselage structure. Several computer codes were developed with specialized capabilities to conduct the various analyses that make up the comprehensive methodology. Over the past several years, the authors have interrogated various aspects of the analysis methods to determine the degree of computational rigor required to produce numerical predictions with acceptable engineering accuracy. This study led to the formulation of a practical engineering approach to predicting fatigue crack growth in riveted lap joints. This paper describes the practical engineering approach and compares predictions with the results from several experimental studies.

  18. A Practical Engineering Approach to Predicting Fatigue Crack Growth in Riveted Lap Joints

    NASA Technical Reports Server (NTRS)

    Harris, C. E.; Piascik, R. S.; Newman, J. C., Jr.

    2000-01-01

    An extensive experimental database has been assembled from very detailed teardown examinations of fatigue cracks found in rivet holes of fuselage structural components. Based on this experimental database, a comprehensive analysis methodology was developed to predict the onset of widespread fatigue damage in lap joints of fuselage structure. Several computer codes were developed with specialized capabilities to conduct the various analyses that make up the comprehensive methodology. Over the past several years, the authors have interrogated various aspects of the analysis methods to determine the degree of computational rigor required to produce numerical predictions with acceptable engineering accuracy. This study led to the formulation of a practical engineering approach to predicting fatigue crack growth in riveted lap joints. This paper describes the practical engineering approach and compares predictions with the results from several experimental studies.

  19. Two-sided friction stir riveting by extrusion: A process for joining dissimilar materials

    SciTech Connect

    Evans, William T.; Cox, Chase D.; Strauss, Alvin M.; Cook, George E.; Gibson, Brian T.

    2016-06-25

    Two-sided friction stir riveting (FSR) by extrusion is an innovative process developed to rapidly, efficiently, and securely join dissimilar materials. This process extends a previously developed one sided friction stir extrusion process to create a strong and robust joint by producing a continuous, rivet-like structure through a preformed hole in one of the materials with a simultaneous, two-sided friction stir spot weld. The two-sided FSR by extrusion process securely joins the dissimilar materials together and effectively locks them in place without the use of any separate materials or fasteners. Lastly, in this paper we demonstrate the process by joining aluminum to steel and illustrate its potential application to automotive and aerospace manufacturing processes.

  20. Two-sided friction stir riveting by extrusion: A process for joining dissimilar materials

    DOE PAGES

    Evans, William T.; Cox, Chase D.; Strauss, Alvin M.; ...

    2016-06-25

    Two-sided friction stir riveting (FSR) by extrusion is an innovative process developed to rapidly, efficiently, and securely join dissimilar materials. This process extends a previously developed one sided friction stir extrusion process to create a strong and robust joint by producing a continuous, rivet-like structure through a preformed hole in one of the materials with a simultaneous, two-sided friction stir spot weld. The two-sided FSR by extrusion process securely joins the dissimilar materials together and effectively locks them in place without the use of any separate materials or fasteners. Lastly, in this paper we demonstrate the process by joining aluminummore » to steel and illustrate its potential application to automotive and aerospace manufacturing processes.« less

  1. Detection of Fatigue Cracks at Rivets with Self-Nulling Probe

    NASA Technical Reports Server (NTRS)

    Wincheski, Buzz; Fulton, Jim; Nath, Shridhar; Namkung, Min

    1994-01-01

    A new eddy current probe developed at NASA Langley Research Center has been used to detect small cracks at rivets in aircraft lap splices [1]. The device has earlier been used to detect isolated fatigue cracks with a minimum detectable flaw size of roughly 1/2 to 1/3 the diameter of the probe [2]. The present work shows that the detectable flaw size for cracks originating at rivets can be greatly improved upon from that of isolated flaws. The use of a rotating probe method combined with spatial filtering has been used to detect 0.18 cm EDM notches, as measured from the rivet shank, with a 1.27 cm diameter probe and to detect flaws buried under the rivet head, down to a length of 0.076 cm, using a 0.32 cm diameter probe. The Self-Nulling Electromagnetic Flaw Detector induces a high density eddy current ring in the sample under test. A ferromagnetic flux focusing lens is incorporated such that in the absence of any inhomogeneities in the material under test only a minimal magnetic field will reach the interior of the probe. A magnetometer (pickup coil) located in the center of the probe therefore registers a null voltage in the absence of material defects. When a fatigue crack or other discontinuity is present in the test article the path of the eddy currents in the material is changed. The magnetic field associated with these eddy currents then enter into the interior of the probe, producing a large output voltage across the pickup coil leads. Further

  2. Exposure to vibration and self-reported health complaints of riveters in the aircraft industry.

    PubMed

    Burdorf, A; Monster, A

    1991-06-01

    Workers using vibrating tools may experience neurological and vascular symptoms in the fingers and hands. The effect of vibration exposure on bone and joint disorders in the hand, arm and shoulder is less clear. In a cross-sectional study, riveters and controls in an aircraft company were investigated for vibration exposure and health complaints. Vibration measurements showed that frequency-weighted acceleration levels for riveting hammers and bucking bars ranged from 5.5 to 12.3 m s -2. The calculated equivalent frequency-weighted acceleration for a period of 4 h was the questionnaire survey 101 riveters reported statistically significant more complaints of pain and stiffness in their hands and arms when compared with 76 controls with no, or little, exposure to vibration. After 10 years of exposure statistically significant age-adjusted odds ratios (P less than 0.05) were found for vibration-induced white finger (VWF) (1.9) and pain or stiffness of the wrist (3.2). Although they were not statistically significant (0.05 less than P less than 0.10) odds ratios appreciably greater than 1 were found for numbness in fingers (1.6) and pain or stiffness in the elbow (1.6) and the shoulder (1.5), and these complaints were strongly associated with duration of exposure to vibration. With logistic regression the probabilities for a riveter of having symptoms of VWF after 10 and 20 years of exposure was estimated to be P = 0.18 and P = 0.29, respectively, which can be compared with the prevalences predicted by the dose-response relationship for VWF in ISO 5349, which are 10 and 30%. The results of this study suggest that exposure to vibration from working with impact power tools can contribute to complaints of pain and stiffness in the hand, arm and shoulder, and especially in the wrist.

  3. 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.

  4. Joining of molybdenum thin films with copper printed circuit board by laser micro-riveting

    NASA Astrophysics Data System (ADS)

    Zimmer, Klaus; Ehrhardt, Martin; Lorenz, Pierre; Stephan, Tino; Ebert, Robby; Braun, Alexander

    2013-07-01

    The joining of micron devices by bonding of thin films is required for the electrical or mechanical connection of thin film components. Current developments of flexible electronics call for advanced micron interconnection technologies. For the joining of thin film devices on flexible polymer substrates a novel technique called "laser microriveting" (LMR) is introduced and demonstrated which enables the bonding of two thin metal layers of different materials for mechanical and electrical connections. In this approach the mechanical and electrical connections are achieved by geometrical interlocking of the thin film materials as a consequence of pulsed laser irradiation. Imaging by SEM and EDX shows clearly that a hollow rivet of copper is formed interlocking the copper layer with the overlaying molybdenum film. The copper hollow rivet formation is the result of highly-dynamic laser-driven processes of melting, evaporation, recoil pressure formation, material transport processes, and resolidification of the molten copper within a single laser pulse. A contact resistance of less than 100 mΩ for one rivet of approximately 20 μm size was measured. This new approach provides a solution for current problems of joining very dissimilar materials.

  5. Computerized evaluation of holographic interferograms for fatigue crack detection in riveted lap joints

    NASA Astrophysics Data System (ADS)

    Zhou, Xiang

    Using an innovative portable holographic inspection and testing system (PHITS) developed at the Australian Defence Force Academy, fatigue cracks in riveted lap joints can be detected by visually inspecting the abnormal fringe changes recorded on holographic interferograms. In this thesis, for automatic crack detection, some modern digital image processing techniques are investigated and applied to holographic interferogram evaluation. Fringe analysis algorithms are developed for identification of the crack-induced fringe changes. Theoretical analysis of PHITS and riveted lap joints and two typical experiments demonstrate that the fatigue cracks in lightly-clamped joints induce two characteristic fringe changes: local fringe discontinuities at the cracking sites; and the global crescent fringe distribution near to the edge of the rivet hole. Both of the fringe features are used for crack detection in this thesis. As a basis of the fringe feature extraction, an algorithm for local fringe orientation calculation is proposed. For high orientation accuracy and computational efficiency, Gaussian gradient filtering and neighboring direction averaging are used to minimize the effects of image background variations and random noise. The neighboring direction averaging is also used to approximate the fringe directions in centerlines of bright and dark fringes. Experimental results indicate that for high orientation accuracy the scales of the Gaussian filter and neighboring direction averaging should be chosen according to the local fringe spacings. The orientation histogram technique is applied to detect the local fringe discontinuity due to the fatigue cracks. The Fourier descriptor technique is used to characterize the global fringe distribution change from a circular to a crescent distribution with the fatigue crack growth. Experiments and computer simulations are conducted to analyze the detectability and reliability of crack detection using the two techniques. Results

  6. Multifrequency Eddy Current Inspection of Corrosion in Clad Aluminum Riveted Lap Joints and Its Effect on Fatigue Life

    SciTech Connect

    Okafor, A. C.; Natarajan, S.

    2007-03-21

    Aging aircraft are prone to corrosion damage and fatigue cracks in riveted lap joints of fuselage skin panels. This can cause catastrophic failure if not detected and repaired. Hence detection of corrosion damage and monitoring its effect on structural integrity are essential. This paper presents multifrequency eddy current (EC) inspection of corrosion damage and machined material loss defect in clad A1 2024-T3 riveted lap joints and its effect on fatigue life. Results of eddy current inspection, corrosion product removal and fatigue testing are presented.

  7. An assessment of lead controls for torch cutting and rivet removal on steel structures.

    PubMed

    Goldberg, M; Clark, N L; Levin, S M; Zuckerman, N; Doucette, J T

    2000-05-01

    The use of engineering and work practice controls to protect workers from lead-containing dusts and fumes generated during rehabilitation of steel structures is mandated by the Occupational Safety and Health Administration (OSHA) Lead in Construction Standard (1993). Because the implementation and assessment of controls can be problematic in the rugged and dynamic construction environment, industrial hygienists should understand the effectiveness and limitations of controls adopted. The present investigation assesses the efficacy of two controls to reduce lead exposure: paint removal prior to oxy-acetylene torch cutting of steel, and encapsulation of rivets prior to their removal. A task-based exposure assessment approach was used to evaluate these tasks at three sites. Exposures at one site without controls were compared to exposures at sites with controls. Comparison of the results via an analysis of variance (0.05 significance level) indicates that, for torch cutting, exposures at the control site were not significantly different from those at an uncontrolled site (p = 0.14). The results for rivet busting show no significant differences in exposures at the control site compared to the uncontrolled site (p = 0.08). Results are also presented from two control sites where work was done in enclosed spaces. Two main difficulties in applying the controls are explored: technical and managerial. Technical problems during torch cutting included the penetration of paint into the steel profile and the configuration of the structures. For rivet busting, working within an enclosure was an important factor. Management problems arose both from a lack of coordination among different contractors, and from a failure to provide day-to-day guidance and assessment of the control. Important components of a program to implement controls are preplanning and coordination of control implementation, frequent testing of control efficacy, and a method for timely intervention to correct

  8. Three-Dimensional Geometric Nonlinear Contact Stress Analysis of Riveted Joints

    NASA Technical Reports Server (NTRS)

    Shivakumar, Kunigal N.; Ramanujapuram, Vivek

    1998-01-01

    The problems associated with fatigue were brought into the forefront of research by the explosive decompression and structural failure of the Aloha Airlines Flight 243 in 1988. The structural failure of this airplane has been attributed to debonding and multiple cracking along the longitudinal lap splice riveted joint in the fuselage. This crash created what may be termed as a minor "Structural Integrity Revolution" in the commercial transport industry. Major steps have been taken by the manufacturers, operators and authorities to improve the structural airworthiness of the aging fleet of airplanes. Notwithstanding, this considerable effort there are still outstanding issues and concerns related to the formulation of Widespread Fatigue Damage which is believed to have been a contributing factor in the probable cause of the Aloha accident. The lesson from this accident was that Multiple-Site Damage (MSD) in "aging" aircraft can lead to extensive aircraft damage. A strong candidate in which MSD is highly probable to occur is the riveted lap joint.

  9. Optimization and Validation of Rotating Current Excitation with GMR Array Sensors for Riveted Structures Inspection

    PubMed Central

    Ye, Chaofeng; Udpa, Lalita; Udpa, Satish

    2016-01-01

    In eddy current non-destructive testing of a multi-layered riveted structure, rotating current excitation, generated by orthogonal coils, is advantageous in providing sensitivity to defects of all orientations. However, when used with linear array sensors, the exciting magnetic flux density (Bx) of the orthogonal coils is not uniform over the sensor region, resulting in an output signal magnitude that depends on the relative location of the defect to the sensor array. In this paper, the rotating excitation coil is optimized to achieve a uniform Bx field in the sensor array area and minimize the probe size. The current density distribution of the coil is optimized using the polynomial approximation method. A non-uniform coil design is derived from the optimized current density distribution. Simulation results, using both an optimized coil and a conventional coil, are generated using the finite element method (FEM) model. The signal magnitude for an optimized coil is seen to be more robust with respect to offset of defects from the coil center. A novel multilayer coil structure, fabricated on a multi-layer printed circuit board, is used to build the optimized coil. A prototype probe with the optimized coil and 32 giant magnetoresistive (GMR) sensors is built and tested on a two-layer riveted aluminum sample. Experimental results show that the optimized probe has better defect detection capability compared with a conventional non-optimized coil. PMID:27649202

  10. Evaluation of the Mechanical Performance of Self-Piercing Rivets in Friction Stir Welded Structures

    SciTech Connect

    Stephens, Elizabeth V.; Grant, Glenn J.; Davies, Richard W.; Wazny, Scott; Kaunitz, Leon; Fulbright, Brian; Waldron, D.

    2005-04-01

    This paper presents the coupon performance data of friction stir welded tailor welded blanks (TWBs) joined to a monolithic aluminum sheet by self-piercing rivets (SPRs). Uniaxial tensile tests were performed to characterize the joint strength and the total energy absorption capability of the TWB/monolithic joint assemblies. Cyclic fatigue tests were also conducted to characterize the fatigue behavior and failure mechanisms of the jointed assemblies. It was found that the static and fatigue strength of the TWB/monolithic assembly was approximately 30 percent less in all loading configurations tested in comparison to a common monolithic sheet SPR assembly. The total energy absorbed by the TWB/monolithic sheet assemblies was also found to be 30 percent less than the monolithic sheet assemblies in cross tension loading. In lap shear loading, the total energy absorbed was comparable.

  11. The role of fretting corrosion and fretting fatigue in aircraft rivet hole cracking

    NASA Astrophysics Data System (ADS)

    Elliott, Charles B., III; Moesser, Mark; Hoeppner, David W.

    1994-09-01

    Personnel in the Quality and Integrity Design Engineering Center (QIDEC) at the University of Utah are working under a two year grant from the FAA to better understand the role of fretting corrosion and fretting fatigue in aircraft rivet hole cracking. The current program follows a one year grant program which was completed in 1993. This paper provides a status report on the results of these grant programs. Recent effort has been focused on developing basic fretting fatigue models which consider variation in the coefficient of friction with time and location within the fretting interface. This is a very important characteristic of the QIDEC model because coefficient of friction varies significantly during the fretting fatigue process. Copies of QIDEC documents discussed in this paper can be obtained by contacting the authors.

  12. The role of fretting corrosion and fretting fatigue in aircraft rivet hole cracking

    NASA Technical Reports Server (NTRS)

    Elliott, Charles B., III; Moesser, Mark; Hoeppner, David W.

    1994-01-01

    Personnel in the Quality and Integrity Design Engineering Center (QIDEC) at the University of Utah are working under a two year grant from the FAA to better understand the role of fretting corrosion and fretting fatigue in aircraft rivet hole cracking. The current program follows a one year grant program which was completed in 1993. This paper provides a status report on the results of these grant programs. Recent effort has been focused on developing basic fretting fatigue models which consider variation in the coefficient of friction with time and location within the fretting interface. This is a very important characteristic of the QIDEC model because coefficient of friction varies significantly during the fretting fatigue process. Copies of QIDEC documents discussed in this paper can be obtained by contacting the authors.

  13. The Characteristics of Fatigue Damage in the Fuselage Riveted Lap Splice Joint

    NASA Technical Reports Server (NTRS)

    Piascik, Robert S.; Willard, Scott A.

    1997-01-01

    An extensive data base has been developed to form the physical basis for new analytical methodology to predict the onset of widespread fatigue damage in the fuselage lap splice joint. The results of detailed destructive examinations have been cataloged to describe the physical nature of MSD in the lap splice joint. ne catalog includes a detailed description, e.g., crack initiation, growth rates, size, location, and fracture morphology, of fatigue damage in the fuselage lap splice joint structure. Detailed examinations were conducted on a lap splice joint panel removed from a full scale fuselage test article after completing a 60,000 cycle pressure test. The panel contained a four bay region that exhibited visible outer skin cracks and regions of crack link-up along the upper rivet row. Destructive examinations revealed undetected fatigue damage in the outer skin, inner skin, and tear strap regions. Outer skin fatigue cracks were found to initiate by fretting damage along the faying surface. The cracks grew along the faying surface to a length equivalent to two to three skin thicknesses before penetrating the outboard surface of the outer skin. Analysis of fracture surface marker bands produced during full scale testing revealed that all upper rivet row fatigue cracks contained in a dim bay region grow at similar rates; this important result suggests that fracture mechanics based methods can be used to predict the growth of outer skin fatigue cracks in lap splice structure. Results are presented showing the affects of MSD and out-of-plane pressure loads on outer skin crack link-up.

  14. Ultrasonic inspection of multiple-rivet-hole lap joint cracks using global analysis with local finite element approach

    NASA Astrophysics Data System (ADS)

    Bhuiyan, Yeasin; Shen, Yanfeng; Giurgiutiu, Victor

    2016-04-01

    Ultrasonic inspection of multiple-rivet-hole lap joint cracks has been introduced using combined analytical and finite element approach (CAFA). Finite element analyses have been performed on local damage area in spite of the whole large structure and transfer function based analytical model is used to analyze the full structure. "Scattered cube" of complex valued wave damage interaction coefficient (WDIC) that involves scattering and mode conversion of Lamb waves around the damage is used as coupling between analytical and FEM simulation. WDIC is captured for multiple angles of incident Lamb mode (S0 and A0) over the frequency domain to analyze the cracks of multiple-rivet-hole lap joint. By analyzing the scattered cube of WDICs over the frequency domain and azimuthal angles the optimum parameters can be determined for each angle of incidence and the most sensitive signals are obtained using WaveformRevealer2D (WFR2D). These sensitive signals confirm the detection of the butterfly cracks in rivet holes through the installment of the transmitting and sensing PWASs in the proper locations and selecting the right frequency of excitation.

  15. Correlation-based imaging technique for fatigue monitoring of riveted lap-joint structure

    NASA Astrophysics Data System (ADS)

    Quaegebeur, N.; Ostiguy, P. C.; Masson, P.

    2014-05-01

    In the present study, a correlation-based imaging technique called Excitelet is assessed to monitor fatigue crack propagation in a riveted aluminum lap-joint, representative of an aircraft component. For this purpose, a micro-machined piezoceramic array is used to generate guided waves into the structure and measure the reflections induced by potential damage. The method uses a propagation model to correlate measured signals with a bank of signals and imaging is performed using a round-robin procedure (full-matrix capture). This allows taking into account the transducer dynamics and finite dimensions, multi-modal and dispersive characteristics of the guided wave propagation and complex interaction between with damage. Experimental validation has been conducted on an aluminum lap-joint instrumented with a compact linear piezoceramic array of 8 circular elements of 3 mm diameter each. The imaging technique is applied to detect crack propagation after fatigue cycling. Imaging results obtained using A0 mode at 300 and 450 kHz are presented for different crack sizes. It is demonstrated that crack detection and localization can be achieved, while the correlation level indicates the level of reflected energy, and thus damage severity. An accuracy below 5 mm on damage location can be achieved, demonstrating the potential of the correlation-based imaging technique for damage monitoring of complex aerospace structures.

  16. Statistical investigation of fatigue crack initiation and growth around chamfered rivet holes in Alclad 2024 T3 as affected by corrosion

    NASA Technical Reports Server (NTRS)

    Fadragas, M. I.; Fine, M. E.; Moran, B.

    1994-01-01

    In panel specimens with rivet holes cracks initiate in the blunted knife edge of the chamfered rivet hole and propagate inward as well as along the hole. The fatigue lifetime to dominant crack information was defined as the number of cycles, N500 micrometer, to formation of a 500 micrometer long crack. Statistical data on N500 micrometer and on crack propagation after N500 micrometer were obtained for a large number of uncorroded specimens and specimens corroded in an ASTM B 117 salt spray. Considerable variation in N500 micrometer and crack propagation behavior was observed from specimen to specimen of the same nominal geometry with chamfered rivet holes increased the probability for both early formation and later formation of a propagating 500 micrometer fatigue crack. The growth of fatigue cracks after 500 micrometer size was little affected by prior salt spray.

  17. Analytical-variational method of analysis about a finite plate with a cracked hole stiffened by a ring with rivet joints

    NASA Astrophysics Data System (ADS)

    Fu, Dong-Shan; Zhang, Xing

    1995-02-01

    -An analytical-variational method is presented for the solution of a finite plate with both an unloaded cracked large hole and loaded uncracked small holes. This method is also used to solve a problem of a ring with loaded uncracked small holes only. On the foundation of the above analysis, a classical force method is used to solve a problem of a finite plate with a cracked hole stiffened by a ring with rivet joints for determination of rivet forces, stress intensity factor in the stiffened finite plate with a cracked hole and the stress concentration factor in the stiffening ring.

  18. Tank Tests to Show the Effect Rivet Heads on the Water Performance of a Seaplane-Float

    NASA Technical Reports Server (NTRS)

    Parkinson, J B

    1938-01-01

    A 1/3.5 full-sized model of a seaplane float constructed from lines supplied by the Bureau of Aeronautics, Navy Department, was tested first with smooth painted bottom surfaces and then with round-head rivets, plate laps, and keel plates fitted to simulate the actual bottom of a metal float. A percentage increase in water resistance caused by the added roughness was found to be from 5 to 20 percent at the hump speed and from 15 to 40 percent at high speeds. The effect of the roughness of the afterbody was found to be negligible except at high trims. The model data were extrapolated to full size by the usual method that assumes the forces to vary according to Froude's law and, in the case of the smooth model, by a method of separation that takes into account the effect of scale on the frictional resistance. It was concluded that the effect of rivet heads on the take-off performance of a relatively high-powered float seaplane is of little consequence, but it may be of greater importance in the case of more moderately powered flying boats.

  19. Tank Tests of the Effect of Rivet Heads, etc., on the Water Performance of a Seaplane Float, Special Report

    NASA Technical Reports Server (NTRS)

    Parkinson, J. B.; Robertson, J. B., Jr.

    1936-01-01

    A 1/3.5 full-size model of the Mark V float of the Bureau of Aeronautics, Navy Department, was tested in the NACA tank both with smooth painted bottom surfaces and with roundhead rivets, plate laps, and keel plates fitted to simulate the actual bottom of a metal float. The augmentation in water resistance due to the added roughness was found to be from 10-12% at the hum speed and from 12-14% at high speeds. The effect of the roughness of the afterbody was found to be negligible except at high trims. The model data were extrapolated to full size by the usual method which assumes the forces to vary according to Froude's law, and in the case of the smooth model by a method of separation that takes into account the effect of scale on the frictional resistance. It was concluded that the effect of rivet heads on the takeoff performance of a relatively high-powered float seaplane is of little consequence but that it may be of greater importance in the case of more moderately powered flying boats.

  20. Revisiting (Some of) the Lasting Impacts of the Liberty Ships via a Metallurgical Analysis of Rivets from the SS "John W. Brown"

    NASA Astrophysics Data System (ADS)

    Harris, M. D.; Grogg, W. J.; Akoma, A.; Hayes, B. J.; Reidy, R. F.; Imhoff, E. F.; Collins, P. C.

    2015-12-01

    During World War II, 2710 Liberty ships were built in the United States across 18 ship yards. The rate of production of these ships was at a scale not previously witnessed, reflecting a strategic marshaling of national assets critical to the war effort. For the metallurgist, metallurgical engineer, or materials scientist, these ships also struck commanding images regarding their catastrophic failures. The study of these failures led to increased understanding of brittle fracture, fracture mechanics, and ductile-to-brittle transition temperatures. The post-mortem studies of Liberty ships highlighted the importance of composition and microstructure in controlling the properties of steel in fracture-critical applications. This study examines a rivet from the SS "John W. Brown", which was assembled in Baltimore, Maryland, and launched in September 1942, The "John W. Brown" was restored between 1988 and 1991. Classical metallurgical analysis of a rivet from the original 1942 vessel is compared with modern rivets used during its restoration. The rivets provide an analogue to the plate material used in these ships. A comparison of these materials is presented along with a discussion of the importance of composition-microstructure-property relationships that concomitantly evolved.

  1. Carbon-riveted Pt catalyst supported on nanocapsule MWCNTs-Al2O3 with ultrahigh stability for high-temperature proton exchange membrane fuel cells

    NASA Astrophysics Data System (ADS)

    Jiang, Zheng-Zhi; Wang, Zhen-Bo; Qu, Wei-Li; Rivera, Harry; Gu, Da-Ming; Yin, Ge-Ping

    2012-11-01

    Pt catalyst supported on nanocapsule MWCNTs-Al2O3 (multi-walled carbon nanotubes, MWCNTs) catalyst has been prepared by microwave-assisted polyol process (MAPP). The results of electrochemical measurements show that the nanocapsule Pt/MWCNTs-Al2O3 catalyst has higher activity due to more uniform dispersion and smaller size of Pt nanoparticles, and higher stability ascribed to the stronger metal-support interaction (SMSI) between Pt nanoparticles and nanocapsule support than in Pt/MWCNTs. Furthermore, the carbon-riveted nanocapsule Pt/MWCNTs-Al2O3 catalyst has been designed and synthesized on the basis of in situ carbonization of glucose. The physical characteristics such as X-ray diffraction (XRD), energy dispersive analysis of X-ray (EDAX), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) have indicated that α-Al2O3 indeed entered into the inside of the MWCNTs and formed a nanocapsule support of MWCNTs with α-Al2O3 as stuffing. The accelerated potential cycling tests (APCT) show that carbon-riveted nanocapsule Pt/MWCNTs-Al2O3 possesses 10 times the stability of Pt/C and has 4.5 times the life-span of carbon-riveted Pt/TiO2-C reported in our previous work. The significantly enhanced stability for carbon-riveted nanocapsule Pt/MWCNTs-Al2O3 catalyst is attributed to the reasons as follows: the inherently excellent mechanical resistance and stability of α-Al2O3 and MWCNTs in acidic and oxidative environments; SMSI between Pt nanoparticles and the nanocapsule support; the anchoring effect of the carbon layers formed during the carbon-riveting process (CRP); the increase of Pt(0) composition during CRP.

  2. Analytical developments in support of the NASA aging aircraft program with an application to crack growth from rivets

    NASA Astrophysics Data System (ADS)

    Swenson, Daniel; Gondhalekar, Sudhir; Dawicke, Dave

    The NASA Airframe Structural Integrity Program is a multi-disciplinary program to develop analysis methodology, a fracture data base, and improved methods of nondestructive evaluation (NDE) detection of disbonds and cracks. As part of this program, analysis tools to predict crack growth rates and fracture propagation in shell structures are being developed. This paper describes a finite element model of crack growth in layered structures, such as lap splice joints. The model is developed using separate two-dimensional meshes of individual layers which can overlap in space. These layers can be connected with either rivit elements or by adhesive elements. Cracks can be modeled in any layer, with automatic remeshing during crack growth. Using the model, an investigation was made of the effect of rivet interference on fatigue crack growth from a loaded rivit hole. It was found that the interference reduced the stress intensity factor range significantly, resulting in slower crack growth.

  3. A record of all marker bands found in the upper rivet rows of 2 adjacent bays from a fuselage lap splice joint

    NASA Technical Reports Server (NTRS)

    Willard, Scott A.

    1995-01-01

    A full scale fuselage test article was subjected to 60,000 load cycles (pressurizations) to study the effect of widespread fatigue damage in fuselage structures. Every 10,000 cycles coded marker block loading sequences were used to mark the fracture surfaces of the fatigue cracks propagating within the panel. The loading sequences consisted of series of underloads combined with a series of full pressurizations. The combination of loads and underloads marked the fracture surfaces with marker bands that could later be used to reconstruct the fatigue crack growth history of selected regions within the test article. Thirty rivet holes comprising the upper rivet rows from two adjacent bays (bays #3 and #4) from a fuselage lap splice joint were examined for the purpose of this study. Optical and scanning electron microscopy (SEM) were used to locate the marker bands.

  4. Compression Buckling Behavior of Large-Scale Friction Stir Welded and Riveted 2090-T83 Al-Li Alloy Skin-Stiffener Panels

    NASA Technical Reports Server (NTRS)

    Hoffman, Eric K.; Hafley, Robert A.; Wagner, John A.; Jegley, Dawn C.; Pecquet, Robert W.; Blum, Celia M.; Arbegast, William J.

    2002-01-01

    To evaluate the potential of friction stir welding (FSW) as a replacement for traditional rivet fastening for launch vehicle dry bay construction, a large-scale friction stir welded 2090-T83 aluminum-lithium (Al-Li) alloy skin-stiffener panel was designed and fabricated by Lockheed-Martin Space Systems Company - Michoud Operations (LMSS) as part of NASA Space Act Agreement (SAA) 446. The friction stir welded panel and a conventional riveted panel were tested to failure in compression at the NASA Langley Research Center (LaRC). The present paper describes the compression test results, stress analysis, and associated failure behavior of these panels. The test results provide useful data to support future optimization of FSW processes and structural design configurations for launch vehicle dry bay structures.

  5. Dynamic Strength Evaluations for Self-Piercing Rivets and Resistance Spot Welds Joining Similar and Dissimilar Metals

    SciTech Connect

    Sun, Xin; Khaleel, Mohammad A.

    2007-10-01

    This paper summarizes the dynamic joint strength evaluation procedures and the measured dynamic strength data for thirteen joint populations of self-piercing rivets (SPR) and resistance spot welds (RSW) joining similar and dissimilar metals. A state-of-the-art review of the current practice for conducting dynamic tensile/compressive strength tests in different strain rate regimes is first presented, and the generic issues associated with dynamic strength test are addressed. Then, the joint strength testing procedures and fixture designs used in the current study are described, and the typical load versus displacement curves under different loading configurations are presented. Uniqueness of the current data compared with data in the open literature is discussed. The experimental results for all the joint populations indicate that joint strength increases with increasing loading rate. However, the strength increase from 4.47m/s (10mph) to 8.94m/s (20mph) is not as significant as the strength increase from static to 4.47m/s. It is also found that with increasing loading velocity, displacement to failure decreases for all the joint samples. Therefore, “brittleness” of the joint sample increases with impact velocity. Detailed static and dynamic strength data and the associated energy absorption levels for all the samples in the thirteen joint populations are also included.

  6. Initiation and growth of multiple-site damage in the riveted lap joint of a curved stiffened fuselage panel: An experimental and analytical study

    NASA Astrophysics Data System (ADS)

    Ahmed, Abubaker Ali

    As part of the structural integrity research of the National Aging Aircraft Research Program, a comprehensive study on multiple-site damage (MSD) initiation and growth in a pristine lap-joint fuselage panel has been conducted. The curved stiffened fuselage panel was tested at the Full-Scale Aircraft Structural Test Evaluation and Research (FASTER) facility located at the Federal Aviation Administration William J. Hughes Technical Center. A strain survey test was conducted to verify proper load application. The panel was then subjected to a fatigue test with constant-amplitude cyclic loading. The applied loading spectrum included underload marker cycles so that crack growth history could be reconstructed from post-test fractographic examinations. Crack formation and growth were monitored via nondestructive and high-magnification visual inspections. Strain gage measurements recorded during the strain survey tests indicated that the inner surface of the skin along the upper rivet row of the lap joint experienced high tensile stresses due to local bending. During the fatigue loading, cracks were detected by eddy-current inspections at multiple rivet holes along the upper rivet row. Through-thickness cracks were detected visually after about 80% of the fatigue life. Once MSD cracks from two adjacent rivet holes linked up, there was a quick deterioration in the structural integrity of the lap joint. The linkup resulted in a 2.87" (72.9-mm) lead fatigue crack that rapidly propagated across 12 rivet holes and crossed over into the next skin bay, at which stage the fatigue test was terminated. A post-fatigue residual strength test was then conducted by loading the panel quasi-statically up to final failure. The panel failed catastrophically when the crack extended instantaneously across three additional bays. Post-test fractographic examinations of the fracture surfaces in the lap joint of the fuselage panel were conducted to characterize subsurface crack initiation and

  7. Asbestos fibres in the lungs of an American mechanic who drilled, riveted, and ground brake linings: a case report and discussion.

    PubMed

    Finkelstein, Murray M

    2015-05-01

    In North America and Europe, the use of asbestos in friction products was discontinued before the end of the 20th century. In the developing world, the use of asbestos-containing friction products continues. In 2010, Cely-Garcia and colleagues (Cely-Garcia et al., 2012) sampled three brake repair shops located in Bogota, Colombia. Both asbestos and non-asbestos containing brake linings were sold separately or attached to a shoe. When brake linings are sold separated from the shoe, they must be manipulated to attach them to the shoe before installation. The process starts with the removal of the old brake shoe from the vehicle's brake drum. If the existing brake shoe is to be reused, the old lining needs to be removed and the old shoe must be ground to prepare it for a new lining. Riveting requires drilling holes in the linings and shoes and before installing rivets, the lining must be countersunk. The borders of the lining are bevelled. On some occasions, the entire exposed surface of the lining is ground to make it thinner. Once attached to the shoe, the edges of brake linings may extend beyond the shoe. In this case, it is necessary to cut or grind the edges to match the lining to the shoe before bevelling or grinding. The authors reported that 'the sampling results indicate that the brake mechanics sampled are exposed to extremely high asbestos concentrations (i.e. based on transmission electron microscopy counts), suggesting that this occupational group could be at excess risk of asbestos-related diseases'.

  8. A multi-feature integration method for fatigue crack detection and crack length estimation in riveted lap joints using Lamb waves

    NASA Astrophysics Data System (ADS)

    He, Jingjing; Guan, Xuefei; Peng, Tishun; Liu, Yongming; Saxena, Abhinav; Celaya, Jose; Goebel, Kai

    2013-10-01

    This paper presents an experimental study of damage detection and quantification in riveted lap joints. Embedded lead zirconate titanate piezoelectric (PZT) ceramic wafer-type sensors are employed to perform in situ non-destructive evaluation (NDE) during fatigue cyclical loading. PZT wafers are used to monitor the wave reflection from the boundaries of the fatigue crack at the edge of bolt joints. The group velocity of the guided wave is calculated to select a proper time window in which the received signal contains the damage information. It is found that the fatigue crack lengths are correlated with three main features of the signal, i.e., correlation coefficient, amplitude change, and phase change. It was also observed that a single feature cannot be used to quantify the damage among different specimens since a considerable variability was observed in the response from different specimens. A multi-feature integration method based on a second-order multivariate regression analysis is proposed for the prediction of fatigue crack lengths using sensor measurements. The model parameters are obtained using training datasets from five specimens. The effectiveness of the proposed methodology is demonstrated using several lap joint specimens from different manufactures and under different loading conditions.

  9. Fatigue Strength and Related Characteristics of Aircraft Joints I : Comparison of Spot-Weld and Rivet Patterns in 24s-t Alclad and 75s-t Alclad

    NASA Technical Reports Server (NTRS)

    Russell, H W; Jackson, L R; Grover, H J; Beaver, W W

    1944-01-01

    Report contains detailed results of a number of fatigue tests on spot-welded joints in aluminum alloys. The tests described include: (1) fatigue tests on spot-welded lap joints in sheets of unequal thickness of alclad 24s-t. These tests indicate that the fatigue strength of a spot-welded joint in sheets of two different gages is slightly higher than that of a similar joint in two sheets of the thinner gage but definitely lower than that of a similar joint in two sheets of the thicker gage. (2) Fatigue tests on spot-welded alclad 75s-t spot-welded lap-joint specimens of alclad 75s-t were not any stronger in fatigue than similar specimens of alclad 24s-t. (3) Fatigue tests on lap-joint specimens spot -welded after various surface preparations--these included ac welding wire-brushed surfaces, dc welding wire-brushed surfaces, and dc welding chemically cleaned surfaces. While the ac welds were strongest statically, the dc welds on wire-brushed surfaces were strongest in fatigue. Specimens prepared in this way were very nearly as strong as the best riveted specimens tested for comparison. (4) Fatigue tests on specimens spot-welded with varying voltage so as to include a wide range of static spot-weld strengths. The fatigue strengths were in the same order as the static strengths but showed less range. (author)

  10. Tests on riveted joints in sheet duralumin

    NASA Technical Reports Server (NTRS)

    Rettew, H F; Thumin, G

    1923-01-01

    In making tension tests, the slippage of the joints was noted at three points across each joint. In addition, stress strain curves were obtained for plain tension specimens, and a chemical analysis was made of the sheet.

  11. Whatever Happened to Rosie the Riveter?

    ERIC Educational Resources Information Center

    Nichols, Nancy A.

    1993-01-01

    Being judged both as women and managers, women managers risk being perceived as ineffective managers or "unwomanly" women. The key to changing perceptions of women in organizations is a critical mass of women at senior levels, redefining management along less gender-specific lines. (SK)

  12. 46 CFR 109.573 - Riveting, welding, and burning operations.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... chemist certified by the National Fire Protection Association; or (B) If a certified marine chemist is not... by— (A) A marine chemist certified by the National Fire Protection Association; (B) If a certified marine chemist is not available, a person designated by the Officer in Charge, Marine Inspection; or...

  13. 46 CFR 109.573 - Riveting, welding, and burning operations.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... chemist certified by the National Fire Protection Association; or (B) If a certified marine chemist is not... by— (A) A marine chemist certified by the National Fire Protection Association; (B) If a certified marine chemist is not available, a person designated by the Officer in Charge, Marine Inspection; or...

  14. 46 CFR 109.573 - Riveting, welding, and burning operations.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... chemist certified by the National Fire Protection Association; or (B) If a certified marine chemist is not... by— (A) A marine chemist certified by the National Fire Protection Association; (B) If a certified marine chemist is not available, a person designated by the Officer in Charge, Marine Inspection; or...

  15. 46 CFR 109.573 - Riveting, welding, and burning operations.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... chemist certified by the National Fire Protection Association; or (B) If a certified marine chemist is not... by— (A) A marine chemist certified by the National Fire Protection Association; (B) If a certified marine chemist is not available, a person designated by the Officer in Charge, Marine Inspection; or...

  16. The New Workforce: Not Just Rosie the Riveter.

    ERIC Educational Resources Information Center

    Sullivan, Leila Gonzalez

    American women have always been an integral part of the work force, first on the family farm and later as industrial laborers. In World War II, millions of women went to work only to be sent back home when the men returned. Today, women are in a very different situation. Between 1985 and 2000, 80% of new entrants into the work force are expected…

  17. Close Encounters with Deadly Dangers: Riveting Reads and Classroom Ideas.

    ERIC Educational Resources Information Center

    Haven, Kendall

    This book presents 15 tales that bring the animal world into the classroom. The stories in this book are divided into two sections: stories from aquatic ecosystems (both fresh- and saltwater systems), and from terrestrial systems, including desert, meadow, woodland, mountain, Arctic tundra, savanna, pine forest, and jungle ecosystems. All predator…

  18. Mission Crew Fatigue during RIVET JOINT Block II Demonstration/Evaluation.

    DTIC Science & Technology

    1980-11-01

    you feel RIGHT NOW. STATEMENT SETTER THAN SAME AS WORSE THAN 1. VERY LIVELY 2. EXTREMELY TIRED & QUITE FRESH & SLIGHTLY POOPED 0 S, EXTREMELY PEPPV 6...SOMEWHAT PRISMJ 7. PETERED OUT •Z L. VERY REFRESHED 9. FAIL.Y WELL POOPED Re IEADY TO DROP WE SAM roy’" 136 SUBJECTIVE FATIGUE CNECKCARDGaip 74 aa

  19. Multiplexed HTS rf SQUID magnetometer array for eddy current testing of aircraft rivet joints

    NASA Astrophysics Data System (ADS)

    Gärtner, S.; Krause, H.-J.; Wolters, N.; Lomparski, D.; Wolf, W.; Schubert, J.; Kreutzbruck, M. v.; Allweins, K.

    2002-05-01

    Using three rf SQUID magnetometers, a multiplexed SQUID array was implemented. The SQUIDs are positioned in line with 7 mm spacing and operated using one feedback electronics with sequential read out demodulation at different radio frequencies (rf). The cross-talk between SQUID channels was determined to be negligible. To show the performance of the SQUID array, eddy current (EC) measurements of aluminum aircraft samples in conjunction with a differential (double-D) EC excitation and lock-in readout were carried out. With computer-controlled continuous switching of the SQUIDs during the scan, three EC signal traces of the sample are obtained simultaneously. We performed measurements with an EC excitation frequency of 135 Hz to localize an artificial crack (sawcut flaw) of 20 mm length in an aluminum sheet with 0.6 mm thickness. The flaw was still detected when covered with aluminum of up to 10 mm thickness. In addition, measurements with varying angles between scanning direction and flaw orientation are presented.

  20. RIVETS: A Mechanical System for In Vivo and In Vitro Electrophysiology and Imaging

    PubMed Central

    Osborne, Jason E.; Dudman, Joshua T.

    2014-01-01

    A number of recent studies have provided compelling demonstrations that both mice and rats can be trained to perform a variety of behavioral tasks while restrained by mechanical elements mounted to the skull. The independent development of this technique by a number of laboratories has led to diverse solutions. We found that these solutions often used expensive materials and impeded future development and modification in the absence of engineering support. In order to address these issues, here we report on the development of a flexible single hardware design for electrophysiology and imaging both in brain tissue in vitro. Our hardware facilitates the rapid conversion of a single preparation between physiology and imaging system and the conversion of a given system between preparations. In addition, our use of rapid prototyping machines (“3D printers”) allows for the deployment of new designs within a day. Here, we present specifications for design and manufacturing as well as some data from our lab demonstrating the suitability of the design for physiology in behaving animals and imaging in vitro and in vivo. PMID:24551206

  1. An Absolutely Riveting Online Course: Nine Principles for Excellence in Web-Based Teaching

    ERIC Educational Resources Information Center

    Henry, Jim; Meadows, Jeff

    2008-01-01

    This article explores excellence in web-­based teaching. Drawing on the views of experts in the field and the perspective of their own years of experience, the authors compiled a list of 9 principles to provide direction in the search for online excellence. The principles include: the online world is a medium unto itself; sense of community and…

  2. Aircraft Assembly, Riveting and Surface Repair 2; Sheet Metal Work 2: 9855.03.

    ERIC Educational Resources Information Center

    Dade County Public Schools, Miami, FL.

    This course provides experience in assembly techniques, including repairs on aircraft structures, utilizing all methods from basic layout to surface protection of finished parts. Course content includes goals, specific objectives, metal fasteners, general structural repairs, and aircraft assembly. A bibliography and post-test are appended. Prior…

  3. Teaching about Rosie the Riveter: The Role of Women during World War II.

    ERIC Educational Resources Information Center

    Anderson, Karen

    1988-01-01

    Discusses a neglected area of U.S. history: the impact of World War II on the role and status of women. Shows how women's work in the home and in the community assisted the national defense effort, and examined the way that changes in employment opportunities affected traditional ideas about women's roles and fostered the modern women's movement.…

  4. Aircraft Assembly, Riveting and Surface Repair 1; Sheet Metal Work 2: 9855.02.

    ERIC Educational Resources Information Center

    Dade County Public Schools, Miami, FL.

    The course outline will serve as a guide to the 11th grade student interested in sheet metal occupations. The course, 135 hours in length, covers the basic techniques of cutting and trimming, drilling and hole preparation of metals. Lecture and demonstration techniques are to be utilized, with emphasis on the use of visual aids, mock-ups,…

  5. 78 FR 41886 - Airworthiness Directives; Bell Helicopter Textron Canada Limited Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-12

    ... proposed actions are intended to detect a crack, loose rivet, corrosion, or any other damage, which could... inspection of the fitting for a crack, loose rivets, corrosion, and damage at each 100-hour or annual... is a loose rivet, the ASB specifies replacing the rivet with an airworthy rivet. If the fitting...

  6. 46 CFR 126.160 - Tests and inspections during repairs or alterations, or during riveting, welding, burning, or...

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... chemist certified by the NFPA must make the examination. If the services of such a chemist are not..., where the services of a certified marine chemist or other person authorized by the cognizant OCMI...

  7. 46 CFR 126.160 - Tests and inspections during repairs or alterations, or during riveting, welding, burning, or...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... chemist certified by the NFPA must make the examination. If the services of such a chemist are not..., where the services of a certified marine chemist or other person authorized by the cognizant OCMI...

  8. 46 CFR 126.160 - Tests and inspections during repairs or alterations, or during riveting, welding, burning, or...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... chemist certified by the NFPA must make the examination. If the services of such a chemist are not..., where the services of a certified marine chemist or other person authorized by the cognizant OCMI...

  9. 46 CFR 126.160 - Tests and inspections during repairs or alterations, or during riveting, welding, burning, or...

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... chemist certified by the NFPA must make the examination. If the services of such a chemist are not..., where the services of a certified marine chemist or other person authorized by the cognizant OCMI...

  10. Vulnerabilities of the Global Positioning System and the Impact on the Iron Triad: The AWACS, JSTARS, and Rivet Joint Fleets

    DTIC Science & Technology

    2010-06-11

    bodies is not new. As early as the 1700s, mariners were navigating with octants, and later sextants , to fix their positions off the sun, moon, and...trained in celestial navigation and the use of a sextant as the USAF transitioned to heavier reliance on GPS as a primary source for aircraft navigation

  11. A Guide for Developing Human-Robot Interaction Experiments in the Robotic Interactive Visualization and Experimentation Technology (RIVET) Simulation

    DTIC Science & Technology

    2016-05-01

    camera views: example of a birds -eye view ........................69 Fig. C-5 How to save a new mission file...the importance of clearly identifying what they call the “task-oriented” requirements, instead of the “task-specific” requirements. This publication...release; distribution is unlimited. 13 Eastern town versus US military post), terrain and weather specifications, potential risks, stationary and

  12. Dynamics of Sandwaves under Combined Wave - Current Forcing and Mine Burial Processes, and RIVET I and Mine Burial Analysis

    DTIC Science & Technology

    2013-09-30

    the mine burial project has been documented in previous annual reports. Preparation of new side-looking multibeam bedform imaging sonars and mine...Instrumentation for Plume, Sediment and Bed Dynamics in Energetic Coastal Environments: A Multibeam Sidescan Sonar and Portable Turbulance Profiler”) is a...support of optical measurements of particle dynamics (Environmental Optics ), and integrating the pcADPs on Geyer’s MAST (Physical Oceanography). The

  13. 78 FR 25361 - Airworthiness Directives; Eurocopter Deutschland GmbH Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-01

    ... AD requires inspecting the long tail rotor drive shaft assembly for blind rivets, and if any blind... helicopters have blind rivets installed in the place of solid rivets in the long tail rotor drive shaft. The actions of this AD are intended to detect blind rivets installed in the long tail rotor drive shaft,...

  14. Anderson, S.C., Woman Gets Prison for Extensive Bank Fraud Scam and Environmental Crime Nancy Stein operated American Screw and Rivet Corporation which was also sentenced

    EPA Pesticide Factsheets

    ATLANTA - United States Attorney Bill Nettles stated late yesterday that Nancy Marie Stein, age 62, of Anderson, South Carolina , was sentenced by Senior United States District Judge Henry M. Herlong in federal court in Greenville, to a total of 73

  15. VIEW EAST SHOWING THE WEST SIDE OF THE FORWARD (BOW) ...

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

    VIEW EAST SHOWING THE WEST SIDE OF THE FORWARD (BOW) SECTION - Rosie the Riveter National Historical Park, Rosie the Riveter Memorial, Off Regatta at Melville Square in Marina Park, Richmond, Contra Costa County, CA

  16. VIEW SOUTH FROM WITHING THE FORWARD (BOW) SECTION Rosie ...

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

    VIEW SOUTH FROM WITHING THE FORWARD (BOW) SECTION - Rosie the Riveter National Historical Park, Rosie the Riveter Memorial, Off Regatta at Melville Square in Marina Park, Richmond, Contra Costa County, CA

  17. VIEW SOUTH SHOWING THE STRUCTURE REPRESENTING THE FORWARD (BOW) SECTION ...

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

    VIEW SOUTH SHOWING THE STRUCTURE REPRESENTING THE FORWARD (BOW) SECTION OF A LIBERTY SHIP - Rosie the Riveter National Historical Park, Rosie the Riveter Memorial, Off Regatta at Melville Square in Marina Park, Richmond, Contra Costa County, CA

  18. Classification of Magneto-Optic Images using Neural Networks

    NASA Technical Reports Server (NTRS)

    Nath, Shridhar; Wincheski, Buzz; Fulton, Jim; Namkung, Min

    1994-01-01

    A real time imaging system with a neural network classifier has been incorporated on a Macintosh computer in conjunction with an MOI system. This system images rivets on aircraft aluminium structures using eddy currents and magnetic imaging. Moment invariant functions from the image of a rivet is used to train a multilayer perceptron neural network to classify the rivets as good or bad (rivets with cracks).

  19. 78 FR 12991 - Airworthiness Directives; The Boeing Company Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-26

    ... Company Model 767 airplanes. One AD currently requires a functional check of the shear rivets in all six elevator power control actuator (PCA) bellcrank assemblies to determine the condition of the shear rivets... to prevent continued operation with yielded or failed shear rivets in the elevator PCA...

  20. 75 FR 63058 - Airworthiness Directives; PIAGGIO AERO INDUSTRIES S.p.A Model PIAGGIO P-180 Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-14

    ... a manufacturing error, some rivets, required by drawings, were not installed in the joints between... (TIS) after November 18, 2010 (the effective date of this AD), replace the rivets of the joint brackets... product. The MCAI describes the unsafe condition as: Due to a manufacturing error, some rivets,...

  1. 76 FR 63177 - Airworthiness Directives; Airbus Model A300 B2-1C, A300 B2-203, A300 B2K-3C, A300-B4-103, A300 B4...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-12

    ...]racks * * * in sections 13 to 18 of the fuselage between rivets of longitudinal lap joints between... to 18 of the fuselage between rivets of longitudinal lap joints between frames 18 and 80 which could... in order to prevent cracks development in sections 13 to 18 of the fuselage between rivets...

  2. 78 FR 78699 - Airworthiness Directives; Bell Helicopter Textron Canada Limited Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-27

    ... crack, loose rivet, corrosion, or any other damage, which could lead to loss of the tailboom and... loose rivet. If there is a crack or corrosion or damage beyond acceptable limits, the NPRM proposed to... acceptable limits, the NPRM proposed to require repairing the fitting. If there is a loose rivet, the...

  3. 76 FR 26962 - Airworthiness Directives; Airbus Model A300 B2-1C, A300 B2-203, A300 B2K-3C, A300-B4-103, A300 B4...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-10

    ... fuselage between rivets of longitudinal lap joints between frames 18 and 80 which could affect the... fuselage between rivets of longitudinal lap joints between frames 18 and 80 which could affect the... prevent cracks development in sections 13 to 18 of the fuselage between rivets of longitudinal lap...

  4. 46 CFR 35.01-1 - Inspection and testing required when making alterations, repairs, or other such operations...

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ..., repairs, or other such operations involving riveting, welding, burning, or like fire-producing actions-TB..., repairs, or other such operations involving riveting, welding, burning, or like fire-producing actions—TB... safety, no alterations, repairs, or other such operations involving riveting, welding, burning, or...

  5. 46 CFR 71.60-1 - Inspection and testing required when making alterations, repairs, or other such operations...

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ..., repairs, or other such operations involving riveting, welding, burning or like fire-producing actions. 71... required when making alterations, repairs, or other such operations involving riveting, welding, burning or... undertaken with safety, no alterations, repairs, or other such operations involving riveting,...

  6. 76 FR 55785 - Airworthiness Directives; Bombardier, Inc. Model DHC-8-400 Series Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-09

    .... Investigations revealed that loose rivets in the torque tube assemblies caused relative motion between the crank arms and torque tubes. Loose rivets could result in excessive wear and subsequent significant backlash... engaged. Investigations revealed that loose rivets in the torque tube assemblies caused relative...

  7. High-strength combination fasteners for joint assembly in aircraft structures

    NASA Astrophysics Data System (ADS)

    Vasil'Ev, S. L.; Gromov, V. F.; Liapunov, M. L.; Maslov, Iu. V.

    Two new titanium alloy rivet designs intended for the assembly of the aluminum structures of wide-body aircraft are described. One type of rivet consists of a bushing of VT16 titanium alloy and a pin of V65 alloy. The other rivet is a three-element design consisting of a pin with two end cavities filled with inserts of V65 alloy. The new rivets make it possible to produce high-strength joints using automatic equipment and can be used instead of bolt-rivets of titanium alloys.

  8. Summary of Results of Tests Made by Aluminum Research Laboratories of Spot-welded Joints and Structural Elements

    NASA Technical Reports Server (NTRS)

    HARTMANN E C; Stickley, G W

    1942-01-01

    Available information concerning spot welding as a means of joining aluminum-alloy parts has been summarized and comparisons have been made of the relative merits of spot-welded and riveted aluminum-alloy structural elements. The results indicated that spot welding was as satisfactory as riveting insofar as resistance to static loads is concerned. Spot welds showed slightly lower resistance to impact loads but definitely lower resistance to repeated loads than rivets.

  9. Demonstration of Ice-Free Cathodic Protection Systems for Water Storage Tanks at Fort Drum: Final Report on Project AR-F-318 for FY05

    DTIC Science & Technology

    2007-06-01

    and immovable with fingers. Body side rivet base and outside rivet burr should be flat against the material. Bent rivets will fail under stress ...such as using knots, tying around sharp edges, etc.) and maximum permitted free fall distance. Also, to be stressed are the importance of inspections...limitations; e. Application limits; f. Proper hook -up, anchoring and tie-off techniques, including the proper dee-ring or other attachment point to use on

  10. Recapitalization and Acquisition of Light Tactical Wheeled Vehicles (REDACTED)

    DTIC Science & Technology

    2010-01-29

    has welded joints , which are superior to the riveted joints on the M1151. The welded joints help prevent the vehicle from collapsing during an...The XM1166 crew compartment structure, which features welded joints instead of the riveted joints of the M1151, helps prevent the vehicle from...a crew compartment structure that features welded joints instead of the riveted joints of the M1151 and helps prevent the vehicle from collapsing

  11. Knowledge, Models and Tools in Support of Advanced Distance Learning

    DTIC Science & Technology

    2006-06-01

    authoring iRides simulations and training, Rivets , is a fast C++ program that has been compiled for three Unix-type operating systems: Linux, Silicon...School instructors to introduce core concepts of the tool in advance of teaching about expected value theory. 4.0 Rivets -Linux-based Authoring of...Simulations and Instruction Functioning versions of Rivets , a descendent of the classic RIDES program have been developed for Linux and for the Macintosh

  12. A modified self-calibrating technique for an ultrasonic bridge

    NASA Astrophysics Data System (ADS)

    Komsky, I. N.; Achenbach, J. D.

    A second-generation ultrasonic bridge is presented for dry-contact self-calibrated measurements of wave velocities and amplitude changes over the gauge length of the ultrasonic bridge. The modified bridge and the modified self-calibrating technique are applied to the detection of radial edge cracks emanating from a countersunk rivet in a rivet joint of two aluminum plates. The transmission of ultrasound across the rivet joint for a sequence of placements of the bridge at increasing distances from the center of the rivet for ultrasound propagation parallel and normal to the crack direction is investigated. Waveforms for the propagation of ultrasound normal and parallel to the crack are shown.

  13. Welded Permanent Fittings for Titanium Hydraulic Tubing.

    DTIC Science & Technology

    FITTINGS, *HYDRAULIC EQUIPMENT, RIVETED JOINTS, TITANIUM ALLOYS, PIPES , JET TRANSPORT AIRCRAFT, COLD WORKING, PRESSURE, RUPTURE, ARC WELDING , INERT...GAS WELDING , RADIOGRAPHY, STRESS RELIEVING, SUPERSONIC AIRCRAFT, COMMERCIAL AIRCRAFT.

  14. 77 FR 10406 - Airworthiness Directives; The Boeing Company Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-22

    ... deactivation pin. This proposed AD would add a dye penetrant inspection for cracking of the rivet holes of the... a dye penetrant inspection for cracking of the rivet holes of the bushing plate; repair or... Alert Service Bulletin 767-78A0089, Revision 5, dated June 9, 2009, do a dye penetrant inspection...

  15. 77 FR 41895 - Airworthiness Directives; The Boeing Company Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-17

    ... requires a dye penetrant inspection for cracking of the rivet holes of the bushing plate and repair or..., improved components. That NPRM also proposed to require a dye penetrant inspection for cracking of the..., dated June 9, 2009, do a dye penetrant inspection for cracking of the rivet holes and replace any...

  16. 49 CFR 179.201-3 - Lined tanks.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... lining, at least 5/32-inch thick, except overall rivets and seams formed by riveted attachments in the lining must be double thickness. The rubber lining must overlap at least 11/2 inches at all edges which must be straight and be beveled to an angle of approximately 45°, or butted edges of lining must...

  17. 46 CFR 160.043-4 - Construction and workmanship.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... of the blade shall be polished. (d) Linings and center. Linings and center shall be not less than 0... and fastened to the linings by two solid rivets countersunk on the inside of the linings and smoothly rounded on the outside. (h) Rivets and pins. Pins holding the handles to the linings shall be of...

  18. VIEW NORTH FROM THE AFT (FANTAIL) SECTION OF THE MEMORIAL, ...

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

    VIEW NORTH FROM THE AFT (FANTAIL) SECTION OF THE MEMORIAL, LOOKING FORWARD TOWARD THE STACK AND BOW SECTIONS - Rosie the Riveter National Historical Park, Rosie the Riveter Memorial, Off Regatta at Melville Square in Marina Park, Richmond, Contra Costa County, CA

  19. 78 FR 18226 - Airworthiness Directives; Hughes Helicopters, Inc., and McDonnell Douglas Helicopter Systems...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-26

    ... distance between aft longeron rivets and the outboard edge of frame rings. If the distance is too short to... improperly installed frame ring at station 209.78. The frame rings were installed with too short a distance between an aft longeron rivet and the outboard edge of the frame ring. This is known as a...

  20. Bayesian reliability analysis in connection with the evaluation of multiple-site damage

    NASA Astrophysics Data System (ADS)

    Itagaki, Hiroshi; Asada, H.; Ito, S.

    A rivet splice model for analyzing multiple-site damage is presented. The effectiveness of the periodic inspection of multiple-site fatigue cracks along a rivet joint is discussed. The relative frequency distribution of visible crack length and joint posterior probability density are described.

  1. 78 FR 40072 - Airworthiness Directives; Eurocopter France Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-03

    ... rivets on the left-hand (LH) and right-hand (RH) Y350 longitudinal beams (longitudinal beams Y350). This...., Washington, DC 20590-0001. Hand Delivery: Deliver to the ``Mail'' address between 9 a.m. and 5 p.m., Monday... unsafe condition as non-conforming rivets installed on the left-hand (LH) and right-hand (RH)...

  2. 46 CFR 91.50-1 - Inspection and testing required when making alterations, repairs, or other such operations...

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ..., repairs, or other such operations involving riveting, welding, burning or like fire-producing actions. 91... testing required when making alterations, repairs, or other such operations involving riveting, welding..., welding, burning, or like fire-producing actions shall be made: (1) Within or on the boundaries of...

  3. 76 FR 27617 - Airworthiness Directives; Bombardier, Inc. Model DHC-8-400 Series Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-12

    .... Investigations revealed that loose rivets in the torque tube assemblies caused relative motion between the crank arms and torque tubes. Loose rivets could result in excessive wear and subsequent significant backlash.... For information on the availability of this material at the FAA, call 425-227-1221. Examining the...

  4. Fatigue strength of a single lap joint SPR-bonded

    NASA Astrophysics Data System (ADS)

    Di Franco, G.; Fratini, L.; Pasta, A.

    2011-05-01

    In the last years, hybrid joints, meaning with this the joints which consist in combining a traditional mechanical joint to a layer of adhesive, are gradually attracting the attention of various sectors of the construction of vehicles and transportation industries, for their better performance compared to just mechanical joints (self-piercing riveting SPR, riveting, and so on) or just to bonded joints. The paper investigates the fatigue behavior of a single lap joint self-piercing riveted (SPR) and bonded throughout fatigue tests. The considered geometric configuration allowed the use of two rivets placed longitudinally; an epoxy resin was used as adhesive. In the first part of the work static characterization of the joints was carried out through tensile tests. Then fatigue tests were made with the application of different levels of load. The fatigue curves were also obtained at the varying the distance between the two rivets in order to better assess the joint strength for a given length of overlap.

  5. Damage Tolerance of Integral Structure in Rotorcraft

    NASA Technical Reports Server (NTRS)

    Forth, Scott C.; Urban, Michael R.

    2003-01-01

    The rotorcraft industry has rapidly implemented integral structures into aircraft to benefit from the weight and cost advantages over traditionally riveted structure. The cost to manufacture an integral structure, where the entire component is machined from a single plate of material, is about one-fifth that of a riveted structure. Furthermore, the integral structure can weigh only one-half that of a riveted structure through optimal design of stiffening structure and part reduction. Finally, inspection and repair of damage in the field can be less costly than riveted structure. There are no rivet heads to inspect under, reducing inspection time, and damage can be removed or patched readily without altering the primary structure, reducing replacement or repair costs. In this paper, the authors will investigate the damage tolerance implications of fielding an integral structure manufactured from thick plate aluminum.

  6. Approaches for mechanical joining of 7xxx series aluminum alloys

    NASA Astrophysics Data System (ADS)

    Jäckel, M.; Grimm, T.; Landgrebe, D.

    2016-10-01

    This paper shows a numerical and experimental analysis of the different problems occurring during or after the conventional self-pierce riveting with semi-tubular and solid rivets of the high strength aluminum alloy EN AW-7021 T4. Furthermore this paper describes different pre-process methods by which the fracture in the high strength aluminum, caused by the self-pierce riveting processes, can be prevented and proper joining results are achieved. On this basis, the different approaches are compared regarding joint strength.

  7. The Growth of Multi-Site Fatigue Damage in Fuselage Lap Joints

    NASA Technical Reports Server (NTRS)

    Piascik, Robert S.; Willard, Scott A.

    1999-01-01

    Destructive examinations were performed to document the progression of multi-site damage (MSD) in three lap joint panels that were removed from a full scale fuselage test article that was tested to 60,000 full pressurization cycles. Similar fatigue crack growth characteristics were observed for small cracks (50 microns to 10 mm) emanating from counter bore rivets, straight shank rivets, and 100 deg counter sink rivets. Good correlation of the fatigue crack growth data base obtained in this study and FASTRAN Code predictions show that the growth of MSD in the fuselage lap joint structure can be predicted by fracture mechanics based methods.

  8. Joints of Articles made of Polymer Composite Materials

    DTIC Science & Technology

    2010-02-01

    joints analysis has shown that the most widely used aircraft joints are: – mechanical ones (bolted, screwed, riveted ); – pure adhesive; – combined...mechanical joints are recommended for joining articles with thickness more than 1.7 mm: – rivets can be used for thickness from 1.7 to 3.2 mm...case of single-side access. Possible variants of so-called “removable” fasteners (bolts or rivets ) are worked out too; – low-diameter fastener

  9. 6. NORTH END OF MACHINE SHOP. FORGE SHOP (HAER No. ...

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

    6. NORTH END OF MACHINE SHOP. FORGE SHOP (HAER No. CA-326-K) ON LEFT, FORD PLANT IN DISTANCE, NE BY 60. - Rosie the Riveter National Historical Park, Machine Shop, 1311 Canal Boulevard, Richmond, Contra Costa County, CA

  10. FROM LEFT TO RIGHT, 115, 117, 119, 121, 123, 125, ...

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

    FROM LEFT TO RIGHT, 115, 117, 119, 121, 123, 125, 127, 129 COLLINS STREET. ATCHISON VILLAGE HOUSED WORKERS DURING WORLD WAR II - Rosie the Riveter National Historical Park, Atchison Village, Collins Street, Richmond, Contra Costa County, CA

  11. 3. VIEW TO WEST SHOWING NORTHEAST SIDE OF BUILDING. NOTE ...

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

    3. VIEW TO WEST SHOWING NORTHEAST SIDE OF BUILDING. NOTE STIFFENING TRUSS OVER DOORWAY TO SUPPORT THE WALL. - Rosie the Riveter National Historical Park, Auxiliary Plate Shop, 912 Harbour Way, Richmond, Contra Costa County, CA

  12. 13. VIEW TO SOUTHEAST OF WAITING AREA SHOWING STAIRS TO ...

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

    13. VIEW TO SOUTHEAST OF WAITING AREA SHOWING STAIRS TO FIRST FLOOR (LEFT) AND HALL TO MANAGERS OFFICES (RIGHT). - Rosie the Riveter National Historical Park, Ford Assembly Plant, 1400 Harbour Way South, Richmond, Contra Costa County, CA

  13. 5. GENERAL WAREHOUSE, PERSPECTIVE VIEW TO NORTHWEST SHOWING FRONT ELEVATION ...

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

    5. GENERAL WAREHOUSE, PERSPECTIVE VIEW TO NORTHWEST SHOWING FRONT ELEVATION (LEFT) AND NORTH SIDE (RIGHT). - Rosie the Riveter National Historical Park, General Warehouse, 1320 Canal Boulevard, Richmond, Contra Costa County, CA

  14. 7. GENERAL WAREHOUSE, PERSPECTIVE VIEW TO NORTHWEST SHOWING FRONT ELEVATION ...

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

    7. GENERAL WAREHOUSE, PERSPECTIVE VIEW TO NORTHWEST SHOWING FRONT ELEVATION (LEFT) AND NORTH SIDE (RIGHT). - Rosie the Riveter National Historical Park, General Warehouse, 1320 Canal Boulevard, Richmond, Contra Costa County, CA

  15. 3. VIEW TO WEST SHOWING EAST END OF OIL HOUSE ...

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

    3. VIEW TO WEST SHOWING EAST END OF OIL HOUSE (LEFT) AND EAST SIDE OF CRATING SHED AND ASSEMBLY BUILDING (RIGHT BACKGROUND). - Rosie the Riveter National Historical Park, Ford Assembly Plant, 1400 Harbour Way South, Richmond, Contra Costa County, CA

  16. 7. VIEW TO NORTHEAST AT NORTHWEST END OF BUILDING. NOTE ...

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

    7. VIEW TO NORTHEAST AT NORTHWEST END OF BUILDING. NOTE CRANEWAY TRESTLE EXTENDING BEYOND END OF BUILDING. - Rosie the Riveter National Historical Park, Auxiliary Plate Shop, 912 Harbour Way, Richmond, Contra Costa County, CA

  17. 6. GENERAL WAREHOUSE, VIEW TO EAST SHOWING DETAIL OF ELEVATOR ...

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

    6. GENERAL WAREHOUSE, VIEW TO EAST SHOWING DETAIL OF ELEVATOR DOOR (CENTER), FLANKING PEDESTRIAN ENTRIES, AND LOADING DOCK. - Rosie the Riveter National Historical Park, General Warehouse, 1320 Canal Boulevard, Richmond, Contra Costa County, CA

  18. 14. VIEW TO SOUTHWEST AT NORTH END OF SECONDFLOOR ASSEMBLY ...

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

    14. VIEW TO SOUTHWEST AT NORTH END OF SECOND-FLOOR ASSEMBLY AREA. VIEW SHOWS DETAILS OF SAWTOOTH ROOF STRUCTURE. - Rosie the Riveter National Historical Park, Ford Assembly Plant, 1400 Harbour Way South, Richmond, Contra Costa County, CA

  19. 7. VIEW TO EAST SHOWING ELEVATION OF THE OFFICE PORTION ...

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

    7. VIEW TO EAST SHOWING ELEVATION OF THE OFFICE PORTION OF THE STRUCTURE AT NORTHWEST CORNER. - Rosie the Riveter National Historical Park, Ford Assembly Plant, 1400 Harbour Way South, Richmond, Contra Costa County, CA

  20. CAFETERIA AT SHIPYARD NO. 3, PERSPECTIVE VIEW TO NORTHWEST SHOWING ...

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

    CAFETERIA AT SHIPYARD NO. 3, PERSPECTIVE VIEW TO NORTHWEST SHOWING SOUTHEAST END AND FRONT SIDE (SHADED BY TREES) - Rosie the Riveter National Historical Park, Cafeteria, 1301 Canal Boulevard, Richmond, Contra Costa County, CA

  1. 1. VIEW TO NORTHEAST ACROSS RICHMOND INNER HARBOR FROM RICHMOND ...

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

    1. VIEW TO NORTHEAST ACROSS RICHMOND INNER HARBOR FROM RICHMOND SHIPYARD NO. 3. - Rosie the Riveter National Historical Park, Ford Assembly Plant, 1400 Harbour Way South, Richmond, Contra Costa County, CA

  2. 1. PERSPECTIVE VIEW TO WEST SHOWING SOUTHEAST END. NOTE THAT ...

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

    1. PERSPECTIVE VIEW TO WEST SHOWING SOUTHEAST END. NOTE THAT EXTERIOR CRANEWAY TRESTLES HAVE BEEN REDUCED IN LENGTH. - Rosie the Riveter National Historical Park, Auxiliary Plate Shop, 912 Harbour Way, Richmond, Contra Costa County, CA

  3. 4. GENERAL WAREHOUSE, PERSPECTIVE VIEW TO NORTHWEST SHOWING SOUTH SIDE ...

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

    4. GENERAL WAREHOUSE, PERSPECTIVE VIEW TO NORTHWEST SHOWING SOUTH SIDE (LEFT) AND FRONT ELEVATION (RIGHT). - Rosie the Riveter National Historical Park, General Warehouse, 1320 Canal Boulevard, Richmond, Contra Costa County, CA

  4. 4. VIEW TO EAST SHOWING WEST END OF CRANEWAY (CENTER), ...

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

    4. VIEW TO EAST SHOWING WEST END OF CRANEWAY (CENTER), WEST SIDE OF ASSEMBLY BUILDING (LEFT), AND WHARF (RIGHT). - Rosie the Riveter National Historical Park, Ford Assembly Plant, 1400 Harbour Way South, Richmond, Contra Costa County, CA

  5. 2. VIEW TO SOUTHWEST SHOWING OIL HOUSE (LEFT), BOILER ROOM ...

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

    2. VIEW TO SOUTHWEST SHOWING OIL HOUSE (LEFT), BOILER ROOM AND STACK (CENTER), ROOF OF CRANEWAY (BACKGROUND), AND CRATING SHED (RIGHT). - Rosie the Riveter National Historical Park, Ford Assembly Plant, 1400 Harbour Way South, Richmond, Contra Costa County, CA

  6. 9. VIEW TO SOUTHEAST ALONG THE LENGTH OF THE SOUTHWEST ...

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

    9. VIEW TO SOUTHEAST ALONG THE LENGTH OF THE SOUTHWEST SIDE BAY. NOTE WORK AREAS IN LEAN-TO BAYS ALONG RIGHT SIDE. - Rosie the Riveter National Historical Park, Auxiliary Plate Shop, 912 Harbour Way, Richmond, Contra Costa County, CA

  7. 40 CFR 205.158 - Labeling requirements.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... distributed in commerce. (2) The label must be plastic or metal and be welded, riveted, or otherwise... Califfo CAL Carabela CAR Cimatti CIM Columbia COL E-Z Rider EZR Flying Dutchman FLY Foxi FOI Gadabout...

  8. 49 CFR 179.200-22 - Test of tanks.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... minutes without leakage or evidence of distress. All rivets and closures, except safety relief valves or... welded joints to stop leaks developed during the foregoing tests is prohibited. Repairs in welded...

  9. 77 FR 50644 - Airworthiness Directives; Cessna Airplane Company Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-22

    ...) 1134104-1 A/C compressor motors. When the brush wears down, the rivet in the brush contacts the commutator... Joint Aircraft System Component (JASC)/Air Transport Association (ATA) of America Code 21,...

  10. 17. MARINA WAY, HARBOUR WAY, AND MARITIME CHILD DEVELOPMENT CENTER ...

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

    17. MARINA WAY, HARBOUR WAY, AND MARITIME CHILD DEVELOPMENT CENTER (SEE ALSO HABS No. CA-2718), WITH RICHMOND SHIPYARD NO. 3. S. - Rosie the Riveter National Historical Park, 1401 Marina Way South, Richmond, Contra Costa County, CA

  11. 3. GENERAL VIEW OF BOILER ROOM, LOOKING NORTH; CONTROL PANEL ...

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

    3. GENERAL VIEW OF BOILER ROOM, LOOKING NORTH; CONTROL PANEL AT CENTER; BOXLIKE, RIVETED HOUSING AT TOP CENTER CONTAINED AUGER FOR COAL DISTRIBUTION SYSTEM - Rath Packing Company, Boiler Room, Sycamore Street between Elm & Eighteenth Streets, Waterloo, Black Hawk County, IA

  12. Counting Lattice-Gas Invariants

    DTIC Science & Technology

    2007-11-02

    Dominique d’Humières, Brosl Hasslacher, Pierre Lallemand, Yves Pomeau, and Jean-Pierre Rivet . Lattice gas hydrodynamics in two and three dimensions...177. Springer -Verlag, Februrary 1989. Proceedings of the Winter School, Les Houches, France. 6

  13. 6. Detail of central Samson post showing portal struts and ...

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

    6. Detail of central Samson post showing portal struts and paired stay rods; note riveted girder at bottom center; view to southeast. - Summer Street Bridge, Spanning Reserved Channel, Boston, Suffolk County, MA

  14. PANORAMIC VIEW OF SHIPYARD NO. 3, LOOKING SOUTHEAST. FIRST AID ...

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

    PANORAMIC VIEW OF SHIPYARD NO. 3, LOOKING SOUTHEAST. FIRST AID STATION AT CENTER LEFT AND FORGE SHOP AT RIGHT - Rosie the Riveter National Historical Park, Richmond Shipyard No. 3, Point Potrero, Richmond, Contra Costa County, CA

  15. 12. DETAIL VIEW SHOWING HIP VERTICAL, INCLINED ENDPOST, PORTAL BRACING, ...

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

    12. DETAIL VIEW SHOWING HIP VERTICAL, INCLINED ENDPOST, PORTAL BRACING, TOP CHORD, SOUTHWEST CORNER OF SOUTH TRUSS (RIVETED CONNECTION) - Marathon City Bridge, Spanning Big Rib River, on state Trunk Highway 107, Marathon, Marathon County, WI

  16. 46 CFR 59.15-10 - Bagged or blistered shell plates.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... portion to be cut away and the shell repaired by fitting a patch of steel plate conforming to the... riveting schedule of the patch is so arranged as to give the plate sufficient strength to withstand...

  17. 46 CFR 59.15-10 - Bagged or blistered shell plates.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... portion to be cut away and the shell repaired by fitting a patch of steel plate conforming to the... riveting schedule of the patch is so arranged as to give the plate sufficient strength to withstand...

  18. 29 CFR Appendix B to Subpart B of... - Reprint of U.S. Coast Guard Regulations Referenced in Subpart B, for Determination of Coast Guard...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) OCCUPATIONAL SAFETY AND HEALTH STANDARDS FOR SHIPYARD EMPLOYMENT Confined and... safety, no alterations, repairs, or other such operations involving riveting, welding, burning, or...

  19. An examination of faying surface fretting in single lap splices

    NASA Astrophysics Data System (ADS)

    Brown, Adam

    While fretting damage in mechanically fastened joints is widely acknowledged as a common source of crack nucleation, little work is available in the open literature on the role that fretting damage plays in the fatigue life of a riveted joint. To expand on the limited knowledge available, a study was undertaken on fretting fatigue in thin-sheet riveted fuselage lap joints. In joints constructed out of 1 mm thick 2024-T3 aluminum sheet the rivet forming load was found to have a significant effect on the location of fretting damage and crack nucleation. This effect was observed for splices riveted with machine countersunk and with universal rivets. The shift in the location of peak fretting damage and crack nucleation with changing rivet forming loads was investigated through numerical and experimental methods. A predictive model based on the critical plane Smith-Watson-Topper strain life equation was applied to the complex geometry of the single lap splice and was shown to be effective in predicting the fretting fatigue life as well as the location of fretting-induced crack nucleation. Basing this model on an explicit finite element simulation allowed for the inclusion of compressive residual stresses generated during rivet forming. Key to the proper functionality of the predictive model was to have a validated finite element model from which results for the stress and strain field in the loaded component could be obtained. In addition to the predictive model, a series of splice coupon and simplified geometry fretting fatigue tests were performed. The tests showed that, at higher rivet forming loads, crack nucleation is on the faying surface away from the hole edge and that the type of surface condition is important to the fretting fatigue life of the splice. The discovery of this variation with surface treatment at high rivet forming loads is important as more research is showing the benefit of using load-controlled rivet forming and higher rivet forming loads in

  20. Powertrain Embedded Diagnostic and Predictive Capability for an Automotive Transmission

    DTIC Science & Technology

    2012-08-01

    lock- washer, riveted to the 3rd range planetary sun gear had also been damaged during the testing. The rivets were sheared off by a sharp edge of... gear -path and the mechanical gear path to the output planetary ring gears . This creates a torsional shock that is probably difficult to estimate and...transmissions were operated around the clock under the most demanding speed and load set-points until critical gear or bearing failures resulted in loss

  1. Cathodic Protection of Hot Water Tanks at Fort Sill

    DTIC Science & Technology

    2007-06-01

    should be flat against the material. Bent rivets will fail under stress . Especially note condition of Dee Ring rivets and Dee Ring metal wear pads...free fall distance. Also, to be stressed are the importance of inspections prior to use, the limitations of the equipment, and unique conditions at...devices during the force test; d. Caution statements on critical use limitations; e. Application limits; f. Proper hook -up, anchoring and tie-off

  2. Hot-Spot Fatigue and Impact Damage Detection on a Helicopter Tailboom

    DTIC Science & Technology

    2011-09-01

    developed based on the principle of using the passive mode as a self - trigger mechanism to scan the structure (Figure 1). The passive mode process...monitoring areas were defined at the joint of the horizontal stabilizer on the tailboom structure, as shown in Figure 4. Figure 3...from the 4 rivets determined by Bell Helicopter; 8 PZT disks were placed around another 4 rivets to detect any possible cracks initiated from these

  3. Evaluation of the fuselage lap joint fatigue and terminating action repair

    NASA Astrophysics Data System (ADS)

    Samavedam, Gopal; Thomson, Douglas; Jeong, David Y.

    1994-09-01

    Terminating action is a remedial repair which entails the replacement of shear head countersunk rivets with universal head rivets which have a larger shank diameter. The procedure was developed to eliminate the risk of widespread fatigue damage (WFD) in the upper rivet row of a fuselage lap joint. A test and evaluation program has been conducted by Foster-Miller, Inc. (FMI) to evaluate the terminating action repair of the upper rivet row of a commercial aircraft fuselage lap splice. Two full scale fatigue tests were conducted on fuselage panels using the growth of fatigue cracks in the lap joint. The second test was performed to evaluate the effectiveness of the terminating action repair. In both tests, cyclic pressurization loading was applied to the panels while crack propagation was recorded at all rivet locations at regular intervals to generate detailed data on conditions of fatigue crack initiation, ligament link-up, and fuselage fracture. This program demonstrated that the terminating action repair substantially increases the fatigue life of a fuselage panel structure and effectively eliminates the occurrence of cracking in the upper rivet row of the lap joint. While high cycle crack growth was recorded in the middle rivet row during the second test, failure was not imminent when the test was terminated after cycling to well beyond the service life. The program also demonstrated that the initiation, propagation, and linkup of WFD in full-scale fuselage structures can be simulated and quantitatively studied in the laboratory. This paper presents an overview of the testing program and provides a detailed discussion of the data analysis and results. Crack distribution and propagation rates and directions as well as frequency of cracking are presented for both tests. The progression of damage to linkup of adjacent cracks and to eventual overall panel failure is discussed. In addition, an assessment of the effectiveness of the terminating action repair and the

  4. Finite Element and Analytical Analysis of Cracks in Thick Stiffened Plates Repaired with a Single Sided Composite Patch

    DTIC Science & Technology

    2014-06-01

    Figure 11   Smeared Composite Patched Plate ...................................................................21 Figure 12   Single Side Strap Joint ... riveting an additional reinforcement onto the damaged area. This would create new defects and stress concentrations which could lead to additional...stiffener that has been riveted , a welded stiffener can allow a crack to propagate through, causing failure in both the plate and the stiffener [13]. The

  5. Manned Airborne Intelligence, Surveillance, and Reconnaissance: Strategic, Tactical . . . Both?

    DTIC Science & Technology

    2012-12-01

    hours in the RC-135 Rivet Joint . Major Morton is pursuing a PhD through Air University; his dissertation is a historical analysis of the evolution of...collection, Larson’s team members began to look for more platforms that could contribute.46 Visiting the RC-135M Rivet Card crews in Ja- pan, they discovered...continued until Operation Urgent Fury in Grenada again underscored the inabil- ity to deliver tactical intelligence to joint ground customers.53 After

  6. Synthetic Infrared Scene: Improving the KARMA IRSG Module and Signature Modelling Tool SMAT

    DTIC Science & Technology

    2011-03-01

    Desmeules Alexandre Bastien Louis Tanguay Informatique inc. Geoffroy Rivet-Sabourin Technologie Intelligence Image inc. Prepared By: Louis Tanguay... Informatique inc. 825 Boulevard Lebourgneuf, Bureau 204 Québec, Canada G2J 0B9 Contractor’s Document Number: LTI-SIS-2011-1 Contract Project Manager...Alexandre Bastien Louis Tanguay Informatique inc. Geoffroy Rivet-Sabourin Technologie Intelligence Image inc. Prepared By: Louis Tanguay

  7. Joining of Components of Complex Structures for Improved Dynamic Response

    DTIC Science & Technology

    2011-10-28

    rivets , etc. The locations (assembly points) of these joints affect structural perfor- mance characteristics such as the static compliance, the...to each other. In this work, it is assumed that kx,i = kz,i = αiki and ky,i = ki. This is the case for joints such as bolts, rivets , spot welds, etc...P. Bendsøe, O. Sigmund, Topology Optimization: Theory, Methods and Applications, Springer , 2002. 23 [6] M. Chirehdast, T. Jiang, Optimal design of

  8. Evaluation of the fuselage lap joint fatigue and terminating action repair

    NASA Technical Reports Server (NTRS)

    Samavedam, Gopal; Thomson, Douglas; Jeong, David Y.

    1994-01-01

    Terminating action is a remedial repair which entails the replacement of shear head countersunk rivets with universal head rivets which have a larger shank diameter. The procedure was developed to eliminate the risk of widespread fatigue damage (WFD) in the upper rivet row of a fuselage lap joint. A test and evaluation program has been conducted by Foster-Miller, Inc. (FMI) to evaluate the terminating action repair of the upper rivet row of a commercial aircraft fuselage lap splice. Two full scale fatigue tests were conducted on fuselage panels using the growth of fatigue cracks in the lap joint. The second test was performed to evaluate the effectiveness of the terminating action repair. In both tests, cyclic pressurization loading was applied to the panels while crack propagation was recorded at all rivet locations at regular intervals to generate detailed data on conditions of fatigue crack initiation, ligament link-up, and fuselage fracture. This program demonstrated that the terminating action repair substantially increases the fatigue life of a fuselage panel structure and effectively eliminates the occurrence of cracking in the upper rivet row of the lap joint. While high cycle crack growth was recorded in the middle rivet row during the second test, failure was not imminent when the test was terminated after cycling to well beyond the service life. The program also demonstrated that the initiation, propagation, and linkup of WFD in full-scale fuselage structures can be simulated and quantitatively studied in the laboratory. This paper presents an overview of the testing program and provides a detailed discussion of the data analysis and results. Crack distribution and propagation rates and directions as well as frequency of cracking are presented for both tests. The progression of damage to linkup of adjacent cracks and to eventual overall panel failure is discussed. In addition, an assessment of the effectiveness of the terminating action repair and the

  9. Merging Imagery and Models for River Current Prediction

    DTIC Science & Technology

    2011-01-01

    imagery. Snohomish Rivet 1. INTRODUCTION River operations are rapidly becoming a major part of Military Special Operations, yet rivers pose one of...yet minimal. input for the RST is I ollet ted from the user to facilitate specification of upstream and downstream forcing and frictional effects of...point extraction process for the Snohomish Rivet W \\ 2.2 Shoreline Processing I’sing the water and edge point data obtained from the imagery, a

  10. Fracture analysis of multi-site cracking in fuselage lap joints

    NASA Astrophysics Data System (ADS)

    Beuth, J. L.; Hutchinson, J. W.

    1994-09-01

    A two-dimensional plane stress elastic fracture mechanics analysis of a cracked lap joint fastened by rigid pins is presented and results are applied to the problem of multi-site damage (MSD) in riveted lap joints of aircraft fuselage skins. Two problems are addressed, the problem of equal length MSD cracks and the problem of alternating length MSD cracks. For the problem of equal length cracks, two models of rivet/skin interactions are studied and the role of residual stresses due to the riveting process is explored. Stress intensity factors are obtained as a function of normalized crack length. Also, the load distribution among rivet rows and the compliance change of the joint due to MSD cracking are obtained. For the problem of alternating length cracks, attention is focussed on how load is distributed between columns of rivets and how this load shedding can alter crack tip stress intensity factors. The equal and alternating length crack analyses reveal no clear-cut mechanism to explain the relative uniformity of fatigue cracks emerging from lap joint rivet holes in actual aircraft and in mechanical lap joint tests.

  11. Model-based study for evaluating the sensitivity of eddy current GMR probe inspection of multilayer structures

    NASA Astrophysics Data System (ADS)

    Su, Zhiyi; Rosell, Anders; Udpa, Lalita; Tamburrino, Antonello

    2017-02-01

    In eddy current nondestructive testing (EC-NDT) of a multilayer riveted structure, rotating current excitation, generated by orthogonal coils, is advantageous in providing sensitivity to defects of all orientations. The signal of a defect is not only a function of its size but also of the geometrical features in vicinity to the rivet such as edges, adjacent rivets and properties of the layered structure. Numerical models can be used to provide fast and accurate estimates of defect signals. In this paper the sensitivity of the eddy current system with rotating current excitation and GMR sensors is evaluated by considering the effect of rivet permeability, lift-off, thickness of first layer as well as defect orientation related to adjacent rivets and edges on the signal measured. A numerical model capable of simulating these combinations of defect and test geometry parameters at an acceptable computation time is used. A meta-model is developed based on these simulation results and utilized for sensitivity evaluation.

  12. Automatic Fastening Large Structures: a New Approach

    NASA Technical Reports Server (NTRS)

    Lumley, D. F.

    1985-01-01

    The external tank (ET) intertank structure for the space shuttle, a 27.5 ft diameter 22.5 ft long externally stiffened mechanically fastened skin-stringer-frame structure, was a labor intensitive manual structure built on a modified Saturn tooling position. A new approach was developed based on half-section subassemblies. The heart of this manufacturing approach will be 33 ft high vertical automatic riveting system with a 28 ft rotary positioner coming on-line in mid 1985. The Automatic Riveting System incorporates many of the latest automatic riveting technologies. Key features include: vertical columns with two sets of independently operating CNC drill-riveting heads; capability of drill, insert and upset any one piece fastener up to 3/8 inch diameter including slugs without displacing the workpiece offset bucking ram with programmable rotation and deep retraction; vision system for automatic parts program re-synchronization and part edge margin control; and an automatic rivet selection/handling system.

  13. Fatigue strength of a single lap joint SPR-bonded

    SciTech Connect

    Di Franco, G.; Fratini, L.; Pasta, A.

    2011-05-04

    In the last years, hybrid joints, meaning with this the joints which consist in combining a traditional mechanical joint to a layer of adhesive, are gradually attracting the attention of various sectors of the construction of vehicles and transportation industries, for their better performance compared to just mechanical joints (self-piercing riveting SPR, riveting, and so on) or just to bonded joints.The paper investigates the fatigue behavior of a single lap joint self-piercing riveted (SPR) and bonded throughout fatigue tests. The considered geometric configuration allowed the use of two rivets placed longitudinally; an epoxy resin was used as adhesive. In the first part of the work static characterization of the joints was carried out through tensile tests. Then fatigue tests were made with the application of different levels of load. The fatigue curves were also obtained at the varying the distance between the two rivets in order to better assess the joint strength for a given length of overlap.

  14. Detection of tightness of mechanical joints using lock-in thermography

    NASA Astrophysics Data System (ADS)

    Zweschper, Thomas; Wu, Datong; Busse, Gerhard

    1999-09-01

    Lockin thermography is currently being used for the rapid and remote identification of subsurface structures and defects such as impact damages, delaminations, and hidden corrosion. The purpose of this paper is to show that lockin thermography is also a reliable tool to inspect in a remote way the tightness of mechanical joints in safety relevant structures (e.g. aerospace equipment and vehicles). For example, the rapid identification of loose rivets is a major concern for airlines and manufacturers in order to monitor the structural integrity of their aircraft. Our measurements aimed at the early detection of loose rivets. We analyzed the phase image signature obtained on two metal plates pressed together by screws fastened at various torque levels. A clear relationship was established between phase angle and torque level at which the screws had been fastened. Based on these results our investigations were extended to riveted samples where two aluminum plates were pressed together by an array of ten blind rivets. Also in this case the level of tightness of rivet joints can be detected. In addition to these feasibility studies on model samples, we performed investigations on airplane components which confirmed the applicability of lockin thermography for remote maintenance inspection within a few minutes.

  15. Flux-focusing eddy current probe and rotating probe method for flaw detection

    NASA Astrophysics Data System (ADS)

    Wincheski, Buzz A.; Fulton, James P.; Nath, Shridhar C.; Simpson, John W.; Namkung, Min

    1994-11-01

    A flux-focusing electromagnetic sensor which uses a ferromagnetic flux-focusing lens simplifies inspections and increases detectability of fatigue cracks about circular fasteners and other circular inhomogeneities in high conductivity material. The unique feature of the device is the ferrous shield isolating a high-turn pick-up coil from an excitation coil. The use of the magnetic shield is shown to produce a null voltage output across the receiving coil in the presence of an unflawed sample. A redistribution of the current flow in the sample caused by the presence of flaws, however, eliminates the shielding condition and a large output voltage is produced, yielding a clear unambiguous flaw signal. By rotating the probe in a path around a circular fastener such as a rivet while maintaining a constant distance between the probe and the center of a rivet, the signal due to current flow about the rivet can be held constant. Any further changes in the current distribution, such as due to a fatigue crack at the rivet joint, can be detected as an increase in the output voltage above that due to the flow about the rivet head.

  16. Rotating flux-focusing eddy current probe for flaw detection

    NASA Technical Reports Server (NTRS)

    Wincheski, Russell A. (Inventor); Fulton, James P. (Inventor); Nath, Shridhar C. (Inventor); Simpson, John W. (Inventor); Namkung, Min (Inventor)

    1997-01-01

    A flux-focusing electromagnetic sensor which uses a ferromagnetic flux-focusing lens simplifies inspections and increases detectability of fatigue cracks about circular fasteners and other circular inhomogeneities in high conductivity material. The unique feature of the device is the ferrous shield isolating a high-turn pick-up coil from an excitation coil, The use of the magnetic shield is shown to produce a null voltage output across the receiving coil in the presence of an unflawed sample. A redistribution of the current flow in the sample caused by the presence of flaws, however, eliminates the shielding condition and a large output voltage is produced, yielding a clear unambiguous flaw signal. By rotating the probe in a path around a circular fastener such as a rivet while maintaining a constant distance between the probe and the center of a rivet, the signal due to current flow about the rivet can be held constant. Any further changes in the current distribution, such as due to a fatigue crack at the rivet joint, can be detected as an increase in the output voltage above that due to the flow about the rivet head.

  17. The Effects of Some Surface Irregularities on Wing Drag

    NASA Technical Reports Server (NTRS)

    Drag, Manley

    1939-01-01

    The N.A.C.A. has conducted tests to provide more complete data than were previously available for estimating the effects of common surface irregularities on wing drag. The irregularities investigated included: brazier-head and countersunk rivets, spot welds, several types of sheet-metal joints, and surface roughness. Tests were also conducted to determine the over-all effect of manufacturing irregularities incidental to riveted aluminum alloy and to spot-welded stainless-steel construction. The tests were made in the 8-foot high speed wind tunnel at Reynolds Numbers up to 18,000,000. The results show that any of the surface irregularities investigated may increase wing drag enough to have important adverse effects on high-speed performance and economy. A method of estimating increases in wing drag caused by brazier-head rivets and lapped joints under conditions outside the range of the tests is suggested. Estimated drag increases due to rivets and lapped joints under conditions outside the range of the tests is suggested. Estimated drag increases due to rivets and lapped joints on a wing of 20-foot chord flying at 250 miles per hour are shown.

  18. Finite Element Modeling and Optimization of Mechanical Joining Technology

    NASA Astrophysics Data System (ADS)

    Chenot, Jean-Loup; Bouchard, Pierre-Olivier; Massoni, Elisabeth; Mocellin, Katia; Lasne, Patrice

    2011-05-01

    The main scientific ingredients are recalled for developing a general finite element code and model accurately large plastic deformation of metallic materials during joining processes. Multi material contact is treated using the classical master and slave approach. Rupture may occur in joining processes or even be imposed in self piercing riveting and it must be predicted to evaluate the ultimate strength of joins. Damage is introduced with a generalized uncoupled damage criterion, or by utilizing a coupled formulation with a Lemaître law. Several joining processes are briefly analyzed in term of specific scientific issues: riveting, self piercing riveting, clinching, crimping, hemming and screwing. It is shown that not only the joining process can be successfully simulated and optimized, but also the strength of the assembly can be predicted in tension and in shearing.

  19. Operationally Responsive Space (ORS): An Architecture and Enterprise Model for Adaptive Integration, Test and Logistics

    DTIC Science & Technology

    2008-06-01

    1 3 0 0 0 0 0 0 0 0 0 1 2 0 3 3 3 27 RQ4 Global Hawk 3.5 3. 5 3.5 3.5 1 1 1 1 3.5 0 0 0 0 0 0 0 0 0 1 2 0 3 3 3 33.5 RC135 V/W Rivet Joint 2.5...embedded ground communications equipment; a support element; and trained personnel. E.4 RC-135V/W Rivet Joint The RC-135V/W sensor suite allows the...210 cockpit crew, electronic warfare officers, intelligence operators and airborne systems engineers. Figure E-E-2. An RC-135 Rivet Joint

  20. Rotating concave eddy current probe

    DOEpatents

    Roach, Dennis P.; Walkington, Phil; Rackow, Kirk A.; Hohman, Ed

    2008-04-01

    A rotating concave eddy current probe for detecting fatigue cracks hidden from view underneath the head of a raised head fastener, such as a buttonhead-type rivet, used to join together structural skins, such as aluminum aircraft skins. The probe has a recessed concave dimple in its bottom surface that closely conforms to the shape of the raised head. The concave dimple holds the probe in good alignment on top of the rivet while the probe is rotated around the rivet's centerline. One or more magnetic coils are rigidly embedded within the probe's cylindrical body, which is made of a non-conducting material. This design overcomes the inspection impediment associated with widely varying conductivity in fastened joints.

  1. Preliminary results on the fracture analysis of multi-site cracking of lap joints in aircraft skins

    NASA Astrophysics Data System (ADS)

    Beuth, J. L., Jr.; Hutchinson, John W.

    1992-07-01

    Results of a fracture mechanics analysis relevant to fatigue crack growth at rivets in lap joints of aircraft skins are presented. Multi-site damage (MSD) is receiving increased attention within the context of problems of aging aircraft. Fracture analyses previously carried out include small-scale modeling of rivet/skin interactions, larger-scale two-dimensional models of lap joints similar to that developed here, and full scale three-dimensional models of large portions of the aircraft fuselage. Fatigue testing efforts have included flat coupon specimens, two-dimensional lap joint tests, and full scale tests on specimens designed to closely duplicate aircraft sections. Most of this work is documented in the proceedings of previous symposia on the aging aircraft problem. The effect MSD has on the ability of skin stiffeners to arrest the growth of long skin cracks is a particularly important topic that remains to be addressed. One of the most striking features of MSD observed in joints of some test sections and in the joints of some of the older aircraft fuselages is the relative uniformity of the fatigue cracks from rivet to rivet along an extended row of rivets. This regularity suggests that nucleation of the cracks must not be overly difficult. Moreover, it indicates that there is some mechanism which keeps longer cracks from running away from shorter ones, or, equivalently, a mechanism for shorter cracks to catch-up with longer cracks. This basic mechanism has not been identified, and one of the objectives of the work is to see to what extent the mechanism is revealed by a fracture analysis of the MSD cracks. Another related aim is to present accurate stress intensity factor variations with crack length which can be used to estimate fatigue crack growth lifetimes once cracks have been initiated. Results are presented which illustrate the influence of load shedding from rivets with long cracks to neighboring rivets with shorter cracks. Results are also included

  2. Development of shearography for nondestructive testing of highway structure

    NASA Astrophysics Data System (ADS)

    Hung, Y. Y.; Hovanesian, J. D.

    1984-06-01

    Testing methodologies which may lead to early detection of impending structural failures are developed. The research is aimed at a laboratory feasibility study of an optical technique known as SHEAROGRAPHY for nondestructive testing of highway structural members. Laboratory samples representing typical highway structural members with programmed defects are tested with shearography. These samples include tubular member with an internal crack, butt weld joint with an imperfection in the weld, riveted joint with a loosened rivet, steel reinforced concrete slab with a broken internal reinforcement rod, and cord reinforced composite plate with the delaminations. All the programmed defects are detectable by shearography.

  3. Preliminary results on the fracture analysis of multi-site cracking of lap joints in aircraft skins

    NASA Technical Reports Server (NTRS)

    Beuth, J. L., Jr.; Hutchinson, John W.

    1992-01-01

    Results of a fracture mechanics analysis relevant to fatigue crack growth at rivets in lap joints of aircraft skins are presented. Multi-site damage (MSD) is receiving increased attention within the context of problems of aging aircraft. Fracture analyses previously carried out include small-scale modeling of rivet/skin interactions, larger-scale two-dimensional models of lap joints similar to that developed here, and full scale three-dimensional models of large portions of the aircraft fuselage. Fatigue testing efforts have included flat coupon specimens, two-dimensional lap joint tests, and full scale tests on specimens designed to closely duplicate aircraft sections. Most of this work is documented in the proceedings of previous symposia on the aging aircraft problem. The effect MSD has on the ability of skin stiffeners to arrest the growth of long skin cracks is a particularly important topic that remains to be addressed. One of the most striking features of MSD observed in joints of some test sections and in the joints of some of the older aircraft fuselages is the relative uniformity of the fatigue cracks from rivet to rivet along an extended row of rivets. This regularity suggests that nucleation of the cracks must not be overly difficult. Moreover, it indicates that there is some mechanism which keeps longer cracks from running away from shorter ones, or, equivalently, a mechanism for shorter cracks to catch-up with longer cracks. This basic mechanism has not been identified, and one of the objectives of the work is to see to what extent the mechanism is revealed by a fracture analysis of the MSD cracks. Another related aim is to present accurate stress intensity factor variations with crack length which can be used to estimate fatigue crack growth lifetimes once cracks have been initiated. Results are presented which illustrate the influence of load shedding from rivets with long cracks to neighboring rivets with shorter cracks. Results are also included

  4. Standard Waste Box Lid Screw Removal Option Testing

    SciTech Connect

    Anast, Kurt Roy

    2016-03-11

    This report provides results from test work conducted to resolve the removal of screws securing the standard waste box (SWB) lids that hold the remediated nitrate salt (RNS) drums. The test work evaluated equipment and process alternatives for removing the 42 screws that hold the SWB lid in place. The screws were secured with a red Loctite thread locker that makes removal very difficult because the rivets that the screw threads into would slip before the screw could be freed from the rivet, making it impossible to remove the screw and therefore the SWB lid.

  5. View of north tower base panel and portion of concrete ...

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

    View of north tower base panel and portion of concrete abutment. Note riveted construction and dual-wire rope connections from counterweight to lift span on both sides. Lift wire ropes have been removed. - Potomac Edison Company, Chesapeake & Ohio Canal Bridge, Spanning C & O Canal South of U.S. 11, Williamsport, Washington County, MD

  6. 77 FR 3382 - Airworthiness Directives; Agusta S.p.A. Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-24

    ...-27-08] RIN 2120-AA64 Airworthiness Directives; Agusta S.p.A. Helicopters AGENCY: Federal Aviation... are adopting a new airworthiness directive (AD) for all Agusta S.p.A. (Agusta) model A109S and AW109SP helicopters. This AD is prompted by a fatigue crack found in the left elevator assembly along the riveting...

  7. 76 FR 40217 - Airworthiness Directives; Rolls-Royce plc (RR) RB211-524 Series Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-08

    ... Engines AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Final rule; request for comments... stubshaft fracture and the subsequent repair of the fixed structure to Engine Manual repair No. FRS5887... failure of the attachment rivets resulting in loss of engine structural integrity, which may result...

  8. MACHINE SHOP AT SHIPYARD NO. 3, VIEW TO WESTSOUTHWEST OF ...

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

    MACHINE SHOP AT SHIPYARD NO. 3, VIEW TO WEST-SOUTHWEST OF THE EAST ELEVATION. LOOKING ACROSS THE RICHMOND INNER HARBOR FROM NEAR THE FORD ASSEMBLY BUILDING - Rosie the Riveter National Historical Park, Machine Shop, 1311 Canal Boulevard, Richmond, Contra Costa County, CA

  9. MACHINE SHOP, PERSPECTIVE VIEW TO NORTHNORTHEAST OF THE WEST SIDE ...

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

    MACHINE SHOP, PERSPECTIVE VIEW TO NORTH-NORTHEAST OF THE WEST SIDE AND SOUTH END. WEST (REAR) SIDE OF GENERAL WAREHOUSE IS IN RIGHT FOREGROUND - Rosie the Riveter National Historical Park, Machine Shop, 1311 Canal Boulevard, Richmond, Contra Costa County, CA

  10. 29 CFR 1910.217 - Mechanical power presses.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... OCCUPATIONAL SAFETY AND HEALTH STANDARDS Machinery and Machine Guarding § 1910.217 Mechanical power presses. (a... this section. (5) Excluded machines. Press brakes, hydraulic and pneumatic power presses, bulldozers, hot bending and hot metal presses, forging presses and hammers, riveting machines and similar types...

  11. 29 CFR 1910.217 - Mechanical power presses.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... OCCUPATIONAL SAFETY AND HEALTH STANDARDS Machinery and Machine Guarding § 1910.217 Mechanical power presses. (a... this section. (5) Excluded machines. Press brakes, hydraulic and pneumatic power presses, bulldozers, hot bending and hot metal presses, forging presses and hammers, riveting machines and similar types...

  12. 29 CFR 1910.217 - Mechanical power presses.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... OCCUPATIONAL SAFETY AND HEALTH STANDARDS Machinery and Machine Guarding § 1910.217 Mechanical power presses. (a... this section. (5) Excluded machines. Press brakes, hydraulic and pneumatic power presses, bulldozers, hot bending and hot metal presses, forging presses and hammers, riveting machines and similar types...

  13. 29 CFR 1910.217 - Mechanical power presses.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... OCCUPATIONAL SAFETY AND HEALTH STANDARDS Machinery and Machine Guarding § 1910.217 Mechanical power presses. (a... this section. (5) Excluded machines. Press brakes, hydraulic and pneumatic power presses, bulldozers, hot bending and hot metal presses, forging presses and hammers, riveting machines and similar types...

  14. 18 CFR 367.3940 - Account 394, Tools, shop and garage equipment.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    .... (17) Gasoline pumps, oil pumps and storage tanks. (18) Greasing tools and equipment. (19) Hoists. (20) Ladders. (21) Lathes. (22) Machine tools. (23) Motor-driven tools. (24) Motors. (25) Pipe threading and cutting tools. (26) Pneumatic tools. (27) Pumps. (28) Riveters. (29) Smithing equipment. (30) Tool...

  15. 18 CFR 367.3940 - Account 394, Tools, shop and garage equipment.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    .... (17) Gasoline pumps, oil pumps and storage tanks. (18) Greasing tools and equipment. (19) Hoists. (20) Ladders. (21) Lathes. (22) Machine tools. (23) Motor-driven tools. (24) Motors. (25) Pipe threading and cutting tools. (26) Pneumatic tools. (27) Pumps. (28) Riveters. (29) Smithing equipment. (30) Tool...

  16. 18 CFR 367.3940 - Account 394, Tools, shop and garage equipment.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    .... (17) Gasoline pumps, oil pumps and storage tanks. (18) Greasing tools and equipment. (19) Hoists. (20) Ladders. (21) Lathes. (22) Machine tools. (23) Motor-driven tools. (24) Motors. (25) Pipe threading and cutting tools. (26) Pneumatic tools. (27) Pumps. (28) Riveters. (29) Smithing equipment. (30) Tool...

  17. 18 CFR 367.3940 - Account 394, Tools, shop and garage equipment.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    .... (17) Gasoline pumps, oil pumps and storage tanks. (18) Greasing tools and equipment. (19) Hoists. (20) Ladders. (21) Lathes. (22) Machine tools. (23) Motor-driven tools. (24) Motors. (25) Pipe threading and cutting tools. (26) Pneumatic tools. (27) Pumps. (28) Riveters. (29) Smithing equipment. (30) Tool...

  18. MARINA & MAINE STREETS FACING NW. DARKER COLORED HOME ON ...

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

    MARINA & MAINE STREETS FACING NW. DARKER COLORED HOME ON SE CORNER. NYSTROM VILLAGE, LIKE ATCHISON VILLAGE (HAER CA-326-N), HOUSED WORKERS DURING WORLD WAR II - Rosie the Riveter National Historical Park, Nystrom Village, Marina & Maine Streets, Richmond, Contra Costa County, CA

  19. Civil Rights Milestones Offer Lessons

    ERIC Educational Resources Information Center

    Malveaux, Julianne

    2004-01-01

    The landmark legal decision, Brown v. Board of Education, was rendered on May 17, 1954. Fifty years later, campuses and communities are commemorating the decision and its impact on contemporary life. The Harvard legal scholar, Charles Ogletree, has published a riveting book of his reflections, a government commission is staging a variety of…

  20. Best Reference 2008

    ERIC Educational Resources Information Center

    Coutts, Brian E.; LaGuardia, Cheryl

    2009-01-01

    America's subprime mortgage crisis of 2007 spiraled into a global financial crisis in 2008. For much of the year, attention was riveted on the presidential primaries. A worsening economy made the election somewhat anticlimactic, but everybody rejoiced with the choice of the first "international" President. With stocks tumbling and major firms…

  1. Pre-Coated Fasteners

    DTIC Science & Technology

    2008-02-01

    Issues • Equivalent to and/or improved corrosion protection from a “dry” ready-to-use fastener • Elimination of hazardous solvents and reduction in...3 3 1 7 13 M SMRC Product (gray) Preapplied sealant 2001 3 3 1 7 14 N METSS Product (brown) Preapplied sealant 3 3 1 7 15 O Contro , Plain Rivets 3 3

  2. Lautal as a material for airplane construction

    NASA Technical Reports Server (NTRS)

    Brenner, Paul

    1929-01-01

    Lautal is a refinable aluminum alloy which, unlike duralumin, contains no magnesium. According to the statements of the Lauta Works, lautal contains: aluminum, 94%; copper, 4%; silicon, 2%. The use of lautal as a construction material is discussed in relation to specific weight, production methods, and riveting tests.

  3. 75 FR 15627 - Airworthiness Directives; Turbomeca Astazou XIV B and XIV H Turboshaft Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-30

    ... riveted plugs, were introduced by modification AB 173 in order to improve the vibration characteristics of... vibration characteristics of the turbine wheel. Modification AB 208 brings an improvement to modification AB..., were introduced by modification AB 173 in order to improve the vibration characteristics of the...

  4. Aircraft Structural Maintenance AFSC 458X2

    DTIC Science & Technology

    1993-04-01

    Donald J. Cochran, Inventory Development Specialist, developed the survey instrument; Captain Douglas K. Eads, Occupational Ana- lyst, analyzed the data...0767 INSTALL OR REMOVE PULL-THROUGH BLIND RIVETS 68 M694 REMOVE DAMAGED AREAS USING AVATION SNIPS 68 F256 APPLY AERODYNAMIC SMOOTHING COMPOUNDS 66 0740

  5. Damping Effects in Aerospace Structures

    DTIC Science & Technology

    1979-10-01

    crown and the side webs were cut away. A joint plate with two rivets in single shear restored the continuity of the crown across the cut. The beam... profonde du role a leur faire jouer dans les comnortements dynamiques d’ensesable. 11 s’agit 13 d’un point de vue qui apparaft aujourd’hui encore

  6. Fastener Design Course

    NASA Technical Reports Server (NTRS)

    Barrett, Richard T.

    1997-01-01

    Richard T. Barrett, Senior Aerospace Engineer of NASA Lewis Research Center presents a comprehensive course on fastener design. A recognized expert in the field of fastener technology Mr. Barrett combines lecture, charts, illustrations with real-world experiences. Topics covered include: materials, plantings and coatings, locking methods threads, joint stiffness, rivets, inserts, nut plates, thread lubricants, design criteria, etc. A workbook accompanies the DVD.

  7. 6. PERSPECTIVE VIEW TO SOUTHWEST SHOWING NORTHWEST CORNER OF ASSEMBLY ...

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

    6. PERSPECTIVE VIEW TO SOUTHWEST SHOWING NORTHWEST CORNER OF ASSEMBLY BUILDING WHERE SHOWROOMS (FIRST FLOOR) AND OFFICES (SECOND FLOOR) WERE LOCATED. WEST SIDE OF ASSEMBLY AREA IS TO RIGHT. - Rosie the Riveter National Historical Park, Ford Assembly Plant, 1400 Harbour Way South, Richmond, Contra Costa County, CA

  8. 8. VIEW TO SOUTHEAST FROM NORTHWEST END OF BUILDING, ELEVATION ...

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

    8. VIEW TO SOUTHEAST FROM NORTHWEST END OF BUILDING, ELEVATION OF CENTER BAY WOODEN PRATT ROOF TRUSSES. NOTE VARIABLE DIMENSIONS OF VERTICAL AND DIAGONAL MEMBERS: THICKER TOWARD ENDS AND THINNER TOWARD CENTER. - Rosie the Riveter National Historical Park, Auxiliary Plate Shop, 912 Harbour Way, Richmond, Contra Costa County, CA

  9. 8. VIEW TO EAST SHOWING PORTION OF WEST ELEVATION OF ...

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

    8. VIEW TO EAST SHOWING PORTION OF WEST ELEVATION OF ASSEMBLY AREA. MAIN ASSEMBLY LINE RAN FROM RIGHT TO LEFT ALONG THE FIRST-FLOOR WINDOWS. PARTS STORAGE WAS ON SECOND FLOOR. - Rosie the Riveter National Historical Park, Ford Assembly Plant, 1400 Harbour Way South, Richmond, Contra Costa County, CA

  10. 12. VIEW TO NORTHEAST FROM WITHIN SERVICE OFFICE. THROUGH DOOR ...

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

    12. VIEW TO NORTHEAST FROM WITHIN SERVICE OFFICE. THROUGH DOOR IS LEFT IS DISTRIBUTOR OFFICE; THROUGH DOOR TO RIGHT IS WAITING ROOM AND STAIRS TO FIRST FLOOR. - Rosie the Riveter National Historical Park, Ford Assembly Plant, 1400 Harbour Way South, Richmond, Contra Costa County, CA

  11. 2. GENERAL WAREHOUSE AT SHIPYARD NO. 3, PERSPECTIVE VIEW TO ...

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

    2. GENERAL WAREHOUSE AT SHIPYARD NO. 3, PERSPECTIVE VIEW TO WEST SOUTHWEST, OF FRONT ELEVATION AND NORTH SIDE. LOOKING ACROSS RICHMOND INNER HARBOR FROM NEAR THE FORD ASSEMBLY BUILDING. - Rosie the Riveter National Historical Park, General Warehouse, 1320 Canal Boulevard, Richmond, Contra Costa County, CA

  12. 6. VIEW TO SOUTHEAST ALONG CENTRAL BAY. NOTE TRUSSED SUPPORT ...

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

    6. VIEW TO SOUTHEAST ALONG CENTRAL BAY. NOTE TRUSSED SUPPORT FOR CRANEWAY TRACKS WITH OVERHEAD BRIDGE CRANES IN BACKGROUND. NOTE ALSO SWINGING BOOM CRANES ATTACHED TO COLUMNS. - Rosie the Riveter National Historical Park, Auxiliary Plate Shop, 912 Harbour Way, Richmond, Contra Costa County, CA

  13. 1. VIEW OF GENERAL WAREHOUSE (LEFT) AND MACHINE SHOP (RIGHT) ...

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

    1. VIEW OF GENERAL WAREHOUSE (LEFT) AND MACHINE SHOP (RIGHT) AT SHIPYARD NO. 3, VIEW TO WEST-SOUTHWEST. LOOKING ACROSS RICHMOND INNER HARBOR FROM NEAR THE FORD ASSEMBLY BUILDING. - Rosie the Riveter National Historical Park, General Warehouse, 1320 Canal Boulevard, Richmond, Contra Costa County, CA

  14. 15. Detail showing lower chord pinconnected to vertical member, showing ...

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

    15. Detail showing lower chord pin-connected to vertical member, showing floor beam riveted to extension of vertical member below pin-connection, and showing brackets supporting cantilevered sidewalk. View to southwest. - Selby Avenue Bridge, Spanning Short Line Railways track at Selby Avenue between Hamline & Snelling Avenues, Saint Paul, Ramsey County, MN

  15. The Rosenberg Trial: Uncovering the Layers of History

    ERIC Educational Resources Information Center

    Ragsdale, Bruce A.

    2013-01-01

    The trial of Julius and Ethel Rosenberg on charges of conspiring to spy for the Soviet Union remains one of the defining moments of the Cold War era. The dramatic allegations of stolen atomic secrets and networks of Communist spies riveted the public's attention. The determination of government prosecutors reflected a widely shared belief that the…

  16. 21. VIEW OF INTERFACE BETWEEN THE SOUTHERN TRUSS SECTION'S PINCONNECTED ...

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

    21. VIEW OF INTERFACE BETWEEN THE SOUTHERN TRUSS SECTION'S PIN-CONNECTED EYEBAR LOWER CHORD, AND THE BEGINNING OF THE RIVETED CHANNEL LOWER BRIDGE CHORD USED IN THE CENTRAL AND NORTHERN SECTIONS OF THE BRIDGE. FACING SOUTHEAST. - Coverts Crossing Bridge, Spanning Mahoning River along Township Route 372 (Covert Road), New Castle, Lawrence County, PA

  17. Robotics 101

    ERIC Educational Resources Information Center

    Sultan, Alan

    2011-01-01

    Robots are used in all kinds of industrial settings. They are used to rivet bolts to cars, to move items from one conveyor belt to another, to gather information from other planets, and even to perform some very delicate types of surgery. Anyone who has watched a robot perform its tasks cannot help but be impressed by how it works. This article…

  18. 49 CFR 195.205 - Repair, alteration and reconstruction of aboveground breakout tanks that have been in service.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... approximately atmospheric pressure constructed of carbon and low alloy steel, welded or riveted, and non... service must be capable of withstanding the internal pressure produced by the hazardous liquid to be..., examination, and material requirements of those respective standards. (3) For high pressure tanks built to...

  19. 49 CFR 195.205 - Repair, alteration and reconstruction of aboveground breakout tanks that have been in service.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... approximately atmospheric pressure constructed of carbon and low alloy steel, welded or riveted, and non... service must be capable of withstanding the internal pressure produced by the hazardous liquid to be..., examination, and material requirements of those respective standards. (3) For high pressure tanks built to...

  20. 49 CFR 195.205 - Repair, alteration and reconstruction of aboveground breakout tanks that have been in service.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... approximately atmospheric pressure constructed of carbon and low alloy steel, welded or riveted, and non... service must be capable of withstanding the internal pressure produced by the hazardous liquid to be..., examination, and material requirements of those respective standards. (3) For high pressure tanks built to...

  1. 49 CFR 195.205 - Repair, alteration and reconstruction of aboveground breakout tanks that have been in service.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... approximately atmospheric pressure constructed of carbon and low alloy steel, welded or riveted, and non... service must be capable of withstanding the internal pressure produced by the hazardous liquid to be..., examination, and material requirements of those respective standards. (3) For high pressure tanks built to...

  2. 49 CFR 195.205 - Repair, alteration and reconstruction of aboveground breakout tanks that have been in service.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... approximately atmospheric pressure constructed of carbon and low alloy steel, welded or riveted, and non... service must be capable of withstanding the internal pressure produced by the hazardous liquid to be..., examination, and material requirements of those respective standards. (3) For high pressure tanks built to...

  3. 77 FR 43736 - Airworthiness Directives; Eurocopter Deutschland GmbH Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-26

    ... drive shaft. The proposed actions are intended to detect blind rivets installed in the long tail rotor drive shaft, which could lead to failure of the tail rotor drive shaft and subsequent loss of control of... information identified in this proposed AD, contact American Eurocopter Corporation, 2701 N. Forum...

  4. 20. VIEW TO WEST OF INTERIOR OF CRANEWAY WITH TOW ...

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

    20. VIEW TO WEST OF INTERIOR OF CRANEWAY WITH TOW TRAVELING BRIDGE CRANES (ONE OVERHEAD IN FOREGROUND AND ONE OVERHEAD IN BACKGROUNDS). NOTE WOOD BLOCK PAVING ON THE FLOOR. FIRST FLOOR ASSEMBLY AREA IS THE SPACE IN THE BACKGROUND ON THE RIGHT. - Rosie the Riveter National Historical Park, Ford Assembly Plant, 1400 Harbour Way South, Richmond, Contra Costa County, CA

  5. 11. INTERIOR VIEW TO WEST ALONG SOUTHWEST SIDE OF BUILDING ...

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

    11. INTERIOR VIEW TO WEST ALONG SOUTHWEST SIDE OF BUILDING WITH NORTHWEST END OF BUILDING IN BACKGROUND. NOTE WORK AREAS IN LEAN-TO BAYS ALONG SIDE OF BUILDING. ALSO NOTE TRAVELING BRIDGE CRANES OVERHEAD AND SWINGING BOOM CRANES ATTACHED TO COLUMNS. - Rosie the Riveter National Historical Park, Auxiliary Plate Shop, 912 Harbour Way, Richmond, Contra Costa County, CA

  6. Engineering Drawing II, 6-2. Military Curriculum Project for Vocational and Technical Education.

    ERIC Educational Resources Information Center

    Army Engineer School, Fort Belvoir, VA.

    This military-developed text consists of seven lessons to teach students with basic drafting skills more advanced techniques. Covered in the individual lessons are the following topics: auxiliary views; isometric drawing; screws, bolts, rivets, and welds; detail and assembly practices; intersections and developments; machine drawing; architectural…

  7. 78 FR 38546 - Airworthiness Directives; Bell Helicopter Textron Canada Helicopters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-27

    ..., inspecting the tailboom assembly for a crack, loose rivet, or other damage. This AD was prompted by a stress... cracking. This condition, if not detected, could result in a crack in the tailboom assembly, failure of the... chemically milled tailboom skin ``revealed a possibility of skin cracking due to high stress...

  8. Dear Mr. Kozol. . . . Four African American Women Scholars and the Re-Authoring of Savage Inequalities

    ERIC Educational Resources Information Center

    Farmer-Hinton, Raquel; Lewis, Joi D.; Patton, Lori D.; Rivers, Ishwanzya D.

    2013-01-01

    Background: In 1991, Savage Inequalities quickly became the most riveting assessment of the inequalities in U.S. public schools. When Kozol visited East St. Louis for his book, the authors of this paper lived and attended schools there. As Kozol's readers in their respective graduate and undergraduate classes, the authors found it difficult to…

  9. 11. View showing detail of truss tower. The vertical, or ...

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

    11. View showing detail of truss tower. The vertical, or compression, members of the bridge are formed from two channel beams riveted together with lacing bars. The diagonal or tension members, are die-forged eyebars. - Center Street Swing Bridge, Southwest of Public Square, Cleveland, Cuyahoga County, OH

  10. Celebrating Excellence: Learning and Teaching in Adult Higher Education. National Conference on Alternative and External Degree Programs for Adults (15th, Columbus, Ohio, October 5-7, 1995).

    ERIC Educational Resources Information Center

    Alliance, an Association for Alternative Degree Programs.

    These 23 presentations are organized in five categories: diversity, assessment, distance education, learning, and teaching. Five papers on diversity include the following: "From Rosie the Riveter to Comparable Worth: The Infusion of Gender and Women's Issues into an Interdisciplinary Curriculum for Working Adults" (Linda L. Hulbert, Theodore A.…

  11. Teen Cyberbullying Investigated: Where Do Your Rights End and Consequences Begin?

    ERIC Educational Resources Information Center

    Jacobs, Thomas A.

    2010-01-01

    The Internet age has led to a different kind of teen bullying: cyberbullying. What is cyberbullying and what can teens do about it? In "Teen Cyberbullying Investigated," Judge Tom Jacobs presents a powerful collection of landmark court cases involving teens and charges of cyberbullying and cyberharassment. This riveting, informative guide will…

  12. 49 CFR 230.20 - Alteration and repair report for steam locomotive boilers.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... boilers. 230.20 Section 230.20 Transportation Other Regulations Relating to Transportation (Continued... boilers. (a) Alterations. When an alteration is made to a steam locomotive boiler, the steam locomotive... maintained for the life of the boiler. (See appendix B of this part.) (b) Welded and riveted repairs...

  13. 49 CFR 230.20 - Alteration and repair report for steam locomotive boilers.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... boilers. 230.20 Section 230.20 Transportation Other Regulations Relating to Transportation (Continued... boilers. (a) Alterations. When an alteration is made to a steam locomotive boiler, the steam locomotive... maintained for the life of the boiler. (See appendix B of this part.) (b) Welded and riveted repairs...

  14. 49 CFR 230.20 - Alteration and repair report for steam locomotive boilers.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... boilers. 230.20 Section 230.20 Transportation Other Regulations Relating to Transportation (Continued... boilers. (a) Alterations. When an alteration is made to a steam locomotive boiler, the steam locomotive... maintained for the life of the boiler. (See appendix B of this part.) (b) Welded and riveted repairs...

  15. 49 CFR 230.20 - Alteration and repair report for steam locomotive boilers.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... boilers. 230.20 Section 230.20 Transportation Other Regulations Relating to Transportation (Continued... boilers. (a) Alterations. When an alteration is made to a steam locomotive boiler, the steam locomotive... maintained for the life of the boiler. (See appendix B of this part.) (b) Welded and riveted repairs...

  16. 49 CFR 230.20 - Alteration and repair report for steam locomotive boilers.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... boilers. 230.20 Section 230.20 Transportation Other Regulations Relating to Transportation (Continued... boilers. (a) Alterations. When an alteration is made to a steam locomotive boiler, the steam locomotive... maintained for the life of the boiler. (See appendix B of this part.) (b) Welded and riveted repairs...

  17. Structural Stability Assessment of the High Frequency Antenna for Use on the Buccaneer CubeSat in Low Earth Orbit

    DTIC Science & Technology

    2014-05-01

    rivets will not be used for the antenna as shown at the end of the tape in Figure 2. The antenna will be in a stable equilibrium position once it is...remained stationary the tape attachment point would behave like a pinned joint and crease as it is unable to transfer bending moment. Rotational

  18. Preprocessing of Edge of Light images: towards a quantitative evaluation

    NASA Astrophysics Data System (ADS)

    Liu, Zheng; Forsyth, David S.; Marincak, Anton

    2003-08-01

    A computer vision inspection system, named Edge of Light TM (EOL), was invented and developed at the Institute for Aerospace Research of the National Research Council Canada. One application of interest is the detection and quantitative measurement of "pillowing" caused by corrosion in the faying surfaces of aircraft fuselage joints. To quantify the hidden corrosion, one approach is to relate the average corrosion of a region to the peak-to-peak amplitude between two diagonally adjacent rivet centers. This raises the requirement for automatically locating the rivet centers. The first step to achieve this is the rivet edge detection. In this study, gradient-based edge detection, local energy based feature extraction, and an adaptive threshold method were employed to identify the edge of rivets, which facilitated the first step in the EOL quantification procedure. Furthermore, the brightness profile is processed by the derivative operation, which locates the pillowing along the scanning direction. The derivative curves present an estimation of the inspected surface.

  19. Comparison of the biomechanics and histology of two soft-tissue fixators composed of bioabsorbable copolymers.

    PubMed

    Powers, D L; Sonawala, M; Woolf, S K; An, Y H; Hawkins, R; Pietrzak, W S

    2001-01-01

    The purpose of this study was to assess the dynamic in vitro and in vivo characteristics of two different bioabsorbable copolymer soft-tissue fixation devices and to determine their efficacy in reattaching soft tissue to bone. Suretac fixators (Smith & Nephew/Acufex MicroSurgical Inc., Northwood, MA), made of polyglyconate (2:1 glycolic acid:trimethylene carbonate), and Pop Rivets (Arthrotek, Warsaw, IN), made of LactoSorb (82% poly L-lactic acid, 18% polyglycolic acid), were anchored into synthetic bone, and their pull-out strengths were evaluated. The devices were also evaluated with the use of an in vivo goat model in which the medial collateral ligament (MCL) was elevated from the tibia and directly reattached. In the in vitro biomechanical study, the Suretac fixators had negligible strength remaining by four weeks, whereas the Pop Rivets retained 50% of their strength at 4 weeks, 20% at 8 weeks, and negligible strength at 12 weeks. The in vivo strength of MCL repairs affected by each implant was not statistically different at any of the time points. Histologically, both implants were absorbed by 52 weeks, and there was no appreciable adverse tissue response. In conclusion, both copolymer fixators were found to be biocompatible. The Pop Rivet fixators demonstrated in vivo performance comparable to the Suretac fixators, although the Pop Rivets retained strength longer in vitro. Our results suggest that both devices provide adequate strength of fixation before degrading to allow the healing soft tissues to reach or surpass their native strength.

  20. 49 CFR 179.200-22 - Test of tanks.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... evidence of distress. All rivets and closures, except safety relief valves or safety vents, shall be in...-lined tanks shall be tested before rubber lining is applied. (d) Caulking of welded joints to stop leaks developed during the foregoing tests is prohibited. Repairs in welded joints shall be made as prescribed...

  1. Sculpture, Metallic Formations II, Art Education: 6683.12b.

    ERIC Educational Resources Information Center

    Dubocq, Edward R.

    An exploratory course in the creation of shapes using a variety of metals and techniques is described in this guide for quinmester elective course for grades 7-12. Students cut, form, weld, rivet, cast and finish such metals as steel, copper, aluminum, brass, pewter, and bronze. They develop a working knowledge of the various tools and processes,…

  2. 5. PERSPECTIVE VIEW TO EAST SHOWING NORTHWEST END AND SOUTHWEST ...

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

    5. PERSPECTIVE VIEW TO EAST SHOWING NORTHWEST END AND SOUTHWEST SIDE OF BUILDING. (NOTE THAT RIGHT PORTION OF PHOTOGRAPH WAS FOGGED DUE TO BELLOWS LEAK). - Rosie the Riveter National Historical Park, Auxiliary Plate Shop, 912 Harbour Way, Richmond, Contra Costa County, CA

  3. Evaluating Courses of Actions at the Strategic Planning Level

    DTIC Science & Technology

    2013-03-01

    critical airborne theater assets such as AWACS, Rivet Joint, and JSTARS (AFDD-2-1.1 1998). This measurement will quantify the level of covering...Decisions. New York: Springer -Verlag, 1988. Riaz, Muhammad Sharjeel. Value Focused Thinking for Nation Building in Afghanistan a Regional Perspective

  4. Time Critical Targeting Concept of Operations (CONOPS) Interactions

    DTIC Science & Technology

    2011-05-01

    video.  1 Low Earth Orbit (LEO) SBR constellation overhead 40-80% of time with SAR and GMTI.  1 Rivet Joint orbit or Signals Intelligence (SIGINT...1217, Springer -Verlag 1997, 203-208. Keithley, H, “Space Based Radar Utility Analysis”, DSC FY02 Study Task 1 (DSC 02-1), Volume III Tracking

  5. A Numerical Modeling Framework for Cohesive Sediment Transport Driven by Waves and Tidal Currents

    DTIC Science & Technology

    2012-09-30

    are directly relevant to RIVET I & II where the seabed is mainly sandy or mixed sand-mud environments. 5 (a1) (a2) (b1...Direct simulation of a turbulent oscillating boundary layer. In Turbulent Shear Flows 6 (ed. J. C. Andre), pp. 417–440, Springer . Traykovski, P

  6. 49 CFR 236.743 - Dog, swing.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Dog, swing. 236.743 Section 236.743 Transportation... OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Definitions § 236.743 Dog, swing. A locking dog mounted in such a manner that it is free to rotate on a trunnion which is riveted to a...

  7. 78 FR 22435 - Airworthiness Directives; The Boeing Company Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-16

    ... become large and cause the floor beams to become severed and result in rapid decompression or reduced... structural design details, or globally. Global fatigue damage is general degradation of large areas of... occurs in a large structural element such as a single rivet line of a lap splice joining two large...

  8. An alternative fabrication method of the dart thrower's motion orthosis (also known as the dart orthosis).

    PubMed

    Schwartz, Deborah A

    2016-01-01

    To allow safe early wrist motion after wrist injury, this author has modified an earlier version of a dart thrower's motion orthotic device using material that is currently available on the market and an inexpensive paper fastener as the rivet. - KristinValdes, OTD, OT, CHT, Practice Forum Editor.

  9. VIEW TO SOUTHEAST FROM NORTHWEST CORNER OF BASING NO. 4 ...

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

    VIEW TO SOUTHEAST FROM NORTHWEST CORNER OF BASING NO. 4 (SECOND BASING FROM THE EAST) SHOWING CRANEWAY AND GALLERY BETWEEN BASINS NO. 4 AND 5. GENERAL WAREHOUSE IS IN BACKGROUND - Rosie the Riveter National Historical Park, Graving Docks, Shipyard No. 3, Richmond, Contra Costa County, CA

  10. YARD NO. 3 BASINS (GRAVING DOCKS), VIEW TO EASTNORTHEAST AT ...

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

    YARD NO. 3 BASINS (GRAVING DOCKS), VIEW TO EAST-NORTHEAST AT THE SOUTH END OF THE CRANEWAY AND GALLERY BETWEEN BASINS NO. 1 AND 2, LOOKING ACROSS SOUTH END OF BASIN NO. 1 (THE WESTERN-MOST BASIN) - Rosie the Riveter National Historical Park, Graving Docks, Shipyard No. 3, Richmond, Contra Costa County, CA

  11. 6. VIEW OF THE EASTERN BRIDGE ELEVATION, SHOWING CENTRAL PIER ...

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

    6. VIEW OF THE EASTERN BRIDGE ELEVATION, SHOWING CENTRAL PIER AND ASSOCIATED SUPERSTRUCTURE, AND CANTILEVERED NORTHERN TRUSS SECTION. NOTE THE JOIN BETWEEN EYE-BAR (LEFT) AND RIVETED CHANNEL (RIGHT) LOWER BRIDGE CHORDS AT CENTER LEFT OF PHOTOGRAPH. FACING NORTH. - Coverts Crossing Bridge, Spanning Mahoning River along Township Route 372 (Covert Road), New Castle, Lawrence County, PA

  12. On the Strength of Box Type Fuselages

    NASA Technical Reports Server (NTRS)

    Mathar, J

    1929-01-01

    The present investigation relates to a box-type fuselage with sides consisting of thin smooth sheet metal, stiffened by longitudinal members riveted to the flanged channel-section bulkheads or transverse frames and to the semicircular corrugated corner stiffenings. The results obtained in this particular case can be applied to a great number of similar structures.

  13. 49 CFR 236.743 - Dog, swing.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Dog, swing. 236.743 Section 236.743 Transportation... OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Definitions § 236.743 Dog, swing. A locking dog mounted in such a manner that it is free to rotate on a trunnion which is riveted to a...

  14. 49 CFR 236.743 - Dog, swing.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Dog, swing. 236.743 Section 236.743 Transportation... OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Definitions § 236.743 Dog, swing. A locking dog mounted in such a manner that it is free to rotate on a trunnion which is riveted to a...

  15. 49 CFR 236.743 - Dog, swing.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Dog, swing. 236.743 Section 236.743 Transportation... OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Definitions § 236.743 Dog, swing. A locking dog mounted in such a manner that it is free to rotate on a trunnion which is riveted to a...

  16. 49 CFR 236.743 - Dog, swing.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Dog, swing. 236.743 Section 236.743 Transportation... OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Definitions § 236.743 Dog, swing. A locking dog mounted in such a manner that it is free to rotate on a trunnion which is riveted to a...

  17. The Cuban Missile Crisis: Considering Its Place in Cold War History. Teacher's Resource Book [and Student Text]. Public Policy Debate in the Classroom. Choices for the 21st Century Education Project. 4th Edition.

    ERIC Educational Resources Information Center

    Soukup, Nancy, Ed.

    Like no other region on the globe, the Caribbean Basin has served as a testing ground for U.S. foreign policy. Of all the countries in the region, Cuba has been the scene of many of the United States' most riveting foreign policy dramas. The teacher resource book and student text probe the complex, often troubled, relationship between the United…

  18. Literature Review and Preliminary Studies of Fretting and Fretting Fatigue Including Special Applications to Aircraft Joints.

    DTIC Science & Technology

    1994-04-01

    interfay sealant appeared to be porous. There was a small fatigue reduction. Hot bonded joints ( hot cured interfay) had no cracking at rivet holes. A...Base, Ohio,1973, 11 pp. 1 05 F. E. Kiddie , Fatigue behavior of bolted joints in RR58 aluminum alloy with and without interfay sealant, Procurement

  19. 17. VIEW TO EAST SHOWING ONE OF THE OPENINGS IN ...

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

    17. VIEW TO EAST SHOWING ONE OF THE OPENINGS IN THE SECOND FLOOR EAST WALL THROUGH WHICH A CONVEYOR ONCE PASSED FOR MOVING BODY PANELS TO AND FROM THE SECOND FLOOR. - Rosie the Riveter National Historical Park, Ford Assembly Plant, 1400 Harbour Way South, Richmond, Contra Costa County, CA

  20. Low-Hazardous Air Pollutant (HAP)/Volatile Organic Compound (VOC) - Compliant Resins for Military Applications

    DTIC Science & Technology

    2012-07-01

    174 Figure 103. MCM rudder 2— leading edge near caul plate...175 Figure 104. MCM rudder 2— leading edge away from caul plate. .............................................176 Figure 105. MCM rudder 2—shear...pieces were riveted together. Unfortunately, this leads to high corrosion rates of the hood, requiring a lot of maintenance work (figure 9). Sheet

  1. 18. DETAIL, L0 JOINT AND BEARING SEAT AT WEST ABUTMENT, ...

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

    18. DETAIL, L0 JOINT AND BEARING SEAT AT WEST ABUTMENT, FROM NORTH, SHOWING RIVETED CONNECTION OF BOTTOM CHORD AND END POST AT JOINT, AND FIXED SHOE - Glendale Road Bridge, Spanning Deep Creek Lake on Glendale Road, McHenry, Garrett County, MD

  2. 46 CFR 59.10-30 - Seal welding.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Seal welding. 59.10-30 Section 59.10-30 Shipping COAST... VESSELS AND APPURTENANCES Welding Repairs to Boilers and Pressure Vessels in -Service § 59.10-30 Seal welding. Where leaks occur in riveted joints or connections, they shall be carefully investigated...

  3. 46 CFR 189.50-1 - Inspection and testing required when making alterations, repairs, or other such operations...

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ..., repairs, or other such operations involving riveting, welding, burning, or like fire-producing actions..., welding, burning, or like fire-producing actions. (a) The provisions of “Standard for the Control of Gas..., burning, welding, or like fire-producing actions shall be made: (1) Within or on the boundaries of...

  4. 16 CFR Appendix to Part 23 - Exemptions Recognized in the Assay for Quality of Gold Alloy, Gold Filled, Gold Overlay, Rolled...

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Quality of Gold Alloy, Gold Filled, Gold Overlay, Rolled Gold Plate, Silver, and Platinum Industry..., Silver, and Platinum Industry Products (a) Exemptions recognized in the industry and not to be considered... in any assay for quality of a silver industry product include screws, rivets, springs, spring...

  5. 16 CFR Appendix to Part 23 - Exemptions Recognized in the Assay for Quality of Gold Alloy, Gold Filled, Gold Overlay, Rolled...

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... Quality of Gold Alloy, Gold Filled, Gold Overlay, Rolled Gold Plate, Silver, and Platinum Industry..., Silver, and Platinum Industry Products (a) Exemptions recognized in the industry and not to be considered... in any assay for quality of a silver industry product include screws, rivets, springs, spring...

  6. 46 CFR 71.60-1 - Inspection and testing required when making alterations, repairs, or other such operations...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... undertaken with safety, no alterations, repairs, or other such operations involving riveting, welding... boundaries of fuel tanks; or, (3) To pipe lines, heating coils, pumps, fittings, or other appurtenances... the inspection indicated that such operations can be undertaken with safety, a certificate...

  7. 46 CFR 71.60-1 - Inspection and testing required when making alterations, repairs, or other such operations...

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... undertaken with safety, no alterations, repairs, or other such operations involving riveting, welding... boundaries of fuel tanks; or, (3) To pipe lines, heating coils, pumps, fittings, or other appurtenances... the inspection indicated that such operations can be undertaken with safety, a certificate...

  8. 46 CFR 189.50-1 - Inspection and testing required when making alterations, repairs, or other such operations...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... can be undertaken with safety, no alterations, repairs, or other such operations involving riveting... liquids or within spaces adjacent to such tanks; or, (5) To pipelines, heat coils, pumps, fittings, or... inspection. If the inspection indicates that such operations can be undertaken with safety, a...

  9. 46 CFR 35.01-1 - Inspection and testing required when making alterations, repairs, or other such operations...

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... safety, no alterations, repairs, or other such operations involving riveting, welding, burning, or like..., pumps, fittings, or other appurtenances connected to such cargo or fuel tanks. (c) Such inspections... safety, a certificate setting forth the fact in writing and qualified as may be required, shall be...

  10. 46 CFR 71.60-1 - Inspection and testing required when making alterations, repairs, or other such operations...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... undertaken with safety, no alterations, repairs, or other such operations involving riveting, welding... boundaries of fuel tanks; or, (3) To pipe lines, heating coils, pumps, fittings, or other appurtenances... the inspection indicated that such operations can be undertaken with safety, a certificate...

  11. 46 CFR 167.30-10 - Special operating requirements.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... can be undertaken with safety, no alterations, repairs, or other such operations involving riveting..., (3) Within or on the boundaries of fuel tanks; or, (4) To pipe lines, heating coils, pumps, fittings... inspection. If the inspection indicates that such operations can be undertaken with safety, a...

  12. 16. VIEW TO NORTHEAST OF SECONDFLOOR ASSEMBLY AREA FROM NEAR ...

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

    16. VIEW TO NORTHEAST OF SECOND-FLOOR ASSEMBLY AREA FROM NEAR SOUTHWEST WEST. NOTE DIFFERENCE IN ROOF STRUCTURE BETWEEN SAWTOOTH SKYLIGHTS OVER MOST OF THE SECOND FLOOR (RIGHT) AND THE PORTION OF THE ROOF RUNNING ALONG THE WEST EDGE OF THE BUILDING (LEFT). - Rosie the Riveter National Historical Park, Ford Assembly Plant, 1400 Harbour Way South, Richmond, Contra Costa County, CA

  13. Aviation Maintenance Safety Articles, January/February 1990

    DTIC Science & Technology

    1990-02-01

    Superintendent of Docrerts i. S Gover ’ Tart 0 Printing Office Washington DC 20402 Second Class postage pad at Ma’- Pa I. WE, POSTMASTER Send address... Cherry Max rivet. After the operator A review of NAVMATSO records indicates that pulled the trigger and while the gun was cycling the Navy and Marine

  14. Survey and Testing of Archaeological Resources at Clinton Lake, Kansas, 1978-1979.

    DTIC Science & Technology

    1980-08-01

    By 11,500 B.P., mixed prairie and deciduous forest with .-.. ironwood and hazelnut replaced the spruce forest. Because of further climatic...dewberries, hazelnuts , pokeweed, grapes, sorrels and several others (Schmits 1976). 0 , . - *- . 5i Ii PLATE 3 The eastward view of the Wakarusa Rivet

  15. 49 CFR 238.230 - Safety appliances-new equipment.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... part 231 of this chapter to be attached by a mechanical fastener (i.e., bolts, rivets, or screws.../2 inch diameter bolts that would be required for each attachment; (iii) Except for any access... not considered part of the car body under paragraph (b)(1) of this section; (iii) A detailed...

  16. 49 CFR 238.230 - Safety appliances-new equipment.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... part 231 of this chapter to be attached by a mechanical fastener (i.e., bolts, rivets, or screws.../2 inch diameter bolts that would be required for each attachment; (iii) Except for any access... not considered part of the car body under paragraph (b)(1) of this section; (iii) A detailed...

  17. 49 CFR 238.230 - Safety appliances-new equipment.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... part 231 of this chapter to be attached by a mechanical fastener (i.e., bolts, rivets, or screws.../2 inch diameter bolts that would be required for each attachment; (iii) Except for any access... not considered part of the car body under paragraph (b)(1) of this section; (iii) A detailed...

  18. 49 CFR 238.230 - Safety appliances-new equipment.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... part 231 of this chapter to be attached by a mechanical fastener (i.e., bolts, rivets, or screws.../2 inch diameter bolts that would be required for each attachment; (iii) Except for any access... not considered part of the car body under paragraph (b)(1) of this section; (iii) A detailed...

  19. 49 CFR 238.230 - Safety appliances-new equipment.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... part 231 of this chapter to be attached by a mechanical fastener (i.e., bolts, rivets, or screws.../2 inch diameter bolts that would be required for each attachment; (iii) Except for any access... not considered part of the car body under paragraph (b)(1) of this section; (iii) A detailed...

  20. 10. View northwest Typical panel detail (south chord) of variable ...

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

    10. View northwest Typical panel detail (south chord) of variable section girder showing riveted connections, angle stiffeners for girder web, and nuts securing wind bracing rods. - Walpole-Westminster Bridge, Spanning Connecticut River between Walpole, NH & Westminster, VT, Walpole, Cheshire County, NH

  1. 9. VIEW TO SOUTH SHOWING ENTRANCES TO BUILDING AT NORTHEAST ...

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

    9. VIEW TO SOUTH SHOWING ENTRANCES TO BUILDING AT NORTHEAST CORNER. DOORS TO LEFT WERE FOR INTERIOR RAILROAD SPUR. ROLL-UP GARAGE DOOR TO RIGHT HAS REPLACED ORIGINAL PEDESTRIAN DOORS WHERE HOURLY SHIP WORKERS REPORTED TO WORK. - Rosie the Riveter National Historical Park, Ford Assembly Plant, 1400 Harbour Way South, Richmond, Contra Costa County, CA

  2. 12. Detail of west side of southwest portal showing the ...

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

    12. Detail of west side of southwest portal showing the latticed diagonal brace and the hip vertical, pin-connected to the latticed inclined end post directly beneath the riveted connection with the portal bracing. - Post Road Bridge, State Route 7-A, Havre de Grace, Harford County, MD

  3. 13. Detail of west side of southwest portal showing the ...

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

    13. Detail of west side of southwest portal showing the latticed top chord rivet-connected to the latticed inclined end post and the portal strut; also shown is the webbed portal bracing and the top lateral bracing with the pin connection of the hip vertical and the diagonal. - Post Road Bridge, State Route 7-A, Havre de Grace, Harford County, MD

  4. 26 CFR 48.4061(a)-1 - Imposition of tax; exclusion for light-duty trucks, etc.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ..., bolting, riveting, or other means) machinery or equipment to perform a construction, manufacturing...), equipment or machinery installed on a taxable chassis or body is considered to be an integral part of the taxable chassis or body if the machinery or equipment contributes toward the highway...

  5. 26 CFR 48.4061(a)-1 - Imposition of tax; exclusion for light-duty trucks, etc.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ..., bolting, riveting, or other means) machinery or equipment to perform a construction, manufacturing...), equipment or machinery installed on a taxable chassis or body is considered to be an integral part of the taxable chassis or body if the machinery or equipment contributes toward the highway...

  6. 26 CFR 48.4061(a)-1 - Imposition of tax; exclusion for light-duty trucks, etc.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ..., bolting, riveting, or other means) machinery or equipment to perform a construction, manufacturing...), equipment or machinery installed on a taxable chassis or body is considered to be an integral part of the taxable chassis or body if the machinery or equipment contributes toward the highway...

  7. 18. VIEW TO EAST, DETAIL OF OPENING THROUGH THE SECOND ...

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

    18. VIEW TO EAST, DETAIL OF OPENING THROUGH THE SECOND FLOOR EAST WALL SHOWING CONVEYOR FOR MOVING MATERIAL TO THE SECOND FLOOR. (NOTE: THIS IS NOT AN ORIGINAL CONVEYOR FOR MOVING BODY PARTS). - Rosie the Riveter National Historical Park, Ford Assembly Plant, 1400 Harbour Way South, Richmond, Contra Costa County, CA

  8. The Adult Learner: Some Things We Know

    ERIC Educational Resources Information Center

    Fogarty, Robin J.; Pete, Brian M.

    2007-01-01

    This book addresses the "warrior" who rises to the challenge of teaching the adult learner. The discussion is designed as a catalyst for dialogue about the adult learner and to uncover the complexities of teaching this rare and riveting species. This book is organized around three interlocking themes: some things we know about the adult learner;…

  9. 29 CFR 1917.152 - Welding, cutting and heating (hot work) 12 (See also § 1917.2, definition of Hazardous cargo...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... atmosphere and determined that it is not hazardous. (c) Fire protection. (1) To the extent possible, hot work shall be performed in designated locations that are free of fire hazards. (2) When hot work must be... riveting, welding, flame cutting or other fire or spark-producing operation. (b) Hot work in...

  10. 29 CFR 1917.152 - Welding, cutting and heating (hot work) 12 (See also § 1917.2, definition of Hazardous cargo...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... atmosphere and determined that it is not hazardous. (c) Fire protection. (1) To the extent possible, hot work shall be performed in designated locations that are free of fire hazards. (2) When hot work must be... riveting, welding, flame cutting or other fire or spark-producing operation. (b) Hot work in...

  11. The design of repairable advanced composite structures

    NASA Technical Reports Server (NTRS)

    Hart-Smith, L. J.

    1985-01-01

    This paper addresses the repair of advanced composite structures by mechanical fasteners or by adhesive bonding. It is shown that many of today's composite designs are unreasonably difficult to repair. Conversely, the knowledge to design repairable structures is already available, if only it is applied during the initial design stage. Bolted or riveted repairs require only the avoidance of extremely orthotropic composite fiber patterns; those near the quasi-isotropic layup are the most suitable. Mildly orthotropic fiber patterns are appropriate for structures in which there is a dominant load direction. Thick composite structures are shown to require bolted or riveted repairs while thin structures favor adhesively bonded permanent repairs, although provisions can be easily made for temporary mechanical repairs. The reasons why integrally stiffened cocured composite designs are usually impractical to repair are explained and alternative repairable design concepts are presented.

  12. Tetraploid Wheat Landraces in the Mediterranean Basin: Taxonomy, Evolution and Genetic Diversity

    PubMed Central

    Oliveira, Hugo R.; Campana, Michael G.; Jones, Huw; Hunt, Harriet V.; Leigh, Fiona; Redhouse, David I.; Lister, Diane L.; Jones, Martin K.

    2012-01-01

    The geographic distribution of genetic diversity and the population structure of tetraploid wheat landraces in the Mediterranean basin has received relatively little attention. This is complicated by the lack of consensus concerning the taxonomy of tetraploid wheats and by unresolved questions regarding the domestication and spread of naked wheats. These knowledge gaps hinder crop diversity conservation efforts and plant breeding programmes. We investigated genetic diversity and population structure in tetraploid wheats (wild emmer, emmer, rivet and durum) using nuclear and chloroplast simple sequence repeats, functional variations and insertion site-based polymorphisms. Emmer and wild emmer constitute a genetically distinct population from durum and rivet, the latter seeming to share a common gene pool. Our population structure and genetic diversity data suggest a dynamic history of introduction and extinction of genotypes in the Mediterranean fields. PMID:22615891

  13. Finite Element Simulation of Plastic Joining Processes of Steel and Aluminum Alloy Sheets

    SciTech Connect

    Mori, K.; Abe, Y.; Kato, T.

    2007-05-17

    Various high tensile strength steel sheets and an aluminum alloy sheet were joined with a self-piercing rivet. It is not easy to weld the aluminum alloy sheet and high tensile strength sheets by means of conventional resistance welding because of very different melting points. To obtain optimum joining conditions, joining defects were categorized into separation of the sheets and an inner fracture. The joining range of ultra high tensile strength steel and aluminum alloy sheets was extended by means of dies optimized by finite element simulation. The joint strength is greatly influenced by not only the strength of the sheets and rivets but also the ratio of the thickness of the lower sheet to the total thickness. In addition, mechanical clinching of high strength steel and aluminum alloy sheets was simulated.

  14. Finite Element Simulation of Plastic Joining Processes of Steel and Aluminum Alloy Sheets

    NASA Astrophysics Data System (ADS)

    Mori, K.; Abe, Y.; Kato, T.

    2007-05-01

    Various high tensile strength steel sheets and an aluminum alloy sheet were joined with a self-piercing rivet. It is not easy to weld the aluminum alloy sheet and high tensile strength sheets by means of conventional resistance welding because of very different melting points. To obtain optimum joining conditions, joining defects were categorized into separation of the sheets and an inner fracture. The joining range of ultra high tensile strength steel and aluminum alloy sheets was extended by means of dies optimized by finite element simulation. The joint strength is greatly influenced by not only the strength of the sheets and rivets but also the ratio of the thickness of the lower sheet to the total thickness. In addition, mechanical clinching of high strength steel and aluminum alloy sheets was simulated.

  15. A laboratory study of fracture in the presence of lap splice multiple site damage

    NASA Astrophysics Data System (ADS)

    Mayville, Ronald A.; Warren, Thomas J.

    Flat coupons were tested in the laboratory to determine a fracture criterion for link-up of fuselage lap splice multiple site damage at adjacent rivet holes. Experiments were performed on 0.040 inch (1 mm) thick 2024-T3 clad aluminum sheet. Continuous and riveted lap splice coupons were tested with simulated uniform (equal crack lengths) and nonuniform MSD, and the effects of notch sharpness were also studied. A net section stress criterion was found to provide excellent predictions of fracture for uniform MSD and uniform stress distributions. This same criterion provides conservative predictions for nonuniform MSD in uniform stress fields. An overload/cyclic stress experiment was also conducted to explore the pressurized proof test scenario of ensuring structural integrity.

  16. Mechanical fastening solution with a sealing undercut which ensures a uniform force transmission

    NASA Astrophysics Data System (ADS)

    Krugmann, J.; Moritzer, E.

    2014-05-01

    Whereas metal rivet connections are well-researched and are used especially with lightweight structures [1], plastic rivet connections are still in need of further research. The fastening solution presented here represents an alternative to existing connections. Through the direct molding-on of a boss with an optimized geometry, a mechanical connection is created with a uniform sealing undercut over the entire circumference. The method of direct screwing assumes significant importance in the development of the new fastening solution. It is only the introduction of the threaded screw that creates the axial tension for the compression of the boss, and thus, together with the necessary preload force, secures the connection. The characteristic features of the fastening element are one-side accessibility (blind joint), uniform force transmission and simultaneous sealing of the connection.

  17. Fatigue growth of multiple-cracks near a row of fastener-holes in a fuselage lap-joint

    NASA Astrophysics Data System (ADS)

    Park, J. H.; Atluri, S. N.

    1993-12-01

    The fatigue growth of multiple cracks, of arbitrary lengths, emanating from a row of fastener holes in a bonded, riveted, lap joint in a pressurized aircraft fuselage is studied. The effects of residual stresses due to a rivet misfit, and of plastic deformation near the hole, are included. A Schwartz-Neumann alternating method which uses the analytical solution for a row of multiple colinear cracks in an infinite sheet (the crack-faces being subject to arbitrary tractions), is developed to analyze this MSD problem on a personal computer. It is found that for a range of crack lengths, a phenomena wherein the shorter cracks may grow faster than longer cracks may exist.

  18. Arthroscopy for shoulder instability and a technique for arthroscopic repair.

    PubMed

    Wiley, A M

    1988-01-01

    At this time the principal role of the arthroscope in the management of dislocating shoulder seems to be the identification of the intra-articular pathology. The findings should enable a surgeon to carry out an appropriate open repair, and the results of such surgery are excellent. Is there a place for arthroscopic repair? Some patients sometimes request it; others have had a failed open repair, or wish to avoid a scar. The author has devised a removable "Rivet," which fixes a loose labrum and the inferior glenohumeral ligament back on to a roughened glenoid margin. Use of this technique avoids some of the hazards that occur with implanting a staple or similar device in the joint. The "Rivet" is removed after 4-6 weeks. Ten patients have been so treated, with a follow-up of 6 months to 2 years. There was one failure, with a return of dislocation.

  19. Analytical and experimental investigation of fatigue in lap joints

    NASA Astrophysics Data System (ADS)

    Swenson, Daniel V.; Chih-Chien, Chia; Derber, Thomas G.

    A finite element model is presented that can simulate crack growth in layered structures such as lap joints. The layers can be joined either by rivets or adhesives. The crack is represented discretely in the mesh, and automatic remeshing is performed as the crack grows. Because of the connections between the layers, load is transferred to the uncracked layer as the crack grows. This reduces the stress intensity and slows the crack growth rate. The model is used to analyze tests performed on a section of a wing spanwise lap joint. The crack was initiated at a rivet and grown under constant amplitude cyclic loads. Both experimentally observed crack growth rates and the analysis show the retardation that occurs as a result of load transfer between layers. A good correlation is obtained between predicted and observed crack growth rates for the fullly developed through-thickness crack.

  20. The fretting damage and effect of temperature in typical joint of aircraft construction

    NASA Astrophysics Data System (ADS)

    Tian, T. Z.

    The fatigue test results and the fatigue fracture for three types of joints, i.e., bolted joints, set-head rivet joints and countersunk rivet joints of the aluminum alloy, have been studied on the basis of more than 200 joints test at both elevated temperature and room temperature. It is revealed that the cracks initiated in the places where fretting had taken place and led to the failure of fretting fatigue. Different types of joints cause different modes of transmitting loads so that the places of cracks changed, which result in difference of fatigue strength. In this paper, the effect of fretting damage on fatigue strength and the effect of elevated temperature on fatigue strength and fracture appearance are also presented.

  1. The characterization of widespread fatigue damage in fuselage structure

    NASA Technical Reports Server (NTRS)

    Piascik, Robert S.; Willard, Scott A.; Miller, Matthew

    1994-01-01

    The characteristics of widespread fatigue damage (WSFD) in fuselage riveted structure were established by detailed nondestructive and destructive examinations of fatigue damage contained in a full size fuselage test article. The objectives of this were to establish an experimental data base for validating emerging WSFD analytical prediction methodology and to identify first order effects that contribute to fatigue crack initiation and growth. Detailed examinations were performed on a test panel containing four bays of a riveted lap splice joint. The panel was removed from a full scale fuselage test article after receiving 60,000 full pressurization cycles. The results of in situ examinations document the progression of fuselage skin fatigue crack growth through crack linkup. Detailed tear down examinations and fractography of the lap splice joint region revealed fatigue crack initiation sites, crack morphology, and crack linkup geometry. From this large data base, distributions of crack size and locations are presented and discussions of operative damage mechanisms are offered.

  2. Heuristic Enhancement of Magneto-Optical Images for NDE

    NASA Astrophysics Data System (ADS)

    Cacciola, Matteo; Megali, Giuseppe; Pellicanò, Diego; Calcagno, Salvatore; Versaci, Mario; Morabito, FrancescoCarlo

    2010-12-01

    The quality of measurements in nondestructive testing and evaluation plays a key role in assessing the reliability of different inspection techniques. Each different technique, like the magneto-optic imaging here treated, is affected by some special types of noise which are related to the specific device used for their acquisition. Therefore, the design of even more accurate image processing is often required by relevant applications, for instance, in implementing integrated solutions for flaw detection and characterization. The aim of this paper is to propose a preprocessing procedure based on independent component analysis (ICA) to ease the detection of rivets and/or flaws in the specimens under test. A comparison of the proposed approach with some other advanced image processing methodologies used for denoising magneto-optic images (MOIs) is carried out, in order to show advantages and weakness of ICA in improving the accuracy and performance of the rivets/flaw detection.

  3. Microstructures and Mechanical Properties of Friction Stir Spot Welded Aluminum Alloy AA2014

    NASA Astrophysics Data System (ADS)

    Babu, S.; Sankar, V. S.; Janaki Ram, G. D.; Venkitakrishnan, P. V.; Madhusudhan Reddy, G.; Prasad Rao, K.

    2013-01-01

    Friction stir spot welding (FSSW) is a relatively recent development, which can provide a superior alternative to resistance spot welding and riveting for fabrication of aluminum sheet metal structures. In the current work, FSSW experiments were conducted in 3-mm thick sheets of aluminum alloy 2014 in T4 and T6 conditions, with and without Alclad layers. The effects of tool geometry and welding process parameters on joint formation were investigated. A good correlation between process parameters, bond width, hook height, joint strength, and fracture mode was observed. The presence of Alclad layers and the base metal temper condition were found to have no major effect on joint formation and joint strength. Friction stir spot welds produced under optimum conditions were found to be superior to riveted joints in lap-shear and cross-tension tests. The prospects of FSSW in aluminum sheet metal fabrication are discussed.

  4. Effect of polymer coatings on fatigue strength of aluminum alloy 2024 box beams

    NASA Technical Reports Server (NTRS)

    Nordmark, G. E.; Kelsey, R. A.

    1972-01-01

    Previous investigators have shown that polymer coatings raise the fatigue strength of metals tested in air to about the same level as that of uncoated specimens tested in vacuum. The results are given of tests to determine if a polymer coating would improve the fatigue strength of built-up aluminum alloy members simulating aircraft construction. Aluminum alloy 2024-T4 riveted box beams were subjected to constant amplitude fatigue tests in air as well as in salt water fog. The coating did not improve the fatigue strength of beams tested in either environment. This is believed to result from the fact that most failures originated at rivet holes, which were isolated from both the coating and the environment.

  5. Tests of Aluminum-alloy Stiffened-sheet Specimens Cut from an Airplane Wing

    NASA Technical Reports Server (NTRS)

    Holt, Marshall

    1943-01-01

    The specimens used in the present tests were cut from an actual airplane wing of the stressed-skin type. The specimens thus obtained were not representative of the usual type of laboratory specimens because the stiffeners were not exactly parallel nor evenly spaced and, in one case, the skin consisted of pieces of sheet of different thicknesses. The test data obtained indicate that the buckling strain of stiffened curved sheet can be computed with reasonable accuracy by the equation given by Wenzek. The ultimate loads of the specimens when tested as flat sheet were within +/-11 percent of the product of the compressive yield strength and the cross-sectional area of the stiffeners. A rivet spacing equal to 98 times the sheet thickness was a source of weakness, and rivet spacings up to 36 times the sheet thickness appeared satisfactory.

  6. Handbook of structural stability part V : compressive strength of flat stiffened panels

    NASA Technical Reports Server (NTRS)

    Gerard, George

    1957-01-01

    A generalized crippling analysis for short monolithic panels with formed or extruded stiffeners is presented. Methods are presented for determining if riveted panels act in a monolithic manner and for determining the strength of those which do not. The failure modes of intermediate-length and long stiffened panels are discussed and methods given for estimating column strength. Theory and test data on optimum stiffened panels are presented and the various factors of importance in box types of construction are considered.

  7. Computational Analysis and Characterization of RC-135 External Aerodynamics

    DTIC Science & Technology

    2012-03-22

    the RJ has experienced structural damage. Computational fluid dynamics ( CFD ) was applied with the intention of characterizing the differences between...13 2.3 Computational Fluid Dynamics . . . . . . . . . . . . . . 18 2.3.1 Grid Generation: ANSYS ICEM CFD . . . . . 18 2.3.2 Flow Solver...another. Computational fluid dynamics ( CFD ) techniques are applied to both the Rivet Joint and Combat Sent variants with the objective of achieving a better

  8. Fastener Design Course [Workbook

    NASA Technical Reports Server (NTRS)

    Barrett, Richart T.

    1997-01-01

    Richard T. Barrett, Senior Aerospace Engineer of NASA Lewis Research Center presents a comprehensive course on fastener design. A recognized expert in the field of fastener technology Mr. Barrett combines lecture, charts, illustrations with real-world experiences. Topics covered include: materials, plantings and coatings, locking methods threads, joint stiffness, rivets, inserts, nut plates, thread lubricants, design criteria, etc. These presentation slides accompany the DVD.

  9. Composite Materials

    NASA Technical Reports Server (NTRS)

    1985-01-01

    Composites are lighter and stronger than metals. Aramid fibers like Kevlar and Nomex were developed by DuPont Corporation and can be combined in a honeycomb structure which can give an airplane a light, tough structure. Composites can be molded into many aerodynamic shapes eliminating rivets and fasteners. Langley Research Center has tested composites for both aerospace and non-aerospace applications. They are also used in boat hulls, military shelters, etc.

  10. High Cycle Random Fatigue Testing

    DTIC Science & Technology

    1976-07-01

    1. All aluminum assemblies made from same mill run of 2024-T81 bare sheef ; all titanium assemblies from same mill run of dAiMV annealed sheet. 2...SI>’ piiUH.iijwiijfH’PJPWHWii.1’ ■ .i-v-^ ■■ —- --^ f+l 2024-T8| Bore Aluminum At SO^F, Riveted SheeF , Rmdom Flmyr^ Z«!o M*^’$tr^«: xmr

  11. A Summary of Diagonal Tension Part I : Methods of Analysis

    NASA Technical Reports Server (NTRS)

    Kuhn, Paul; Peterson, James P; Levin, L Ross

    1952-01-01

    Previously published methods for stress and strength analysis of plane and curved shear webs working in diagonal tension are presented as a unified method. The treatment is sufficiently comprehensive and detailed to make the paper self-contained. Part 1 discusses the theory and methods for calculating the stresses and shear deflections of web systems as well as the strengths of the web, the stiffeners, and the riveting. Part 2, published separately, presents the experimental evidence. (author)

  12. Civil Engineering Corrosion Control. Volume 1. Corrosion Control - General

    DTIC Science & Technology

    1975-01-01

    caused by corrosion. Riveted boiler explosions have been known to result from stress corrosion or " caustic embrittlement". The use of welded pressure...Concentrated caustic at high temperatures, however, can pro- duce a serious form of hydrogen embrittlement - caustic em- brittlement - in many stressed ...steam, caustic embrittlement problems should not occur. - 4.15.8 Stress Corrosion of Various Structures. Stress Corrosion is discussed in paragraph 4.10

  13. Paint and Surface Preparation Training Program for Shipyard Personnel

    DTIC Science & Technology

    1979-01-01

    with an extra coat of paint.) A.7 Riveted joints should be free of gaps. Use insulation material or caulking to fill in pock- ets which cannot be...Pigments resist weathering. B. Pigments dissolve the resin making the paint flowable . C. Pigments provide color and hiding power. D. Pigments...They achieve their proper flowability by stirring. For two-package paints, the data sheet will in- dicate the ratio of catalyst to base such as 1

  14. Improving Land Armaments: Lessons from the Balkans. The U.S. Army Effort (Abbreviated)

    DTIC Science & Technology

    2004-09-01

    Guardrail Common Sensor (GRCS), Rivet Joint, JSTARS and NIMROD to communicate near real-time. This allowed for real-time queuing of surveillance assets...Communications US 3.1-69 Transitioning US TRI-TAC/MSE (Multiple Subscriber Equipment) switching systems from TACSAT to commercial IDNX required...from other systems, units or forces and to use the services so exchanged to enable them to operate effectively together In- transit visibility

  15. Deconstructing the skin: cytoarchitectural determinants of epidermal morphogenesis.

    PubMed

    Simpson, Cory L; Patel, Dipal M; Green, Kathleen J

    2011-08-23

    To provide a stable environmental barrier, the epidermis requires an integrated network of cytoskeletal elements and cellular junctions. Nevertheless, the epidermis ranks among the body's most dynamic tissues, continually regenerating itself and responding to cutaneous insults. As keratinocytes journey from the basal compartment towards the cornified layers, they completely reorganize their adhesive junctions and cytoskeleton. These architectural components are more than just rivets and scaffolds - they are active participants in epidermal morphogenesis that regulate epidermal polarization, signalling and barrier formation.

  16. A Theoretical Study of Landing Mat Behavior

    DTIC Science & Technology

    1969-07-01

    the end joint expcrience6 progressive eeteriora- tion uc ’-o - con:r ;itaticn oL mat breaks ( rivet filure, cracking, an. curling) [l21. The weakened...Establishment, Suffield s-69-4 Oct 1969 Dutch Friction -Cone Penetrometer Exploration of Research Area at Field 5, Eglin APB, Florida *S-69-5 Apr 1969 Cracking...Tests. 66 12. Comparison of Performance for Single- Wheel Tests . . . . . . . . .. . 67 13. End Joint Moment Transfer Deficiency Based Upon Uniform

  17. Effects Based Assessment in the United States Air Force

    DTIC Science & Technology

    2005-05-01

    during OIF includes: Predator and Global Hawk UAV, RC-135 Rivet Joint , E-8 JSTARS, E-3 AWACS, and overhead national assets. 59 Operation Iraqi Freedom...Moseley, Operation Iraqi Freedom (OIF) Joint Forces Air Component Commander (JFACC), succinctly described OIF assessment when he said, “BDA [was...only three weeks, the war was over. During these three weeks, Moseley’s air component provided crucial support to Frank’s joint campaign. In order

  18. Layered Sensing: Its Definition, Attributes, and Guiding Principles for AFRL Strategic Technology Development

    DTIC Science & Technology

    2008-05-01

    capabilities with current systems like Global Hawk, Predator, Rivet Joint , TR-1, AWACs and JSTARS. In addition, the USAF anticipates that its future...in support of other instruments of national power, and that traditional joint force organizational relationships may not be as effective for...demand access to space; b) sustaining war fighting capabilities; c) cyber security, forensics and assured battlespace networks; and d) self

  19. Current Procedures for Assessment of Battle-Damage Repair of Fixed-Wing Aircraft

    DTIC Science & Technology

    2010-05-01

    addition of ABDR Engineering training which focuses on thin-walled structural analysis and fastened joint design. ABDR engineers are typically assigned...Sheet metal thickness gauge – necessary for accurate measurement of skin panels. • Blind rivet depth gauge – necessary to prescribe the proper...Further damage  Accomplish Designated Missions  Contribute to the Battle  Deferment of Repairs for a “One Time” Flight or Self Recovery

  20. Interaction of Bearing and Tensile Loads on Creep Properties of Joints

    NASA Technical Reports Server (NTRS)

    Bodine, E G; Carlson, R L; Manning, G K

    1956-01-01

    The interaction of bearing and tensile loads on the creep behavior of joints was studied. A specimen was designed for this study which possessed some of the general features of pin and rivet joint connections and an apparatus was constructed to apply both bearing and tensile loads to the joint model. Deformation measurements were made by use of a photogrid printed on the joint model.

  1. Describing the Elephant: Framing a Discussion on Command and Control

    DTIC Science & Technology

    2014-08-01

    operations in support of combat- ant commanders. A master navigator with more than 4,200 flying hours, pri- marily in the RC-135 Rivet Joint and E-8C JSTARS...that term varies across the levels of war; by service, mediums, career fields, and platforms; and across the realms of academics, joint -requirements...the battlespace. Although designed to be platform agnostic, most of the articles incorporate recent experience with the Joint Sur- veillance Target

  2. Multi-Site Fatigue Testing and Characterization of Fuselage Panels from Aging Aircraft Structure

    DTIC Science & Technology

    2013-06-07

    Multi-site fatigue damage is a common problem in the riveted lap joint structure of aging aircraft. Modeling and characterization of such damage is...an especially daunting task. In this effort we present the results from fatigue tests which were performed on fuselage lap joints extracted from...in the lap joint . Some spot welded lap joint panels were also tested during the larger program; however, only the results from mechanically fastened

  3. Arthroscopic stabilization procedures for recurrent anterior shoulder instability.

    PubMed

    Yahiro, M A; Matthews, L S

    1989-11-01

    Anterior shoulder instability is a common and functionally disabling problem in young athletes. The goal in treatment of this condition is a stable, yet mobile, joint. Current methods now being utilized in the arthroscopic stabilization of the anterior shoulder include staple capsulorrhaphy, removable rivet capsulorrhaphy, cannulated screw fixation, and the transglenoid suture technique. These techniques and the clinical experience with each are reviewed, with an emphasis on providing stability, improving function, and allowing earlier rehabilitation in the unstable shoulder of the athlete.

  4. Toward Omniscient command: How to Lead in the Information Age

    DTIC Science & Technology

    2007-11-02

    to understand the tremendous value of both tangible assets (M1A1 Abrams Tank, RC-135 Rivet Joint , et cetera) and intangible assets (morale...and used information, and how it affected their leadership. The study will conduct a review and analysis of joint and service-specific leadership...The study will also place these leadership skills into the context of the Joint Operating Environment (JOE) to determine how these skills will

  5. Air Force Command and Control: The Need for Increased Adaptability

    DTIC Science & Technology

    2012-07-01

    classification issues limited the ability to conduct effective training for elements of the TACS. At times, RC­135 Rivet Joint operators were restricted from...electronic warfare officer. He has been published in such peri­ odicals as the Armed Forces Journal, Joint Force Quarterly, and Defense Analysis and in...lead to more effective and ef­ ficient operations in support of the joint force commander’s re­ quirements. Current and future operations demand this

  6. Through the Libyan Looking Glass

    DTIC Science & Technology

    2012-05-22

    included MQ-1 PREDATOR, MQ-4 GLOBAL HAWK, JSTARS and RIVET JOINT platforms.75 These aircraft were limited in number compared with operations in...Commander John S. Williamson, RAF Joint Forces Staff College Joint Advanced Warfighting School 7800 Hampton BLVD. Norfolk, VA 23511-1702 Approved for...Unclassified Unlimited 85 757-443-6301 NATIONAL DEFENSE UNIVERSITY JOINT FORCES STAFF COLLEGE JOINT ADVANCED WARFIGHTING SCHOOL           THROUGH THE

  7. Pointblank: Acts on the Eve of War, 1938-1939

    DTIC Science & Technology

    2012-06-01

    Throughout this process, I kept my sanity by riding bikes and running with classmates, thanks fellas. The conversations at lunch were riveting and I was...alone provide the means of victory. Sir Winston Churchill The ominous noise of jet engines pierces a calm, late afternoon in the desert as the... self -escort when pursuit assets were unable to escort the bombers deep into enemy territory.12 The bomber was flexible and unafraid, but ACTS also

  8. MCPLOTS: a particle physics resource based on volunteer computing

    NASA Astrophysics Data System (ADS)

    Karneyeu, A.; Mijovic, L.; Prestel, S.; Skands, P. Z.

    2014-02-01

    The mcplots.cern.ch web site ( mcplots) provides a simple online repository of plots made with high-energy-physics event generators, comparing them to a wide variety of experimental data. The repository is based on the hepdata online database of experimental results and on the rivet Monte Carlo analysis tool. The repository is continually updated and relies on computing power donated by volunteers, via the lhc@home 2.0 platform.

  9. Stability and Robustness Analysis Tools for Marine Robot Localization and Mapping Applications

    DTIC Science & Technology

    2009-06-01

    propeller, and shaft, and sometimes rivets and welds). DIDSON provides a range and bearing measurement associated with each pixel of each image... Springer - Verlag, 1990, pp. 167-193. [22] M. Csorba, Simultaneous Localisation and Map Building, PhD Thesis, University of Oxford, 1997. [23] G... Springer -Verlag, 2003, pp. 361-371. [39] E. Malis, “Stability Analysis of Invariant Visual Servoing and Robutness to Parametric Uncertainties,” A

  10. Prosthetic Tool For Holding Small Ferromagnetic Parts

    NASA Technical Reports Server (NTRS)

    Norton, William E.; Carden, James R.; Belcher, Jewell G., Jr.; Vest, Thomas W.

    1995-01-01

    Tool attached to prosthetic hand or arm enables user to hold nails, screws, nuts, rivets, and other small ferromagnetic objects on small magnetic tip. Device adjusted to hold nail or screw at proper angle for hammering or for use of screwdriver, respectively. Includes base connector with threaded outer surface and lower male member inserted in standard spring-action, quick-connect/quick-disconnect wrist adapter on prosthetic hand or arm.

  11. VIEW TO EAST OF THE NORTH END OF BASIN NO. ...

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

    VIEW TO EAST OF THE NORTH END OF BASIN NO. 1 (THE WESTERN-MOST BASIN) SHOWING THE CRANEWAY AND GALLERY BETWEEN BASINS NO. 1 AND 2. BASSWOOD BUOY TENDER AND THREE SMALL VESSELS ARE BERTHED IN BASIN NO. 1. LARGER VESSELS ARE BERTHED IN BASINS TO THE EAST, SEEN IN BACKGROUND - Rosie the Riveter National Historical Park, Graving Docks, Shipyard No. 3, Richmond, Contra Costa County, CA

  12. 13. SOUTHEAST TO SUCKER ROD WORK BENCH AND WOODEN SUCKER ...

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

    13. SOUTHEAST TO SUCKER ROD WORK BENCH AND WOODEN SUCKER ROD STORAGE RACKS ALONG EAST WALL OF FACTORY INTERIOR. AT THIS BENCH WORKERS RIVETED THREADED WROUGHT IRON CONNECTORS TO THE ENDS OF 20' LONG WOODEN SUCKER RODS (THE RODS WHICH EXTEND DOWNWARD IN THE WELL FROM THE GROUND SURFACE TO PISTON DISPLACEMENT PUMPS WHICH ACTUALLY ELEVATE WATER TO THE SURFACE). ROZNOR HEATER AT THE FAR RIGHT WAS ADDED CIRCA 1960. - Kregel Windmill Company Factory, 1416 Central Avenue, Nebraska City, Otoe County, NE

  13. An Analysis of the United States Naval Aviation Schedule Removal Component (SRC) Card Process

    DTIC Science & Technology

    2009-12-01

    guidance throughout this process; Ms. Jane Zimmerman, Logistics Automation Manager of COMFISCS, for making us part of the team and for her vision...an equal number of bolts, rivets and other fasteners; and 36 miles (58 kilometers) of electrical wire” ( Addams , 2003). Unlike the military’s use...increasing readiness around the Fleet. 85 LIST OF REFERENCES Addams , C. (2003, April 15). A world of service for the Boeing 737. Press release. Retrieved

  14. Australian DefenceScience. Volume 13, Number 4, Summer

    DTIC Science & Technology

    2006-01-01

    fuselage and cockpit, mid and aft fuselage, empennage , wing , wing and fuselage intersection, and finally engine nacelles. A photographic survey of...own rivet lines as a guide. Areas of high curvature in three dimensions, like the engine nacelles, empennage - fuselage intersection and wing -fuselage...tony.cox@dsto.defence.gov.au Design and illustration: Rebekah Meere Phone: 61 3 9626 7141 Fax: 61 3 9626 7133 e-mail: rebekah.meere

  15. Particle contamination from Martin Optical Black. [in design of barrel baffle of Infrared Astronomical Satellite

    NASA Technical Reports Server (NTRS)

    Young, P. J.; Noll, R.; Andreozzi, L.; Hope, J.

    1981-01-01

    The design of the barrel baffle of the Infrared Astronomical Satellite (IRAS) Optical Subsystem to minimize production of particulate contamination is described. The configuration of the 50-inch long, 28.5-inch diameter baffle required pop-rivet assembly after coating with Martin Optical Black for stray light suppression. An experiment to determine the contamination produced at assembly led to the modification of the baffle construction to preclude such damage to the coated surfaces.

  16. Literature Research on the Mechanical Properties of Fibre Composise Materials Analysis of the State of the Art. Volume I. (Schrifttumsrecherche zum Festigkeitsverhalten von Faserverbundwerkstoffen-Analyse des Standes der Technik-),

    DTIC Science & Technology

    1980-08-11

    elastic up to immedi- ately before fracture, breaking elongation is generally slight. These two modes of behaviour must be regarded as border-line cases , in...cross-section in the rivet line lies below the tensile strength of the undisturbed cross-section in the case of fibre composites in contrast to metals...air. In addition to the media air with humidity and the extreme borderline cases of vacuum and water, fibre composite components of load bearing

  17. SAR Product Improvements and Enhancements - SARprises

    DTIC Science & Technology

    2013-09-30

    in Germany, Steffen Grünler, published a paper on the potential of using spaceborne ATI systems to estimate mean river discharges [ D ]. RESULTS...directly involved, and to the River Inlet (RIVET) projects. 6 REFERENCES [1] Toporkov, J.V., D . Perkovic, G. Farquharson, M.A. Sletten, S.J. Frasier...2004JC002809, 17 pp., 2005. [3] Romeiser, R., A. Seibt-Winckler, M. Heineke, D . Eppel, Validation of current and bathymetry measurements in the German

  18. Experimental and Theoretical Investigation of Mechanically Fastened Composites

    DTIC Science & Technology

    1987-02-01

    30 1-2. Stress-Wave Rivet System ......... .................. .. 30 1-3. Metal Fastener Installed in Composite Structure...Microdatatizer System ............. .................... .. 125 5-1. Stress Resultants for Two Tandem Holes Equally Loaded . . . . 129 5-2. Moire Fringes of...number of materials systems were 0 considered; these were the so-called glass fiber reinforced polyster (GRP), glass fiber reinforced epoxy (GFRP), and

  19. Task Analysis - Aircraft Structural Maintenance AFSC 458X2

    DTIC Science & Technology

    1989-08-01

    PARTS USING ULTRASONIC CLEANERS 10346 CLEAN AIRCRAFT PARTS USING VAPOR DEGREASERS 10359 SPRAY CLEAN AIRCRAFT PARTS 10360 SPRAY CLEAN SUPPORT EQUIPMENT...tasks are as follows: ACTIVITIES: A summary of the actions performed during the task. We identified activities which: (a) summarize major parts of the...FASTENER HOLES 21 USE REAMING TOOLS 13 USE PNEUMATIC RIVET GUNS 12 APPLY PARTING AGENTS 11 USE MICROSHAVER 7 OPERATE HEATING/CURING EQUIPMENT 6 USE

  20. European Craft Training a Trip Report

    DTIC Science & Technology

    1985-12-01

    Raebarn House, England, 1982. 28. The Training of Craftsmen: Pipeworkers Information Paper No. 12, Shipbuilding Industry Training Board, Raebarn House... pipework together Shrink fitting Trimming sheet metal sections Hammering (forge work) Cold and hot riveting by hand and mechanically Hand mortising...tanks for pressure testing Tack welding — oxy-acetylene and electric Oxy-acetylene flame cutting with mandrel, trimming tanks and pipework

  1. In-flight measurements of the GA/W/-2 aerodynamic characteristics

    NASA Technical Reports Server (NTRS)

    Gregorek, G. M.; Hoffmann, M. J.; Weislogel, G. S.; Vogel, G. M.

    1977-01-01

    Flight tests of a new 13% General Aviation Airfoil - the GA(W)-2 - gloved full span onto the existing wing of a Beech Sundowner have generated chordwise pressure distributions and wake surveys. Section lift, drag and moment coefficients derived from these measurements verify wind tunnel data and theory predicting the performance of this airfoil. The effect of steps, rivets and surface coatings upon the drag of the GA(W)-2 was also evaluated.

  2. Intelligence and Electronic Warfare (IEW) System Fact Sheets

    DTIC Science & Technology

    2007-11-02

    DIA accredited CSP is compatible with TROJAN, MSE, DIN/ DSSCS as well as all TENCAP systems. A TIBS (RIVET JOINT) capability will be added in FY94. Other...via UHF SATCOM, and point-to-point terrestrial communications. The FAST CSP is compatible with TROJAN, MSE, DIN/ DSSCS as well as all TENCAP systems. A...with TROJAN, MSE, DIN/ DSSCS as well as other TENCAP systems. The SUCCESS additionally provides a TRAP/TADIX-B interface. The data acquisition system

  3. 75 FR 43397 - Airworthiness Directives; Piper Aircraft, Inc. Models PA-32R-301T and PA-46-350P Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-26

    ... couplings, part number (P/N) Lycoming 40D21162-340M or Eaton/Aeroquip 55677-340M with an improved design... coupling with a riveted, V-band exhaust coupling instead of stating the specific P/N to be replaced. Also... replace V-band exhaust couplings, P/N Lycoming 40D21162-340M or Eaton/Aeroquip 55677-340M with an...

  4. HOT METAL BRIDGE (NOTE: BUILDERS: JONES AND LAUGHLIN STEEL CA. ...

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

    HOT METAL BRIDGE (NOTE: BUILDERS: JONES AND LAUGHLIN STEEL CA. 1890), SOUTH PORTAL. THREE PIN CONNECTED CAMELBACK TRUSS SPANS, ONE SKEWED THROUGH TRUSS SPAN ON NORTH SIDE TRUSS BRIDGE, EAST OF HOT METAL BRIDGE BUILT BY AMERICAN BRIDGE COMPANY CA. 1910. (RIVETED MULTI-SPAN TRUSS). - Jones & Laughlin Steel Corporation, Pittsburgh Works, Morgan Billet Mill Engine, 550 feet north of East Carson Street, opposite South Twenty-seventh Street, Pittsburgh, Allegheny County, PA

  5. RIGGERS LOFT/PAINT SHOP/SHEET METAL SHOP, VIEW TO SOUTHEAST. THE PAINT ...

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

    RIGGERS LOFT/PAINT SHOP/SHEET METAL SHOP, VIEW TO SOUTHEAST. THE PAINT SHOP WAS LOCATED IN THE CLOSEST CORNER OF THE BUILDING. THE SHEET METAL SHOP WAS LOCATED IN THE CORNER OF THE BUILDING ON THE RIGHT. THE RIGGERS LOFT WAS LOCATED IN THE PORTION OF THE BUILDING OUT OF VIEW TO THE LEFT - Rosie the Riveter National Historical Park, Riggers Loft/Paint Shop/Sheet Metal Shop, 1322 Canal Boulevard, Richmond, Contra Costa County, CA

  6. A Low-cost Method to Identify Tubewells for Longitudinal Research on Arsenic in Groundwater

    PubMed Central

    Sugimoto, Jonathan D.; Ahmad, Salahuddin; Rashid, Mahbubur; Shamim, Abu Ahmed; Labrique, Alain B.

    2007-01-01

    Exposure to high concentrations of arsenic in tubewell groundwater from the shallow aquifers of Bangladesh could result in up to 300,000 arsenic-related cancer cases over the next four decades. Understanding the magnitude and temporal dynamics of this exposure, via longitudinal studies, is imperative for planning effective mitigation and management strategies. Appropriate methods are needed to identify tubewells for longitudinal sampling. A plastic band marked with a unique identification number was developed, and various methods for attaching the band to the tubewell were tested, resulting in the choice of a galvanized-iron split-rivet. Two follow-up surveys at two and 14 months post-banding assessed the durability and longevity under field conditions in the JiVitA Project area in rural, northwestern Bangladesh. After two months, ~96.0% of the original bands on 1,063 tubewells were functional, although the rivets were partially corroded. After 14 months, ~65% of a subsample of the bands were functional. With further improvements to the rivets, these bands offer an inexpensive, durable, enumeration technology for longitudinal studies on groundwater arsenic. PMID:18330072

  7. Structural analysis of Aircraft fuselage splice joint

    NASA Astrophysics Data System (ADS)

    Udaya Prakash, R.; Kumar, G. Raj; Vijayanandh, R.; Senthil Kumar, M.; Ramganesh, T.

    2016-09-01

    In Aviation sector, composite materials and its application to each component are one of the prime factors of consideration due to the high strength to weight ratio, design flexibility and non-corrosive so that the composite materials are widely used in the low weight constructions and also it can be treated as a suitable alternative to metals. The objective of this paper is to estimate and compare the suitability of a composite skin joint in an aircraft fuselage with different joints by simulating the displacement, normal stress, vonmises stress and shear stress with the help of numerical solution methods. The reference Z-stringer component of this paper is modeled by CATIA and numerical simulation is carried out by ANSYS has been used for splice joint presents in the aircraft fuselage with three combinations of joints such as riveted joint, bonded joint and hybrid joint. Nowadays the stringers are using to avoid buckling of fuselage skin, it has joined together by rivets and they are connected end to end by splice joint. Design and static analysis of three-dimensional models of joints such as bonded, riveted and hybrid are carried out and results are compared.

  8. Fracture analyses of thin films, interfaces, and joints

    NASA Astrophysics Data System (ADS)

    Beuth, Jack Lee, Jr.

    multi-site damage (multiple small fatigue cracks emerging from rivet holes along a single line of rivets) in the lap joints of the skins of aging aircraft. Stress intensity factors are plotted as a function of normalized crack length for two types of rivet contact conditions. The roles of transverse stresses and residual stresses induced by the riveting process are explored. The underlying cause of MSD cracking is investigated, including the potential influence of the shedding of load from one cracked rivet hole to a lesser cracked neighbor.

  9. Robotic collaborative technology alliance: an open architecture approach to integrated research

    NASA Astrophysics Data System (ADS)

    Dean, Robert Michael S.; DiBerardino, Charles A.

    2014-06-01

    The Robotics Collaborative Technology Alliance (RCTA) seeks to provide adaptive robot capabilities which move beyond traditional metric algorithms to include cognitive capabilities [1]. Research occurs in 5 main Task Areas: Intelligence, Perception, Dexterous Manipulation and Unique Mobility (DMUM), Human Robot Interaction (HRI), and Integrated Research (IR). This last task of Integrated Research is especially critical and challenging. Individual research components can only be fully assessed when integrated onto a robot where they interact with other aspects of the system to create cross-Task capabilities which move beyond the State of the Art. Adding to the complexity, the RCTA is comprised of 12+ independent organizations across the United States. Each has its own constraints due to development environments, ITAR, "lab" vs "real-time" implementations, and legacy software investments from previous and ongoing programs. We have developed three main components to manage the Integration Task. The first is RFrame, a data-centric transport agnostic middleware which unifies the disparate environments, protocols, and data collection mechanisms. Second is the modular Intelligence Architecture built around the Common World Model (CWM). The CWM instantiates a Common Data Model and provides access services. Third is RIVET, an ITAR free Hardware-In-The-Loop simulator based on 3D game technology. RIVET provides each researcher a common test-bed for development prior to integration, and a regression test mechanism. Once components are integrated and verified, they are released back to the consortium to provide the RIVET baseline for further research. This approach allows Integration of new and legacy systems built upon different architectures, by application of Open Architecture principles.

  10. Acoustic tests on a new motor generator system for the Minuteman launch control centers at Alpha 01 and Sierra 00, Malmstrom AFB, Montana

    NASA Astrophysics Data System (ADS)

    Fairman, Terry M.

    1991-05-01

    Field tests of the acoustic performance of a new motor generator system (MGS) were performed at Minuteman Launch Control Centers (LCC) Alpha 01 and Sierra 00, Malmstrom AFB, MT. This same MGS unit was accepted for use after the Hill Engineering Test Facilities (HETF) acoustic performance studies conducted in 1988. Rivet Mile from the Ogden ALC began installation of the new MGS at Malmstrom in the spring of 1990. Performance tests were requested by 00-ALC/MMGRMM, and SAC, to compare with the HETF data and document the LCC acoustic environment with the new MGS operating in a field setting. This report presents our findings.

  11. Inspecting for widespread fatigue damage: Is partial debonding the key?

    NASA Technical Reports Server (NTRS)

    Brewer, John

    1994-01-01

    Experimental and analytical results indicate that cracks can initiate, grow, and coalesce more rapidly in fuselage lap joints that have experienced partial or complete debonding. Computational analysis in this paper shows that stress concentrations and stress intensity factors at the rivet holes are far less severe when the bond is intact. Debonding hastens the initiation of widespread fatigue cracks and significantly increases crack growth rate. Thus, debonded regions serve as "breeding grounds" for widespread fatigue damage. Therefore, the effectiveness of lap joint inspection programs may be enhanced if detailed inspections are focused on areas in which debonding has been detected.

  12. Triton 2 (1B)

    NASA Technical Reports Server (NTRS)

    Clark, Michelle L.; Meiss, A. G.; Neher, Jason R.; Rudolph, Richard H.

    1994-01-01

    The goal of this project was to perform a detailed design analysis on a conceptually designed preliminary flight trainer. The Triton 2 (1B) must meet the current regulations in FAR Part 23. The detailed design process included the tasks of sizing load carrying members, pulleys, bolts, rivets, and fuselage skin for the safety cage, empennage, and control systems. In addition to the regulations in FAR Part 23, the detail design had to meet established minimums for environmental operating conditions and material corrosion resistance.

  13. Lagrangian Tracer Transport and Dispersion in Tidal Inlets and River Mouths

    DTIC Science & Technology

    2013-01-31

    time capable infrared ( IR ) sensor, and (4) lidar measurements for surface gravity waves. Example airborne temperature and dye observations are shown...ICW calm none 19 c 5:54 Flood 30 Deep Channel onshore large 20 c 1:12 Ebb 24 mid -Inlet light small Table 1: Summary of RIVET-I dye releases at New...0.5 days) after the primary 1500 Daytime IR -derived relative SST (deg C) 04 03 02 0 1 -1500 1500 1000 Hyperspectrai Dye concentration (no

  14. 10. VIEW TO NORTHEAST FROM WITHIN SOUTHWEST BAY, LOOKING THROUGH ...

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

    10. VIEW TO NORTHEAST FROM WITHIN SOUTHWEST BAY, LOOKING THROUGH CENTER BAY AND INTO NORTHEAST BAY. NOTE TRAVELING BRIDGE CRANE OVERHEAD AND SWINGING BOOM CRANES ATTACHED TO COLUMNS ON RIGHT AND LEFT. NOTE ALSO THE DIFFERENCE IN TRUSSES SUPPORTING CRANEWAY TRACKS FOR SIDE BAYS AND CENTER BAY. TRUSSES SUPPORTING CRANEWAY TRACKS IN SIDE BAYS (CENTER FOREGROUND AND FAR BACKGROUND) ARE HOWE TRUSSES WITH WOOD DIAGONALS AND STEEL VERTICALS. TRUSSES SUPPORTING CRANEWAY TRACKS IN CENTER BAY (MID BACKGROUND) ARE PRATT TRUSSES WITH WOOD VERTICALS AND DIAGONALS. - Rosie the Riveter National Historical Park, Auxiliary Plate Shop, 912 Harbour Way, Richmond, Contra Costa County, CA

  15. Aircraft Excrescence Drag

    DTIC Science & Technology

    1981-07-01

    ACD EST .0010- .0010 jy ’ SOLID SYMBOLS, AREA PRO-RATED C 0 SEE PARA 4.2.1.2 0 .0010 .0020 0 .0010 .0020 ACDExP ACDExP Figure 4. 1 Fastener Drug ...004 00 h/d Figure 4.5 Drug of Countersink( Rivets (10 (4) Special shapes (Three-Dimensional) Hoerner (Figures 13 and 14) shows single "independent...j.m . :: ::- ji h ... ..... .. .... .. 0,8 1;,1 0 2 4 6 8 1.0 t/lI 4 Figure 4.44 Drug of Spanwise Ledges of Different Profiles I " ’ ’ 1 I[ "i

  16. Analytical Characterization of CFRP Laser Treated by Excimer Laser Radiation

    NASA Astrophysics Data System (ADS)

    Kreling, S.; Fischer, F.; Delmdahl, R.; Gäbler, F.; Dilger, K.

    Due to the increasing interest in lightweight structures, carbon-fiber reinforced plastics are increasingly applied, especially in the transportation industry. An interesting technology for joining these materials is adhesive bonding due to numerous advantages compared to conventional techniques like riveting. However, to achieve a strong and durable bond, surface pre-treatment is necessary to remove residues of release agents that are transferred to the surface during manufacturing. This paper describes analytical experiments, namely SEM and XPS, performed on CFRP surfaces pre-treated with 308 nm excimer laser radiation.

  17. Micromechanics of compression failures in open hole composite laminates

    NASA Technical Reports Server (NTRS)

    Guynn, E. Gail; Bradley, Walter L.

    1987-01-01

    The high strength-to-weight ratio of composite materials is ideally suited for aerospace applications where they already are used in commercial and military aircraft secondary structures and will soon be used for heavily loaded primary structures. One area impeding the widespread application of composites is their inherent weakness in compressive strength when compared to the tensile properties of the same material. Furthermore, these airframe designs typically contain many bolted or riveted joints, as well as electrical and hydraulic control lines. These applications produce areas of stress concentration, and thus, further complicate the compression failure problem. Open hole compression failures which represent a typical failure mode for composite materials are addressed.

  18. The Effect of Surface Irregularities on Wing Drag. II - Lap Joints. 2; Lap Joints

    NASA Technical Reports Server (NTRS)

    Hood, Manley J.

    1938-01-01

    Tests have been made in the NACA 8-foot high-speed wind tunnel of the drag caused by four types of lap joint. The tests were made on an airfoil of NACA 23012 section and 5-foot chord and covered in a range of speeds from 80 to 500 miles per hour and lift coefficients from 0 to 0.30. The increases in profile drag caused by representative arrangements of laps varied from 4 to 9%. When there were protruding rivet heads on the surface, the addition of laps increased the drag only slightly. Laps on the forward part of a wing increased the drag considerably more than those farther back.

  19. Inspecting for widespread fatigue damage: Is partial debonding the key?

    NASA Astrophysics Data System (ADS)

    Brewer, John

    1994-09-01

    Experimental and analytical results indicate that cracks can initiate, grow, and coalesce more rapidly in fuselage lap joints that have experienced partial or complete debonding. Computational analysis in this paper shows that stress concentrations and stress intensity factors at the rivet holes are far less severe when the bond is intact. Debonding hastens the initiation of widespread fatigue cracks and significantly increases crack growth rate. Thus, debonded regions serve as "breeding grounds" for widespread fatigue damage. Therefore, the effectiveness of lap joint inspection programs may be enhanced if detailed inspections are focused on areas in which debonding has been detected.

  20. 13. Detail, downstream side of Bridge Number 310.58, showing lower ...

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

    13. Detail, downstream side of Bridge Number 310.58, showing lower chord connection, view to southeast, 210mm lens. The riveted portion of the bottom chord is at left, joined at the pin connection to the eyebars. The vertical intermediate post is a compression member, and is attached to one end of a floor beam that spans transversely below the bridge floor. There are paired diagonals to the left of the intermediate post, with a turnbuckled counter to rising diagonally to the right. The diagonals below the floor are bottom lateral members. - Southern Pacific Railroad Shasta Route, Bridge No. 310.58, Milepost 310.58, Sims, Shasta County, CA

  1. Estimating the Cost of Composite Material Airframes Using the Rand Corporation Development and Procurement Costs of Aircraft Parametric Model (DAPCA III).

    DTIC Science & Technology

    1983-09-01

    shapes, rubber press CED-A-24 4.1-67 beaded, corrogated panels, rubber press DICE 1 4.1-91 summnary of design influences DICE 2 4.1-92 joggles (make end...4.4-37 extrusion curved shapes CED-EXTN-11 4.4-39 extrusion curved panels DICE-EXTN-1 4.4-44 extusion joggle cost DICE-EXTN-3 4.4-36 extrusion heat...feet/.1 thick T62 temper 144 sq in -’ Rivets CED-MFA-I 538 + 4 each intersection step 2 CED-MFA-3 24 feet Joggles DICE-2 8 PART 2: fuselage skin 96 X 36

  2. 3M heavy duty roto peen: Baseline report; Summary

    SciTech Connect

    1997-07-31

    The roto peen scaler allows for the selective removal of concrete substrates. The peen is a tungsten carbide shot brazed to a hardened steel rivet that is supported by a heavy duty flexible flap. The peens are coupled with a commercially available piece of equipment that is used to scabble or remove the concrete. The scabbled debris is then collected into 55 gallon drums by means of a vacuum system. The safety and health evaluation during the human factors assessment focused on two main areas: noise and dust.

  3. Finite Element Model Development For Aircraft Fuselage Structures

    NASA Technical Reports Server (NTRS)

    Buehrle, Ralph D.; Fleming, Gary A.; Pappa, Richard S.; Grosveld, Ferdinand W.

    2000-01-01

    The ability to extend the valid frequency range for finite element based structural dynamic predictions using detailed models of the structural components and attachment interfaces is examined for several stiffened aircraft fuselage structures. This extended dynamic prediction capability is needed for the integration of mid-frequency noise control technology. Beam, plate and solid element models of the stiffener components are evaluated. Attachment models between the stiffener and panel skin range from a line along the rivets of the physical structure to a constraint over the entire contact surface. The finite element models are validated using experimental modal analysis results.

  4. [State of vegetative regulation in workers exposed to vibration at work during industrial implementation of hi-tech pneumoinstruments].

    PubMed

    Drobyshev, V A; Shpagina, L A; Panacheva, L A; Gerasimenko, O N; Abramovich, S G; Smirnova, I N

    2016-01-01

    The study was conducted on aircraft-building enterprise during production microcycle (before working shift start, during last working hour and in an hour after the shift end)--spectral analysis covered variability of heart rhythm in 70 male assembler riveters aged 25-59, divided into 2 groups in accordance with industrial equipment used. The group 1 used standard vibroinstrument, the group 2--pneumoinstruments with low vibration velocity parameters. Triple study during the working shift revealed in group 2 an adequate reaction of vegetative nervous system to vibration, in group 1 a negative trend was seen with centralization of regulatory processes and absence of adequate recovery in an hour after work.

  5. Column strength of tubes elastically restrained against rotation at the ends

    NASA Technical Reports Server (NTRS)

    Osgood, William R

    1938-01-01

    Report presents the results of a study made of the effects of known end restraint on commercially available round and streamline tubing of chromium-molybdenum steel, duralumin, stainless steel, and heat-treated chromium-molybdenum steel; and a more accurate method than any previously available, but still a practical method, was developed for designing compression members in riveted or welded structures, particularly aircraft. Two hundred specimens were tested as short, medium-length, and long columns with freely supported ends or elastically restrained ends. Tensile and compressive tests were made on each piece of original tubing from which column specimens were cut.

  6. Fracture mechanics research at NASA related to the aging commercial transport fleet

    NASA Astrophysics Data System (ADS)

    Newman, James C., Jr.; Harris, Charles E.

    1992-07-01

    NASA is conducting the Airframe Structural Integrity Program in support of the aging commercial transport fleet. This interdisciplinary program is being worked in cooperation with the U.S. airframe manufacturers, airline operators, and the FAA. Advanced analysis methods are under development and an extensive testing program is under way to study fatigue crack growth and fracture in complex built-up shell structures. Innovative nondestructive examination technologies are also being developed to provide large area inspection capability to detect corrosion, disbonds, and cracks. Recent fracture mechanics results applicable to predicting the growth of cracks under monotonic and cyclic loading at rivets in fuselage lap-splice joints are reviewed.

  7. 19. VIEW TO SOUTHWEST OF FIRST FLOOR SHOWING CONVEYOR FOR ...

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

    19. VIEW TO SOUTHWEST OF FIRST FLOOR SHOWING CONVEYOR FOR MOVING MATERIAL TO SECOND FLOOR. (NOTE: THIS IS NOT AN ORIGINAL CONVEYOR FOR MOVING BODY PARTS) STAIRS IN BACKGROUND LEAD TO SECOND FLOOR VIA TOILET ROOM NO. 4 AND COAT ROOM AT MEZZANINES LEVEL SITUATED BETWEEN THE TWO SETS OF STAIRS. THERE ARE THREE OTHER TOILET/COAT ROOM MEZZANINES TO THE NORTH LOCATED ALONG THE WALL BETWEEN THE FIRST AND SECOND FLOORS, BEHIND AND TO THE LEFT OF THE STAIRS IS A FREIGHT ELEVATOR SHAFT. - Rosie the Riveter National Historical Park, Ford Assembly Plant, 1400 Harbour Way South, Richmond, Contra Costa County, CA

  8. Detailed finite element analysis and preliminary study of the effects of friction and fastener pre-tension on the mechanical behavior of fastened built-up members

    NASA Astrophysics Data System (ADS)

    Bonachera Martin, Francisco Javier

    The characterization of fatigue resistance is one of the main concerns in structural engineering, a concern that is particularly important in the evaluation of existing bridge members designed or erected before the development of fatigue design provisions. The ability of a structural member to develop alternate load paths after the failure of a component is known as member-level or internal redundancy. In fastened built-up members, these alternate load paths are affected by the combination of fastener pre-tension and friction between the structural member components in contact. In this study, a finite element methodology to model and analyze riveted and bolted built-up members was developed in ABAQUS and validated with experimental results. This methodology was used to created finite element models of three fastened plates subjected to tension, in which the middle plate had failed, in order to investigate the fundamental effects of combined fastener pre-tension and friction on their mechanical behavior. Detailed finite element models of riveted and bolted built-up flexural members were created and analyze to understand the effect of fastener pre-tension in member-level redundancy and resistance to fatigue and fracture. The obtained results showed that bolted members are able to re-distribute a larger portion of the load away from the failing component into the rest of the member than riveted members, and that this transfer of load also took place over a smaller length. Superior pre-tension of bolts, in comparison to rivets, results in larger frictional forces that develop at the contact interfaces between components and constitute additional alternate load paths that increase member-level redundancy which increase the fatigue and fracture resistance of the structural member during the failure of one of its components. Although fatigue and fracture potential may be mitigated by compressive stresses developing around the fastener hole due to fastener pre-tension, it

  9. Fastener Design Manual

    NASA Technical Reports Server (NTRS)

    Barrett, Richard T.

    1990-01-01

    This manual was written for design engineers to enable them to choose appropriate fasteners for their designs. Subject matter includes fastener material selection, platings, lubricants, corrosion, locking methods, washers, inserts, thread types and classes, fatigue loading, and fastener torque. A section on design criteria covers the derivation of torque formulas, loads on a fastener group, combining simultaneous shear and tension loads, pullout load for tapped holes, grip length, head styles, and fastener strengths. The second half of this manual presents general guidelines and selection criteria for rivets and lockbolts.

  10. Personal exposure to asbestos and respiratory health of heavy vehicle brake mechanics.

    PubMed

    Cely-García, María Fernanda; Torres-Duque, Carlos A; Durán, Mauricio; Parada, Patricia; Sarmiento, Olga Lucía; Breysse, Patrick N; Ramos-Bonilla, Juan P

    2015-01-01

    Asbestos brake linings and blocks are currently used in heavy vehicle brake repair shops (BRSs) in Bogotá, Colombia. Some brake products are sold detached from their supports and without holes, requiring manipulation before installation. The aim of this study was to assess asbestos exposures and conduct a preliminary evaluation of respiratory health in workers of heavy vehicles in BRSs. To estimate asbestos exposures, personal and area samples were collected in two heavy vehicle BRSs. Each shop was sampled during six consecutive days for the entire work shift. Personal samples were collected on 10 workers including riveters, brake mechanics, and administrative staff. Among workers sampled, riveters had the highest phase contrast microscopy equivalent (PCME) asbestos concentrations, with 8-h time-weighted average (TWA) personal exposures ranging between 0.003 and 0.157 f/cm(3). Respiratory health evaluations were performed on the 10 workers sampled. Three workers (30%) had circumscribed pleural thickening (pleural plaques), with calcifications in two of them. This finding is strongly suggestive of asbestos exposure. The results of this study provide preliminary evidence that workers in heavy vehicle BRSs could be at excessive risk of developing asbestos-related diseases.

  11. The morphology of the digestive tract and respiratory organs of the holothurian Cladolabes schmeltzii (Holothuroidea, Dendrochirotida).

    PubMed

    Kamenev, Ya O; Dolmatov, I Yu; Frolova, L T; Khang, Nguyen An

    2013-04-01

    The microanatomy of the digestive and respiratory systems of the holothurian Cladolabes schmeltzii was studied. The digestive tube of C. schmeltzii is divided into seven parts. The pharynx, esophagus, and stomach are lined with cuticular immersed epithelium. In these regions, the epithelial cells are connected via desmosomes, septate junctions, and rivet-like structures. The presence of the cuticle and rivet-like structures suggests an ectodermal origin for these parts of the digestive tube. The luminal intestinal epithelium is formed by vesicular enterocytes, which have different structures in different intestinal regions. Moreover, the epithelium of the first descending part of the intestine contains the granular enterocytes. The respiratory system consists of paired respiratory trees lined by a luminal epithelium that is formed by cells of irregular shape. The apical surface of these epithelial cells has few lamellae. The cells are connected to each other through a system of intercellular junctions, consisting of both desmosomes and well-developed septate junctions. The coelomic epithelium of the intestine and the respiratory trees consists of peritoneal and myoepithelial cells.

  12. Design, fabrication, installation and flight service evaluation of a composite cargo ramp skin on a model CH-53 helicopter

    NASA Technical Reports Server (NTRS)

    Lowry, D. W.; Rich, M. J.

    1983-01-01

    The installation of a composite skin panel on the cargo ramp of a CH-530 marine helicopter is discussed. The composite material is of Kevlar/Epoxy (K/E) which replaces aluminum outer skins on the aft two bays of the ramp. The cargo ramp aft region was selected as being a helicopter airframe surface subjected to possible significant field damage and would permit an evaluation of the long term durability of the composite skin panel. A structural analysis was performed and the skin shears determined. Single lap joints of K/E riveted to aluminum were statically tested. The joint tests were used to determine bearing allowables and the required K/E skin gage. The K/E skin panels riveted to aluminum edge members were tested in a shear fixture to confirm the allowable shear and bearing strengths. Impact tests were conducted on aluminum skin panels to determine energy level and damage relationship. The K/E skin panels of various ply orientations and laminate thicknesses were then impacted at similar energy levels. The results of the analysis and tests were used to determine the required K/E skin gages in each of the end two bays of the ramp.

  13. Characterization of lap joints laser beam welding of thin AA 2024 sheets with Yb:YAG disk-laser

    NASA Astrophysics Data System (ADS)

    Caiazzo, Fabrizia; Alfieri, Vittorio; Cardaropoli, Francesco; Sergi, Vincenzo

    2012-06-01

    Lap joints obtained by overlapping two plates are widely diffused in aerospace industry. Nevertheless, because of natural aging, adhesively bonded and riveted aircraft lap joints may be affected by cracks from rivets, voids or corrosion. Friction stir welding has been proposed as a valid alternative, although large heat affected zones are produced both in the top and the bottom plate due to the pin diameter. Interest has therefore been shown in studying laser lap welding as the laser beam has been proved to be competitive since it allows to concentrate the thermal input and increases productivity and quality. Some challenges arise as a consequence of aluminum low absorptance and high thermal conductivity; furthermore, issues are due to metallurgical challenges such as both micro and macro porosity formation and softening in the fused zone. Welding of AA 2024 thin sheets in a lap joint configuration is discussed in this paper: tests are carried out using a recently developed Trumpf TruDisk 2002 Yb:YAG disk-laser with high beam quality which allows to produce beads with low plates distortion and better penetration. The influence of the processing parameters is discussed considering the fused zone extent and the bead shape. The porosity content as well as the morphological features of the beads have been examined.

  14. 3M heavy duty roto peen: Baseline report

    SciTech Connect

    1997-07-31

    The heavy-duty roto peen technology was being evaluated at Florida International University (FIU) as a baseline technology. It is a commercially available technology and has been used for various projects at locations throughout the country. In conjunction with FIU`s evaluation of efficiency and cost, this report covers the human factors assessment for safety and health issues. The heavy-duty roto peen allows for the selective removal of concrete substrates. The peen is a tungsten carbide shot brazed to a hardened steel rivet that is supported by a heavy-duty flexible flap. The shot rivet is kept captive to the tool by mounting the roto peen in a slotted hub. The heavy-duty roto peen is designed to be used with several commercially available pieces of equipment. The equipment being used will determine the width of each pass. The equipment being used with the roto peen is then connected to a vacuum system for dust collection during scabbling. The safety and health evaluation during the human factors assessment focused on two main areas: noise and dust.

  15. Stress concentrations for straight-shank and countersunk holes in plates subjected to tension, bending, and pin loading

    NASA Technical Reports Server (NTRS)

    Shivakumar, K. N.; Newman, J. C., Jr.

    1992-01-01

    A three dimensional stress concentration analysis was conducted on straight shank and countersunk (rivet) holes in a large plate subjected to various loading conditions. Three dimensional finite element analysis were performed with 20 node isoparametric elements. The plate material was assumed to be linear elastic and isotropic, with a Poisson ratio of 0.3. Stress concentration along the bore of the hole were computed for several ratios of hole radius to plate thickness (0.1 to 2.5) and ratios of countersink depth to plate thickness (0.25 to 1). The countersink angles were varied from 80 to 100 degrees in some typical cases, but the angle was held constant at 100 degrees for most cases. For straight shank holes, three types of loading were considered: remote tension, remote bending, and wedge loading in the hole. Results for remote tension and wedge loading were used to estimate stress concentration for simulated rivet in pin loading. For countersunk holes only remote tension and bending were considered. Based on the finite element results, stress concentration equations were developed. Whenever possible, the present results were compared with other numerical solutions and experimental results from the literature.

  16. Experimental studies of mechanical joints by automated grating (moire) interferometry

    NASA Astrophysics Data System (ADS)

    Dymny, G.; Kujawinska, M.; Salbut, L.; Boronski, D.

    2005-06-01

    Current design, analysis and control engineering applications require effective experimental methodologies and tools for determination of displacement and strain fields as well as material characterization. One of the most important problem in engineering objects is proper design and quality of joints between elements in the form of welds, glued and riveted joints and many others. Specificly the fatigue and fracture mechanics problems in joints are difficult to analyze numerically, therefore they need experimental support. In the paper we present the results of static, dynamic and fatigue experiments performed by grating (moire) interferometry systems. These full-field optical extensometers provide information about in-plane displacement field (u,v) and strain fields (ɛx, ɛy, γxy) in the region of a joint subjected to various modes of loads. It is shown that proper design of full-field extensometer (insensitivity to vibration, good quality of interferogram, automatic analysis of long series of interferograms) allows to use it efficiently directly at conventional loading machine in workshop environment and for long term fatigue tests. In the paper we present results of studies of: conventional laser welds (static, fatigue tests), friction stir weld (static tests), riveted joint (static, fatigue tests). The methodology of determination of local material constants in different zones of a joint (inc. Poisson ratio, Young"s modulus) is given. The future trends in hybrid experimental-numerical analysis of joints in conventional and novel material are discussed.

  17. 3M heavy duty roto peen: Baseline report; Greenbook (chapter)

    SciTech Connect

    1997-07-31

    The heavy-duty roto peen technology is being evaluated at Florida International University (FIU) as a baseline technology. It is a commercially available technology and has been used for various projects at locations throughout the country. In conjunction with FIU`s evaluation of efficiency and cost, this report covers the human factors assessment for safety and health issues. The heavy-duty roto peen allows for the selective removal of concrete substrates. The peen is a tungsten carbide shot brazed to a hardened steel rivet that is supported by a heavy-duty flexible flap. The shot rivet is kept captive to the tool by mounting the roto peen in a slotted hub. The heavy-duty roto peen is designed to be used with several commercially available pieces of equipment. The equipment being used will determine the width of each pass. The equipment being used with the roto peen is then connected to a vacuum system for dust collection during scabbling. The safety and health evaluation during the human factors assessment focused on two main areas: noise and dust.

  18. Fracture Analysis of the FAA/NASA Wide Stiffened Panels

    NASA Technical Reports Server (NTRS)

    Seshadri, B. R.; Newman, J. C., Jr.; Dawicke, D. S.; Young, R. D.

    1998-01-01

    This paper presents the fracture analyses conducted on the FAA/NASA stiffened and unstiffened panels using the STAGS (STructural Analysis of General Shells) code with the critical crack-tip-opening angle (CTOA) fracture criterion. The STAGS code with the "plane-strain" core option was used in all analyses. Previous analyses of wide, flat panels have shown that the high-constraint conditions around a crack front, like plane strain, has to be modeled in order for the critical CTOA fracture criterion to predict wide panel failures from small laboratory tests. In the present study, the critical CTOA value was determined from a wide (unstiffened) panel with anti-buckling guides. The plane-strain core size was estimated from previous fracture analyses and was equal to about the sheet thickness. Rivet flexibility and stiffener failure was based on methods and criteria, like that currently used in industry. STAGS and the CTOA criterion were used to predict load-against-crack extension for the wide panels with a single crack and multiple-site damage cracking at many adjacent rivet holes. Analyses were able to predict stable crack growth and residual strength with a few percent (5%) of stiffened panel tests results but over predicted the buckling failure load on a unstiffened panel with a single crack by 10%.

  19. Molecular tectonics: tuning the dimensionality and topology of extended cyanocuprate networks using a bisamidinium cation.

    PubMed

    Ferlay, Sylvie; Dechambenoit, Pierre; Kyritsakas, Nathalie; Hosseini, Mir Wais

    2013-08-28

    Upon combining KCu(CN)2 with six different symmetrical dicationic bisamidinium moieties possessing different shapes and geometries, seven new coordination networks of the cyanocuprate type displaying 1-, 2- and 3-D dimensionality have been obtained. The formation of networks results from the interconnection of Cu(i) centres by cyanide anions through different bridging modes. The organic dicationic tectons interact with the anionic networks by charge-assisted H-bonds and, depending on their geometric features, they play different structuring roles. In the case of the 1D cyanocuprate networks, the organic cation interconnects consecutive anionic chains, increasing thus the overall dimensionality of the arrangement to 2D. For the 2D networks, either riveting or intercalation has been observed. For the riveting case, either the process takes place only between two consecutive sheets leading to a double layer type arrangement and thus without an increase of dimensionality, or between consecutive 2D networks in an alternate fashion. In the latter case, the dimensionality of the overall architecture is increased to 3 as for the intercalated case. For the 3D architectures, the dicationic moieties are located within the generated channels.

  20. Differential regulation of Salmonella typhimurium genes involved in O-antigen capsule production and their role in persistence within tomato fruit.

    PubMed

    Marvasi, Massimiliano; Cox, Clayton E; Xu, Yimin; Noel, Jason T; Giovannoni, James J; Teplitski, Max

    2013-07-01

    Enteric pathogens, including non-typhoidal Salmonella spp. and enterovirulent Escherichia coli, are capable of persisting and multiplying within plants. Yet, little is still known about the mechanisms of these interactions. This study identified the Salmonella yihT gene (involved in synthesis of the O-antigen capsule) as contributing to persistence in immature tomato fruit. Deletion of yihT reduced competitive fitness of S. enterica sv. Typhimurium in green (but not ripe, regardless of color) tomato fruit by approximately 3 logs. The yihT recombinase-based in vivo expression technology (RIVET) reporter was strongly activated in unripe tomato fruit, and fitness of the mutant inversely correlated with the level of the yihT gene expression. Expression of yihT in mature tomato fruit was low, and yihT did not affect competitive fitness within mature fruit. To better understand the molecular basis of the phenotype, behaviors of the yihT RIVET reporter and the yihT mutant were tested in tomato fruit defective in ethylene signaling. These experiments suggest a role for functional ethylene-mediated signaling in the persistence of Salmonella spp. within tomato fruit. Furthermore, jasmonic acid and its precursors strongly reduced expression of yihT.

  1. Optical characterization of LDEF contaminant film

    NASA Technical Reports Server (NTRS)

    Blakkolb, Brian K.; Ryan, Lorraine E.; Bowen, Howard S.; Kosic, Thomas J.

    1993-01-01

    Dark brown molecular film deposits were found at numerous locations on the Long Duration Exposure Facility (LDEF) and have been documented in great detail by several investigators. The exact deposition mechanism for these deposits is as yet unknown, although direct and scattered atomic oxygen, and solar radiation interacting with materials outgassing products have all been implicated in the formation process. Specimens of the brown molecular film were taken from below the flange of the experimental tray located at position D10 on the LDEF. The tray was one of two, comprising the same experiment, the other being located on the wake facing side of the LDEF satellite at position B4. Having access to both trays, we were able to directly compare the effect that orientation with respect to the atomic oxygen flux vector had on the formation of the brown molecular film deposits. The film is thickest on surfaces facing toward the exterior, i.e. the tray corner, as can be seen by comparing the lee and wake aspects of the rivets. The patterns appear to be aligned not with the velocity vector but with the corner of the tray suggesting that flux to the surface is due to scattered atomic oxygen rather than direct ram impingement. The role of scattered flux is further supported by more faint plume patterns on the sides of the tray. The angle of these plumes is strongly aligned with the ram direction but the outline of the deposit implies that incident atoms are scattered by collisions with the edges of the opening resulting in a directed, but diffuse, flux of atomic oxygen to the surface. Spectral reflectance measurements in the 2 to 10 micron (4000 to 1000 wavenumbers) spectral range are presented for the film in the 'as deposited' condition and for the free standing film. The material was analyzed by FTIR (Fourier Transform Infrared) microspectroscopy using gold as the reference standard. The 'as deposited' specimen was on an aluminum rivet taken from beneath the tray flange

  2. Metal of cavitation erosion of a hydrodynamic reactor

    NASA Astrophysics Data System (ADS)

    Zakirzakov, A. G.; Brand, A. E.; Petryakov, V. A.; Gordievskaya, E. F.

    2017-02-01

    Cavitation erosion is a major cause of the petroleum equipment hydraulic erosion, which leads to the metal weight loss of the equipment and its breakdown, which can be followed by the full stop of the plant or company work. The probability of the metal weight loss and equipment failure can be reduced by the use of special protective coatings or rivets, made of the sacrificial metals, the use of which significantly increases the service life and the production equipment reliability. The article investigates the cavitation erosion effect, occurred under the condition of the advanced hydrodynamic cavitation on the hydrodynamic cavitation reactor. This article presents the results of the experiments and recommendations for increasing the operational resource.

  3. Rivited panel surface measurement using photogrammetry

    NASA Technical Reports Server (NTRS)

    Merrick, W. D.; Lobb, V. B.; Lansing, F. L.; Stoller, F. W.

    1986-01-01

    Two riveted antenna panels on rings number 3 and 9 were removed from the 34m antenna at DSS-15, fixed in the leveled position and the surface was photographed indoors. The results from this pilot photogrammetric demonstration and diagnostics of panel surface contours, are presented. The photogrammetric network for each panel incorporated eight photographs, two from each of four camera stations and observed over 200 targets. The accuracy (1 sigma) of the XYZ coordinates for the error ellipsoids was + or - 0.013 mm (0.0005 inch). This level of precision relative to the object size corresponds roughly to 1 part in 250,000 which is superior to conventional dial sweep-arm template techniques by at least a factor of 4.

  4. 20. 'Erection Plan, Renewal of Bridge 210 C over Sacramento ...

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

    20. 'Erection Plan, Renewal of Bridge 210 C over Sacramento River near Tehama, Calif., 3 140'-0' S. T. Riveted Thru Truss Spans, 17'-9' C. to C. Trusses, 31'-0' C. To C. Chords. U.S.S. P. Co. Pacific Coast Dept., Order No. SF 604, Southern Pacific Co., Order No. 51168-P-38428, 1925 Specifications, Scale in. ft., American Bridge Co., Ambridge Plant, Dwgs. made at Ambridge No. 5 in charge of Reehl, Detailed by W.F.R., Date, Checked by L.A.E., Date 1/5/29, Fld. conn. chk. by ENN, Date 3/9/29, Order No. F5659, Sheet No. E3.' - Southern Pacific Railroad Shasta Route, Bridge No. 210.52, Milepost 210.52, Tehama, Tehama County, CA

  5. Low-Temperature Forming of Beta Titanium Alloys

    NASA Technical Reports Server (NTRS)

    Kaneko, R. S.; Woods, C. A.

    1983-01-01

    Low cost methods for titanium structural fabrication using advanced cold-formable beta alloys were investigated for application in a Mach 2.7 supersonic cruise vehicle. This work focuses on improving processing and structural efficiencies as compared with standard hot formed and riveted construction of alpha-beta alloy sheet structure. Mechanical property data and manufacturing parameters were developed for cold forming, brazing, welding, and processing Ti-15V-3Cr-3Sn-3Al sheet, and Ti-3Al-8V-6Cr-4Zr on a more limited basis. Cost and structural benefits were assessed through the fabrication and evaluation of large structural panels. The feasibility of increasing structural efficiency of beta titanium structure by selective reinforcement with metal matrix composite was also explored.

  6. In the path of destruction - eyewitness chronicles of Mount St. Helens

    USGS Publications Warehouse

    Waitt, Richard B.

    2015-01-01

    “The air had no oxygen, like being trapped underwater…I was being cremated, the pain unbearable.”-- Jim Scymanky“I was on my knees, my back to the hot wind. It blew me along, lifting my rear so I was up on my hands…It was hot but I didn’t feel burned—until I felt my ears curl.”—Mike HubbardA napping volcano blinked awake in March 1980. Two months later, the mountain roared. Author Richard Waitt was one of the first to arrive following the mountain’s early rumblings. A geologist with intimate knowledge of Mount St. Helens, Waitt delivers a detailed and accurate chronicle of events. The eruption story unfolds through unforgettable, riveting narratives—the heart of a masterful chronology that also delivers engrossing science, history, and journalism.

  7. Acoustic fatigue testing on different materials and skin-stringer elements

    NASA Astrophysics Data System (ADS)

    Koenig, Klaus

    1994-09-01

    Within a comparative study, 29 different coupons covering 8 different designs and 6 different materials were fatigued by an excitation of 30 g(exp 2)/Hz on a shaker. The selected designs and materials represent realistic alternatives of an aircraft surface structure. The investigation led to the following conclusion: (1) Besides classical aluminium, CFRP is the best material with regard to sonic fatigue. (2) Al/Li, ARALL and Al layer materials showed shorter life times than the classical Al. (3) The most striking improvement in design for the dimensions selected here was achieved with separate doublers between skin and stringer. (4) The modal damping found was most often smaller than the 1.7 percent of the critical as known from ESDU for Al. (5) Pure CFRP without rivets showed the smallest damping: 0.6 - 0.9 percent.

  8. Evolutionary suicide through a non-catastrophic bifurcation: adaptive dynamics of pathogens with frequency-dependent transmission.

    PubMed

    Boldin, Barbara; Kisdi, Éva

    2016-03-01

    Evolutionary suicide is a riveting phenomenon in which adaptive evolution drives a viable population to extinction. Gyllenberg and Parvinen (Bull Math Biol 63(5):981-993, 2001) showed that, in a wide class of deterministic population models, a discontinuous transition to extinction is a necessary condition for evolutionary suicide. An implicit assumption of their proof is that the invasion fitness of a rare strategy is well-defined also in the extinction state of the population. Epidemic models with frequency-dependent incidence, which are often used to model the spread of sexually transmitted infections or the dynamics of infectious diseases within herds, violate this assumption. In these models, evolutionary suicide can occur through a non-catastrophic bifurcation whereby pathogen adaptation leads to a continuous decline of host (and consequently pathogen) population size to zero. Evolutionary suicide of pathogens with frequency-dependent transmission can occur in two ways, with pathogen strains evolving either higher or lower virulence.

  9. Inspection of a Medieval Wood Sculpture Using Computer Tomography

    NASA Astrophysics Data System (ADS)

    Kapitany, K.; Somogyi, A.; Barsi, A.

    2016-06-01

    Computer tomography (CT) is an excellent technique for obtaining accurate 3D information about the human body. It allows to visualize the organs, bones and blood vessels, furthermore it enables to diagnose anomalies and diseases. Its spatial reconstruction capability supports other interesting applications, such as inspecting different, even valuable objects like ancient sculptures. Current paper presents a methodology of evaluating CT and video imagery through the example of investigating a wood Madonna with infant Jesus sculpture from the 14th century. The developed techniques extract the outer boundary of the statue, which has been triangulated to derive the surface model. The interior of the sculpture has also been revealed: the iron bolts and rivets as well as the woodworm holes can be mapped. By merging the interior and outer data (geometry and texture) interesting visualizations (perspective views, sections etc.) have been created.

  10. Development of an adhesively bonded beryllium propulsion structure for the Mariner Mars 1971 spacecraft

    NASA Technical Reports Server (NTRS)

    Stevens, J. H.; Layman, W. E.

    1972-01-01

    The design, testing, and fabrication of the support truss structure for the propulsion system of the Mariner 9 spacecraft are described. Support is provided by an 8.9-kg (19.5-lbm) truss assembly consisting of beryllium tubes adhesively bonded to magnesium end fittings. Beryllium was selected for the tubular struts in the truss because of its exceptionally high stiffness-to-weight ratio. Adhesive bonding, rather than riveting, was utilized to join the struts to the end fittings because of the low toughness (high notch sensitivity) of beryllium. Magnesium, used in the end fittings, resulted in a 50% weight saving over aluminum since geometric factors in the fitting design resulted in low stress areas where magnesium's lower density is a benefit.

  11. Book Review: Dangerous Neighbors: Volcanoes and Cities

    SciTech Connect

    Caporuscio, Florie Andre

    2013-01-01

    Here, Grant Heiken, a world-renowned volcanologist, has written a book based on his long history investigating volcanic hazards that is absolutely riveting. Eight of the ten chapters focus on the interplay between major metropolises and destructive volcanoes. The introductory chapter sets the stage for the remainder of the book. This chapter touches on various types of volcanic events; from Nyiragongo lava flows that disrupted the city of Goma, DRC, to debris flows from Nevado del Ruiz that killed 23,000 residents in Armero, Columbia, to the Eyjafjallajokull volcano in Iceland which spewed an ash column into the jet stream and disrupted air travel to 32 European countries for 6 days. Other issues weaved into the introduction are the social and political fallout when a predicted eruption does not occur (Soufriere de Guadeloupe), how hazard evaluation processes change, and why do major populations reside near high risk volcanoes.

  12. Narrating September 11: Race, Gender, and the Play of Cultural Identities

    PubMed Central

    Mattingly, Cheryl; Lawlor, Mary; Jacobs-Huey, Lanita

    2010-01-01

    This article considers the September 11 tragedy as an event that has created a powerful experience—an astonishing and unthinkable “breach” from the expected and routine—that has riveted the American public and provoked personal storytelling. September 11 and its aftermath have provided an occasion for rethinking and reworking cultural identity. We explore how September 11 and subsequent events have been experienced, constructed, and narrated by African American women, primarily from working-class and low-income backgrounds. These stories, and the commentaries and discussions that surround them, provide vehicles for these women to ponder what sort of social contexts they inhabit, within what sort of subject positions they are placed, and how these may be shifting in light of the attacks and America's “War on Terrorism. PMID:20706602

  13. Thermal performance evaluation of the Suncatcher SH-11 (liquid) solar collector

    NASA Technical Reports Server (NTRS)

    1980-01-01

    The procedures used and the results obtained during the evaluation test program on the Solar Unlimited, Inc., Suncatcher SH-11 (liquid) solar collector are presented. The flat-plate collector case assembly is made of .08 inch aluminum 3003 H14 riveted with fiberglass board insulation. The absorber consists of collared aluminum fins mechanically bonded to 3/8 inch copper tubing and coated with 3M Nextel black. Water is used as the working fluid. The glazing is made of a single glass, 1/8 inch water white, tempered and antireflective. The collector weight is 85 pounds with overall external dimensions of about 35.4 in x 82.0 in x 4.0 in. Thermal performance data on the Solar Unlimited Suncatcher SH-11 solar collector under simulated conditions were conducted using the MSFC Solar Simulator.

  14. An investigation of the aerodynamic characteristics of a new general aviation airfoil in flight

    NASA Technical Reports Server (NTRS)

    Gregorek, G. M.; Hoffmann, M. J.; Weislogel, G. S.

    1982-01-01

    A low speed airfoil, the GA(W)-2, - a 13% thickness to chord ratio airfoil was evaluated. The wing of a Beech Sundowner was modified at by adding balsa ribs and covered with aluminum skin, to alter the existing airfoil shape to that of the GA(W)-2 airfoil. The aircraft was flown in a flight test program that gathered wing surface pressures and wake data from which the lift drag, and pitching moment of the airfoil could be determined. After the base line performance of the airfoil was measured, the drag due to surface irregularities such as steps, rivets and surface waviness was determined. The potential reduction of drag through the use of surface coatings such as KAPTON was also investigated.

  15. Low Temperature SQUID for NDE Applications

    NASA Technical Reports Server (NTRS)

    Wincheski, Buzz (Technical Monitor); Selim, Raouf

    2003-01-01

    We have developed a low temperature SuperConducting Quantum Interference Device - SQUID measurement system for detection of defects deep under the surface of aluminum structures using eddy current techniques. The system uses a two dimensional planar inducer with two different excitation frequencies to induce a current in the sample. We have developed a data analysis software program that enabled us to distinguish between round defects (holes), straight defects (slots) and slots close to holes simulating cracks starting from rivets in aluminum structures. We were able to detect defects that are 8mm below the surface. We have also measured the change in phase of the detected signal as a function of depth of the defect. This relationship can be used to determine the depth of hidden flaws. Using this analysis software with the high temperature SQUID system at NASA Langley we were able to detect slots close to holes in layered aluminum sample.

  16. Powered protrusion cutter

    DOEpatents

    Bzorgi, Fariborz M.

    2010-03-09

    An apparatus for clipping a protrusion of material is provided. The protrusion may, for example, be a bolt head, a nut, a rivet, a weld bead, or a temporary assembly alignment tab protruding from a substrate surface of assembled components. The apparatus typically includes a cleaver having a cleaving edge and a cutting blade having a cutting edge. Generally, a mounting structure configured to confine the cleaver and the cutting blade and permit a range of relative movement between the cleaving edge and the cutting edge is provided. Also typically included is a power device coupled to the cutting blade. The power device is configured to move the cutting edge toward the cleaving edge. In some embodiments the power device is activated by a momentary switch. A retraction device is also generally provided, where the retraction device is configured to move the cutting edge away from the cleaving edge.

  17. Device for cutting protrusions

    DOEpatents

    Bzorgi, Fariborz M.

    2011-07-05

    An apparatus for clipping a protrusion of material is provided. The protrusion may, for example, be a bolt head, a nut, a rivet, a weld bead, or a temporary assembly alignment tab protruding from a substrate surface of assembled components. The apparatus typically includes a cleaver having a cleaving edge and a cutting blade having a cutting edge. Generally, a mounting structure configured to confine the cleaver and the cutting blade and permit a range of relative movement between the cleaving edge and the cutting edge is provided. Also typically included is a power device coupled to the cutting blade. The power device is configured to move the cutting edge toward the cleaving edge. In some embodiments the power device is activated by a momentary switch. A retraction device is also generally provided, where the retraction device is configured to move the cutting edge away from the cleaving edge.

  18. Statistical multi-site fatigue damage analysis model

    NASA Astrophysics Data System (ADS)

    Wang, G. S.

    1995-02-01

    A statistical model has been developed to evaluate fatigue damage at multi-sites in complex joints based on coupon test data and fracture mechanics methods. The model is similar to the USAF model, but modified by introducing a failure criterion and a probability of fatal crack occurrence to account for the multiple site damage phenomenon. The involvement of NDI techniques has been included in the model which can be used to evaluate the structural reliability, the detectability of fatigue damage (cracks), and the risk of failure based on NDI results taken from samples. A practical example is provided for rivet fasteners and bolted fasteners. It is shown that the model can be used even if it is based on conventional S-N coupon experiments should further fractographic inspections be made for cracks on the broken surfaces of specimens.

  19. Magnesium alloy applications in automotive structures

    NASA Astrophysics Data System (ADS)

    Easton, Mark; Beer, Aiden; Barnett, Matthew; Davies, Chris; Dunlop, Gordon; Durandet, Yvonne; Blacket, Stuart; Hilditch, Tim; Beggs, Peter

    2008-11-01

    The use of magnesium alloys in structural applications has great potential for the lightweighting of transportation vehicles. Research within the CAST Cooperative Research Centre has tackled some of the important issues related to the use of magnesium in structural applications. To this end, a new alloy with extrudability and properties similar to 6000 series aluminum alloys has been developed. Furthermore, a method of laser heating magnesium alloys before self-piercing riveting has enabled high-integrity joining between magnesium components or between magnesium and dissimilar metals. In this paper, new technologies and improved understanding of the deformation behavior of wrought magnesium alloys are discussed in light of key metallurgical features such as alloy composition, grain size, and work hardening rate.

  20. Evaluation of Pressurization Fatigue Life of 1441 Al-li Fuselage Panel

    NASA Technical Reports Server (NTRS)

    Bird, R. Keith; Dicus, Dennis I.; Fridlyander, Joseph; Davydov, Valentin

    1999-01-01

    A study was conducted to evaluate the pressurization fatigue life of fuselage panels with skins fabricated from 1441 Al-Li, an attractive new Russian alloy. The study indicated that 1441 Al-Li has several advantages over conventional aluminum fuselage skin alloy with respect to fatigue behavior. Smooth 1441 Al-Li sheet specimens exhibited a fatigue endurance limit similar to that for 1163 Al (Russian version of 2024 Al) sheet. Notched 1441 Al-Li sheet specimens exhibited greater fatigue strength and longer fatigue life than 1163 Al. In addition, Tu-204 fuselage panels fabricated by Tupolev Design Bureau using Al-Li skin and ring frames with riveted 7000-series aluminum stiffeners had longer pressurization fatigue lives than did panels constructed from conventional aluminum alloys. Taking into account the lower density of this alloy, the results suggest that 1441 Al-Li has the potential to improve fuselage performance while decreasing structural weight.

  1. Intrinsic manufacture of hollow thermoplastic composite/metal structures

    NASA Astrophysics Data System (ADS)

    Barfuss, Daniel; Grützner, Raik; Garthaus, Christian; Gude, Maik; Müller, Roland; Langrebe, Dirk

    2016-10-01

    In contrast to common and classical joining technologies for composite/metal hybrid structures such as bonding and riveting, profile and contour joints offer a promising potential for novel lightweight hybrid structures. First and foremost, joining systems with a form closure function enable to pass very high loads into rod- and tube-shaped fibre reinforced structures and achieve high degrees of material utilization for the composite part. This paper demonstrates the theoretical and technological principals for a resource efficient design and production of highly loaded thermoplastic composite profile structures with integrated metallic load introduction elements and a multi scale form closure. The hybrid structures are produced in an integral blow moulding process in which a braided tape-preform is simultaneously consolidated and formed into the metallic load introduction element. These metallic load introduction elements are manufactured in a two-stage process of external and internal hydroforming, after forming simulations have assured process stability for consistent quality.

  2. Novel method for joining CFRP to aluminium

    NASA Astrophysics Data System (ADS)

    Möller, F.; Thomy, C.; Vollertsen, F.; Schiebel, P.; Hoffmeister, C.; Herrmann, A. S.

    The current state of the art in joining of carbon-fibre reinforced composites (CFRP) to metals such as aluminium is - for the case of aircraft structures, e.g.- riveting or bolting. However, to reduce structural weight and improve structural performance, integral, load-bearing aluminium-CFRP-structures are desirable. To produce such structures, a novel joint configuration together with an appropriate thermal, laser-based joining process is suggested by the authors. In this paper, the joint configuration (based on CFRP-Ti-aluminium joints) and the laser beam conduction welding process will be presented, and first specimens obtained will be discussed with respect to their properties. It will be shown that the novel approach is in principle suitable to produce load-bearing CFRP-aluminium structures.

  3. Characterization of Nitinol Laser-Weld Joints by Nondestructive Testing

    NASA Astrophysics Data System (ADS)

    Wohlschlögel, Markus; Gläßel, Gunter; Sanchez, Daniela; Schüßler, Andreas; Dillenz, Alexander; Saal, David; Mayr, Peter

    2015-12-01

    Joining technology is an integral part of today's Nitinol medical device manufacturing. Besides crimping and riveting, laser welding is often applied to join components made from Nitinol to Nitinol, as well as Nitinol components to dissimilar materials. Other Nitinol joining techniques include adhesive bonding, soldering, and brazing. Typically, the performance of joints is assessed by destructive mechanical testing, on a process validation base. In this study, a nondestructive testing method—photothermal radiometry—is applied to characterize small Nitinol laser-weld joints used to connect two wire ends via a sleeve. Two different wire diameters are investigated. Effective joint connection cross sections are visualized using metallography techniques. Results of the nondestructive testing are correlated to data from destructive torsion testing, where the maximum torque at fracture is evaluated for the same joints and criteria for the differentiation of good and poor laser-welding quality by nondestructive testing are established.

  4. Measurements of fuselage skin strains and displacements near a longitudinal lap joint in a pressurized aircraft

    NASA Technical Reports Server (NTRS)

    Phillips, Edward P.; Britt, Vicki O.

    1991-01-01

    Strains and displacements in a small area near a longitudinal lap joint in the fuselage skin of a B737 aircraft were measured during a pressurization cycle to a differential pressure of 6.2 psi while the aircraft was on the ground. It was found that hoop strains were higher than longitudinal strains at each location; membrane strains in the unreinforced skin were higher than in the joint; membrane strains in the hoop direction, as well as radial displacements, tended to be highest at the mid-bay location between skin reinforcements; significant bending in the hoop direction occurred in the joint and in the skin near the joint, and the bending was unsymmetrically distributed about the stringer at the middle of the joint; and radial displacements were unsymmetrically distributed across the lap joint. The interpretation of the strain gage data for locations on the bonded and riveted lap joint assumed that the joint did not contain disbonded areas.

  5. Migrants, Manpower and Math in the Coming Europe

    PubMed Central

    Evans, Robert G.

    2015-01-01

    “A dead child” said Stalin “is a tragedy. Two million are a statistic.” A single photograph of a beach riveted world attention, converting Syrian refugees from statistics to tragedy. But the statistics remain. Three Canadian columnists have offered contrasting interpretations. Eric Reguly argues that a static and aging Europe needs more manpower to sustain its economy. Margaret Wente, however, observes the failure of integration of migrants in Sweden. Migrants are drawn by open borders and a generous welfare state, but do not fit an advanced, high-skill economy. Gwynne Dyer notes that current inflows, IF evenly distributed, are a tiny proportion of the overall European Union. But economic migrants from Africa are a much larger issue. Their numbers are effectively inexhaustible. PMID:26742112

  6. Book Review: Dangerous Neighbors: Volcanoes and Cities

    DOE PAGES

    Caporuscio, Florie Andre

    2013-01-01

    Here, Grant Heiken, a world-renowned volcanologist, has written a book based on his long history investigating volcanic hazards that is absolutely riveting. Eight of the ten chapters focus on the interplay between major metropolises and destructive volcanoes. The introductory chapter sets the stage for the remainder of the book. This chapter touches on various types of volcanic events; from Nyiragongo lava flows that disrupted the city of Goma, DRC, to debris flows from Nevado del Ruiz that killed 23,000 residents in Armero, Columbia, to the Eyjafjallajokull volcano in Iceland which spewed an ash column into the jet stream and disruptedmore » air travel to 32 European countries for 6 days. Other issues weaved into the introduction are the social and political fallout when a predicted eruption does not occur (Soufriere de Guadeloupe), how hazard evaluation processes change, and why do major populations reside near high risk volcanoes.« less

  7. Evaluation of Local Residual Stress Distribution of Stator Core in Rotating Machine

    NASA Astrophysics Data System (ADS)

    Kai, Yuichiro; Tsuchida, Yuji; Todaka, Takashi; Enokizono, Masato

    It is well known that magnetic properties deteriorate in constructed cores due to conditions stressed by riveting and welding during manufacturing process, punching and sharing in cutting process of the electrical steel sheets and so on. Therefore, it is important to know the relationships between the stress and magnetic property of the electrical steel in order to design the electrical machinery. In this paper, the local residual stress distribution on the cross section of the stator core in a rotating machine is measured with a X-ray stress measurement device. As the result, the difference of the residual stress distribution of each component is obtained in the teeth and core back of the stator core. In addition, we estimated the deterioration of the magnetic property in the teeth region. It was clarified that the magnetic properties of the electrical steel sheet is deteriorated due to the residual stress.

  8. The evolution of small payload carrier systems

    NASA Technical Reports Server (NTRS)

    Breaux, C. G.

    1984-01-01

    The design of a bridge-like structure to span the Space Shuttle cargo bay but occupy only 3 feet of its length is discussed. The new structure was named the Missions Peculiar Equipment Support Structure (MPESS). The basic design requirements were as follows: to serve as support structure for small number of experiments; to occupy the minimal length of cargo bay; to have a standard interface hole pattern; to provide support at an elevated position; to employ standard Spacelab pallet trunnion; and to ensure natural frequency between the STS liftoff and landing frequency. The bridge-like structure is a riveted and bolted truss with machind end fittings which interface with the Spacelab trunnions. The structure is fabricated from aluminum alloy and assembled with stainless steel fasteners.

  9. The effect of oblique angle of sound incidence, realistic edge conditions, curvature and in-plane panel stresses on the noise reduction characteristics of general aviation type panels

    NASA Technical Reports Server (NTRS)

    Grosveld, F.; Lameris, J.; Dunn, D.

    1979-01-01

    Experiments and a theoretical analysis were conducted to predict the noise reduction of inclined and curved panels. These predictions are compared to the experimental results with reasonable agreement between theory and experiment for panels under an oblique angle of sound incidence. Theoretical as well as experimental results indicate a big increase in noise reduction when a flat test panel is curved. Further curving the panel slightly decreases the noise reduction. Riveted flat panels are shown to give a higher noise reduction in the stiffness-controlled frequency region, while bonded panels are superior in this region when the test panel is curved. Experimentally measured noise reduction characteristics of flat aluminum panels with uniaxial in-plane stresses are presented and discussed. These test results indicate an important improvement in the noise reduction of these panels in the frequency range below the fundamental panel/cavity frequency.

  10. Structural parameters that influence the noise reduction characteristics of typical general aviation materials

    NASA Technical Reports Server (NTRS)

    Roskam, J.; Grosveld, F.

    1980-01-01

    Effect of panel curvature and oblique angle of sound incidence on noise reduction characteristics of an aluminum panel are experimentally investigated. Panel curvature results show significant increase in stiffness with comparable decrease of sound transmission through the panel in the frequency region below the panel/cavity resonance frequency. Noise reduction data have been achieved for aluminum panels with clamped, bonded and riveted edge conditions. These edge conditions are shown to influence noise reduction characteristics of aluminum panels. Experimentally measured noise reduction characteristics of flat aluminum panels with uniaxial and biaxial in-plane stresses are presented and discussed. Results indicate important improvement in noise reduction of these panels in the frequency range below the fundamental panel/cavity resonance frequency.

  11. Study of the damping characteristics of general aviation aircraft panels and development of computer programs to calculate the effectiveness of interior noise control treatment, part 1

    NASA Technical Reports Server (NTRS)

    Navaneethan, R.; Hunt, J.; Quayle, B.

    1982-01-01

    Tests were carried out on 20 inch x 20 inch panels at different test conditions using free-free panels, clamped panels, and panels as installed in the KU-FRL acoustic test facility. Tests with free-free panels verified the basic equipment set-up and test procedure. They also provided a basis for comparison. The results indicate that the effect of installed panels is to increase the damping ratio at the same frequency. However, a direct comparison is not possible, as the fundamental frequency of a free-free panel differs from the resonance frequency of the panel when installed. The damping values of panels installed in the test facility are closer to the damping values obtained with fixed-fixed panels. Effects of damping tape, stiffeners, and bonded and riveted edged conditions were also investigated. Progress in the development of a simple interior noise level control program is reported.

  12. Constraining new physics with collider measurements of Standard Model signatures

    NASA Astrophysics Data System (ADS)

    Butterworth, Jonathan M.; Grellscheid, David; Krämer, Michael; Sarrazin, Björn; Yallup, David

    2017-03-01

    A new method providing general consistency constraints for Beyond-the-Standard-Model (BSM) theories, using measurements at particle colliders, is presented. The method, `Constraints On New Theories Using Rivet', Contur, exploits the fact that particle-level differential measurements made in fiducial regions of phase-space have a high degree of model-independence. These measurements can therefore be compared to BSM physics implemented in Monte Carlo generators in a very generic way, allowing a wider array of final states to be considered than is typically the case. The Contur approach should be seen as complementary to the discovery potential of direct searches, being designed to eliminate inconsistent BSM proposals in a context where many (but perhaps not all) measurements are consistent with the Standard Model. We demonstrate, using a competitive simplified dark matter model, the power of this approach. The Contur method is highly scaleable to other models and future measurements.

  13. Migrants, Manpower and Math in the Coming Europe.

    PubMed

    Evans, Robert G

    2015-11-01

    "A dead child" said stalin "is a tragedy. Two million are a statistic." A single photograph of a beach riveted world attention, converting syrian refugees from statistics to tragedy. But the statistics remain. Three Canadian columnists have offered contrasting interpretations. Eric Reguly argues that a static and aging Europe needs more manpower to sustain its economy. Margaret Wente, however, observes the failure of integration of migrants in Sweden. Migrants are drawn by open borders and a generous welfare state, but do not fit an advanced, high-skill economy. Gwynne Dyer notes that current inflows, IF evenly distributed, are a tiny proportion of the overall European Union. But economic migrants from Africa are a much larger issue. Their numbers are effectively inexhaustible.

  14. Development of an improved performance SiGe unicouple

    SciTech Connect

    Nakahara, J.F.; Franklin, B.; DeFillipo, L.E.

    1995-01-20

    A two-step diffusion bonding process was developed such that the p-type material is bonded to the SiMo hot shoe first at 1594 K followed by the lower melting point n-type material between 1518 and 1520 K. Standard procedures were used to silicon nitride coat the thermoelectric pellets and to attach the cold side CTE transition and heat rejection components to produce unicouples. Two unicouples successfully withstood simulated rivet operations as would be experienced in the fabrication of a Radioisotope Thermoelectric Generator (RTG) converter to verify the integrity of the tungsten cold shoe to thermoelectric material interface. The performance of these unicouples will be further evaluated in an 18-couple test module. {copyright}American Institute of Physics 1995

  15. Self-Calibrating Ultrasonic Methods for In-Situ Monitoring of Fatigue Crack Progression

    SciTech Connect

    Michaels, J.E.; Mi, B.; Cobb, A.C.; Michaels, T.E.; Stobbe, D.M.

    2005-04-09

    Ultrasonic sensors permanently affixed to aluminum coupons are used to monitor progression of damage during fatigue testing with the long term goal of structural health monitoring for diagnostics and prognostics. Necessary for success are proper design of the ultrasonic testing methods, robust transducer mounting techniques, and real-time signal processing for determining the state of the structure. It is also highly desirable for the overall system to be self-calibrating with built-in diagnostics in order to detect and compensate for sensor degradation or failure. Self-calibrating ultrasonic techniques are applied for monitoring of cracks initiating and propagating from the inaccessible inner diameters of rivet holes where the transducers are mounted on the accessible specimen surface. Angle beam ultrasonic methods are utilized that are suitable for detecting small defects in critical local regions of high stress. Results are presented for aluminum coupons subjected to low cycle fatigue and demonstrate ultrasonic tracking of crack growth.

  16. 18. VIEW SOUTHWEST OF 450 HP TURBINE INSTALLATION IN BASEMENT ...

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

    18. VIEW SOUTHWEST OF 450 HP TURBINE INSTALLATION IN BASEMENT OF GRANITEVILLE MILL. MAIN FEATURE OF THE PHOTOGRAPH IS THE PENSTOCK CONDUCTING WATER TO THE TURBINE IN THE BACKGROUND. THE PENSTOCK IS OF RIVETED IRON CONSTRUCTION AND REPLACED A WOOD PENSTOCK IN 1882. THE COVERED OPENING IN THE CENTER OF THE PHOTOGRAPH ORIGINALLY CONNECTED TO A STANDPIPE WHICH EXITED VERTICALLY THROUGH THE MILL. THE STANDPIPE MODERATED WATER PRESSURE AND SERVED AS A SAFETY FEATURE IN THE EVENT THE TURBINE GATES WERE RAPIDLY CLOSED. (IF LOAD IN THE MILL WERE SUDDENLY STOPPED-SAY AT QUITTING TIME-THE GATES WOULD SHUT DOWN FLOW TO THE TURBINE. THE STANDPIPE OFFERED A PLACE FOR THE WATER, RAPIDLY MOVING THROUGH THE PENSTOCK, TO ESCAPE. IN A SHUT-DOWN SITUATION WATER WOULD ... - Graniteville Mill, Marshall Street, Graniteville, Aiken County, SC

  17. Self-Calibrating Ultrasonic Methods for In-Situ Monitoring of Fatigue Crack Progression

    NASA Astrophysics Data System (ADS)

    Michaels, J. E.; Michaels, T. E.; Mi, B.; Cobb, A. C.; Stobbe, D. M.

    2005-04-01

    Ultrasonic sensors permanently affixed to aluminum coupons are used to monitor progression of damage during fatigue testing with the long term goal of structural health monitoring for diagnostics and prognostics. Necessary for success are proper design of the ultrasonic testing methods, robust transducer mounting techniques, and real-time signal processing for determining the state of the structure. It is also highly desirable for the overall system to be self-calibrating with built-in diagnostics in order to detect and compensate for sensor degradation or failure. Self-calibrating ultrasonic techniques are applied for monitoring of cracks initiating and propagating from the inaccessible inner diameters of rivet holes where the transducers are mounted on the accessible specimen surface. Angle beam ultrasonic methods are utilized that are suitable for detecting small defects in critical local regions of high stress. Results are presented for aluminum coupons subjected to low cycle fatigue and demonstrate ultrasonic tracking of crack growth.

  18. NASTRAN DMAP Fuzzy Structures Analysis: Summary of Research

    NASA Technical Reports Server (NTRS)

    Sparrow, Victor W.

    2001-01-01

    The main proposed tasks of Cooperative Agreement NCC1-382 were: (1) developing MSC/NASTRAN DMAP language scripts to implement the Soize fuzzy structures approach for modeling the dynamics of complex structures; (2) benchmarking the results of the new code to those for a cantilevered beam in the literature; and (3) testing and validating the new code by comparing the fuzzy structures results to NASA Langley experimental and conventional finite element results for two model test structures representative of aircraft fuselage sidewall construction: (A) a small aluminum test panel (SLP, single longeron panel) with a single longitudinal stringer attached with bolts; and (B) a 47 by 72 inch flat aluminum fuselage panel (AFP, aluminum fuselage panel) including six longitudinal stringers and four frame stiffeners attached with rivets.

  19. The psychocultural roots of genocide. Legitimacy and crisis in Rwanda.

    PubMed

    Smith, D N

    1998-07-01

    In April 1994, the small east African nation of Rwanda became the site of one of the most violent episodes of the 20th century. Over the course of just 100 days, an embattled authoritarian state organized the slaughter of at least 850,000 Rwandans. Briefly, worldwide attention was riveted. But clichés about "age-old tribal hatreds" soon dominated discussion, conveying the impression that this was simply the latest episode in an unending cycle of violence. The truth, however, is quite different. The April genocide was in many ways unique. It was neither tribal nor age-old, and it is hardly fated to recur. Indeed, the author's premise is that if this genocide is grasped in all its psychocultural novelty and complexity, a point of Archimedean leverage can be found for interventions to avert tragedies in the future.

  20. Integral Manufacturing of Composite Skin-Stringer Assembly and Their Stability Analyses

    NASA Astrophysics Data System (ADS)

    Mahfuz, Hassan; Majumdar, Prasun; Saha, Mrinal; Shamery, Frederick; Jeelani, Shaik

    2004-05-01

    Stiffened composite constructions are increasingly being used in the primary structures of aircraft. One key component in these structures is the assembly between the skin and the stringer. The purpose of the stringers sandwiched between two separate layers of skin is to provide structural integrity to a relatively weak skin-structure. Current practice is to fabricate the skin and the stringer separately, assemble them with adhesively bonded joints, and then co-cure the entire assembly in an autoclave. However, the reliability of the joint manufactured in this fashion is not dependable and hence requires riveting of the skin with the stringer by hundreds of mechanical fasteners. Although the mechanical fastener improves the joint reliability, it certainly increases the weight and reduces the strength of the structure by introducing stress concentration points around the rivet holes. In order to eliminate these disadvantages, an innovative low cost manufacturing technique has been developed. The technique utilizes the vacuum assisted resin transfer molding (VARTM) process to co-inject both the skin and the stringer in one integral step. Furthermore, the skin and the stringer are now part of one continuous fabric preform which by default eliminates any adhesive bonding. Several skin-stringer assemblies with plain weave carbon fabric and SC-15 epoxy resin have been manufactured following this procedure. Stability of the manufactured skin-stringer assembly has been investigated experimentally. The extensive analysis focused on the determination of the critical load corresponding to the instability of the structure, failure load and study of the failure mechanisms. Details of manufacturing procedures and experimental investigations are presented in the paper.

  1. In situ repair welding of steam turbine shroud for replacing a cracked blade

    NASA Astrophysics Data System (ADS)

    Albert, S. K.; Das, C. R.; Ramasubbu, V.; Bhaduri, A. K.; Ray, S. K.; Raj, Baldev

    2002-06-01

    A root-cracked blade in a high-pressure steam turbine of a nuclear power plant had to be replaced with a new blade by cutting the shroud to remove the cracked blade. This necessitated in situ welding of a new shroud piece with the existing shroud after the blade replacement. The in situ welding of the shroud, a 12% Cr martensitic stainless steel with tempered martensite microstructure, was carried out using gastungsten arc welding and 316L austenitic stainless steel filler metal followed by localized postweld heat treatment at 873 K for 1 h using a specially designed electrical resistance-heating furnace. Mock-up trials were carried out to ensure that sound welds could be made under the constraints present during the in situ repair welding operation. In situ metallography of the repair weld after postweld heat treatment confirmed the adequate tempering of the martensitic structure in the heat-affected zone. Metallurgical investigations carried out in the laboratory on a shroud test-piece that had been welded using the same procedure as employed in the field confirmed the success of the in situ repair operation. The alternate option available was replacing the cracked blade and the shroud piece to which it is riveted with a new one, reducing the height of all the blades attached to the shroud by machining, riveting the blades with reduced height to the new shroud, and, finally, dynamic balancing of the entire turbine after completion of the repair. This option is both time-consuming and expensive. Hence, the successful completion of this repair welding resulted in enormous savings both in terms of reducing the downtime of the plant and the cost of the repair. The turbine has been put back into service and has been operating satisfactorily since December 2000.

  2. Dual-band infrared (DBIR) imaging inspections of Boeing 737 and KC-135 aircraft panels

    SciTech Connect

    Del Grande, N.K.; Dolan, K.W.; Durbin, P.F.; Gorvad, M.R.; Shapiro, A.B.

    1993-08-27

    We apply dual-band infrared (DBIR) imaging as a dynamic thermal tomography tool for wide area inspection of a Boeing 737 aircraft, and several Boeing KC-135 aircraft panels. Our analyses are discussed in this report. After flash-heating the aircraft skin, we record synchronized DBIR images every 40 ms, from onset to 8 seconds after the heat flash. We analyze selective DBIR image ratios which enhance surface temperature contrast and remove surface-emissivity clutter (from dirt, dents, tape, markings, ink, sealants, uneven paint, paint stripper, exposed metal and roughness variations). The Boeing 737 and KC-135 aircraft fuselage panels have varying percent thickness losses from corrosion. We established the correlation of percent thickness loss with surface temperature rise (above ambient) for a partially corroded F-18 wing box structure and several aluminum reference panels. Based on this correlation, lap splice temperatures rise 1{degrees}C per 24 {plus_minus} 5 % material loss at 0.4 s after the heat flash. We show tables, charts and temperature maps of typical lap splice material losses for the riveted (and bonded) Boeing 737, and the riveted (but unbonded) Boeing KC-135. We map the fuselage composite thermal inertia, based on the (inverse) slope of the surface temperature versus inverse square root of time. Composite thermal inertia maps characterize shallow skin defects within the lap splice at early times (<0.3 s) and deeper skin defects within the lap splice at late times (>0.4 s). Late time composite thermal inertia maps depict where corrosion-related thickness losses occur. Lap splice sites on a typical Boeing KC-135 panel with low composite thermal inertia values had high skin-thickness losses from corrosion.

  3. Dynamic thermal tomography for nondestructive inspection of aging aircraft

    SciTech Connect

    Del Grande, N.K.; Dolan, K.W.; Durbin, P.F.; Gorvad, M.R.; Shapiro, A.B.

    1993-11-01

    The authors apply dual-band infrared (DBIR) imaging as a dynamic thermal tomography tool for wide area inspection of a Boeing 737 aircraft and several Boeing KC-135 aircraft panels. The analyses are discussed in this report. After flash-heating the aircraft skin, they record synchronized DBIR images every 40 ms, from onset to 8 seconds after the heat flash. They analyze selective DBIR image ratios which enhance surface temperature contrast and remove surface-emissivity clutter. The Boeing 737 and KC-135 aircraft fuselage panels have varying percent thickness losses from corrosion. They established the correlation of percent thickness loss with surface temperature rise (above ambient) for a partially corroded F-18 wing box structure and several aluminum plates which had 6 to 60% thickness losses at milled flat-bottom hole sites. Based on this correlation, lap splice temperatures rise 1C per 24 {plus_minus} 5% material loss at 0.4 s after the heat flash. They tabulate and map corrosion-related percent thickness loss effects for the riveted Boeing 737, and the riveted Boeing KKC-135. They map the fuselage composite thermal inertia, based on the (inverse) slope of the surface temperature versus inverse square root of time. Composite thermal inertia maps characterized shallow skin defects within the lap splice at early times (< 0.3 s) and deeper skin defects within the lap splice at late times (> 0.4 s). Late time composite thermal inertia maps depict where corrosion-related thickness losses occur (e.g., on the inside of the Boeing 737 lap splice, beneath the galley and the latrine). Lap splice sites on a typical Boeing KC-135 panel with low composite thermal inertia values had high skin-thickness losses from corrosion.

  4. Transverse Reinforcement of Adhesive Joints

    NASA Astrophysics Data System (ADS)

    Sapozhnikov, S.; Shakirov, A.

    2015-05-01

    The shear of single-lap adhesive joints causes significant peel stresses in the adhesive layer, which is a particularly urgent problem for low-modulus polyurethane compositions. An experimental and computational analysis of various methods for increasing the load-bearing capacity of the joints by their strengthening with metallic z-elements was carried out. This strengthening hinders their delamination by the action of peel stresses, which allows one to reduce the overall dimensions and weight of adhesive joints. Two main strengthening methods were considered: with steel tapping screws (of diameter 2.5 mm) and blind aluminum rivets (of diameter 4.0 mm). The peculiarity of the strengthening lies in the fact that z-elements of minimum available diameter were used for reducing the effect of stress concentrations on the strength of the joints. The test of specimens for each type of strengthening showed an average increase in the ultimate load by 40% for the threaded reinforcements and by 10% for the rivets. During an analysis of stress state of the joints by the FEM, the nonlinear behavior of constituent materials and stress concentration in the region of reinforcing elements were taken into account. The mechanical properties of the adhesive layer and the GFRP covering were determined in separate experiments. The analysis showed that the weight of the reinforced adhesive joints could be lowered by 20-25% relative to that of unreinforced ones without reducing their load-bearing capacity. An additional effect caused by using the threaded reinforcing elements was a more than threefold increase in their rigidity as compared with that of analogous nonreinforced ones.

  5. Probabilistic Aspects of the Growth and Detection of Fatigue Cracks

    NASA Astrophysics Data System (ADS)

    Cohen, Moshe L.

    For engineering structures, fatigue, and more specifically fatigue life prediction, is a problem of great interest. The first part of this dissertation focuses on the importance of probabilistic methods in structural health management in general, and how they can be applied to fatigue failure prognosis. Paris' law, using measured values of the parameters in the law, has been used to forecast fatigue crack growth from an assumed initial probability distribution of crack lengths, represented by a truncated lognormal distribution. The evolution of this distribution with the number of cycles has been determined, and the probability of the existence of a crack larger than an undesirable value, but smaller than the value where failure may occur, has been calculated. In addition, inspections have been modeled using three typical probability of detection curves, and the effect of an inspection has been evaluated. The probability of detection concept has also been extended using a Bayesian approach to include the effect of the number of elapsed cycles and the stress range of each cycle. All statistics considered in this dissertation have been evaluated for a surface-breaking crack in a half-space and a cracked rivet hole in a lap joint, both under cyclic tensile loading. The second part of this dissertation focuses on an aspect of the diagnosis of fatigue cracks. The acoustic emission from fatigue crack growth has been calculated using the reciprocity relation, again for a surface-breaking crack in a half-space and a cracked rivet hole in a lap joint. This result, which is a stochastic quantity because the amount of crack growth is stochastic, is used to calculate the probability of detection of an acoustic wave emitted by the crack growth for these cases.

  6. Analysis of fretting fatigue in aircraft structures: Stresses, stress intensity factors, and life predictions

    NASA Astrophysics Data System (ADS)

    McVeigh, Pamela Alison

    Clamped contacts subjected to cyclic loading are prone to fretting fatigue, a mechanism of crack nucleation and propagation. In aircraft, fretting fatigue occurs at the rivet/hole interface on the fuselage skin and at the dovetail joint in engine hardware where disk and blade meet. The ability to predict the lives of such components would be a great aid in preventing failures. Finite element models appropriate for the calculation of fretting fatigue stresses and stress intensity factors are developed for two different contact geometries. In addition, several less computationally expensive numerical methods are also studied. Agreement between the various solutions is good. A severe increase in the mode I stress intensity factor near the surface is discovered in both geometries. Mode II stress intensity factors are also detailed, illustrating the complex non-proportional loading of fretting-induced cracks. A comparison is made between results obtained from actual surface profiles and those generated from prescribed surface profiles; the differences are significant. Equivalent initial flaw sizes are calculated for two different metals using an approach which ignores the effect of mode II stress intensity factors. Life predictions based on the equivalent initial flaw size approach are found to agree reasonably well with those measured in the laboratory for contact geometries similar to the rivet/hole interface. More data is needed before a judgment can be made about life correlations for the dovetail joint contact geometry. The analysis methods described throughout can be easily implemented and integrated into a system aimed at designing against fretting fatigue.

  7. Performance analysis of bonded composite doublers on aircraft structures

    SciTech Connect

    Roach, D.

    1995-08-01

    Researchers contend that composite repairs (or structural reinforcement doublers) offer numerous advantages over metallic patches including corrosion resistance, light weight, high strength, elimination of rivets, and time savings in installation. Their use in commercial aviation has been stifled by uncertainties surrounding their application, subsequent inspection and long-term endurance. The process of repairing or reinforcing airplane structures is time consuming and the design is dependent upon an accompanying stress and fatigue analysis. A repair that is too stiff may result in a loss of fatigue life, continued growth of the crack being repaired, and the initiation of a new flaw in the undesirable high stress field around the patch. Uncertainties in load spectrums used to design repairs exacerbates these problems as does the use of rivets to apply conventional doublers. Many of these repair or structural reinforcement difficulties can be addressed through the use of composite doublers. Primary among unknown entities are the effects of non-optimum installations and the certification of adequate inspection procedures. This paper presents on overview of a program intended to introduce composite doubler technology to the US commercial aircraft fleet. In this project, a specific composite application has been chosen on an L-1011 aircraft in order to focus the tasks on application and operation issues. Through the use of laboratory test structures and flight demonstrations on an in-service L-1011 airplane, this study is investigating composite doubler design, fabrication, installation, structural integrity, and non-destructive evaluation. In addition to providing an overview of the L-1011 project, this paper focuses on a series of fatigue and strength tests which have been conducted in order to study the damage tolerance of composite doublers. Test results to-date are presented.

  8. Mutual Inductance Problem for a System Consisting of a Current Sheet and a Thin Metal Plate

    NASA Technical Reports Server (NTRS)

    Fulton, J. P.; Wincheski, B.; Nath, S.; Namkung, M.

    1993-01-01

    Rapid inspection of aircraft structures for flaws is of vital importance to the commercial and defense aircraft industry. In particular, inspecting thin aluminum structures for flaws is the focus of a large scale R&D effort in the nondestructive evaluation (NDE) community. Traditional eddy current methods used today are effective, but require long inspection times. New electromagnetic techniques which monitor the normal component of the magnetic field above a sample due to a sheet of current as the excitation, seem to be promising. This paper is an attempt to understand and analyze the magnetic field distribution due to a current sheet above an aluminum test sample. A simple theoretical model, coupled with a two dimensional finite element model (FEM) and experimental data will be presented in the next few sections. A current sheet above a conducting sample generates eddy currents in the material, while a sensor above the current sheet or in between the two plates monitors the normal component of the magnetic field. A rivet or a surface flaw near a rivet in an aircraft aluminum skin will disturb the magnetic field, which is imaged by the sensor. Initial results showed a strong dependence of the flaw induced normal magnetic field strength on the thickness and conductivity of the current-sheet that could not be accounted for by skin depth attenuation alone. It was believed that the eddy current imaging method explained the dependence of the thickness and conductivity of the flaw induced normal magnetic field. Further investigation, suggested the complexity associated with the mutual inductance of the system needed to be studied. The next section gives an analytical model to better understand the phenomenon.

  9. Simulation of stress in an innovative combination of composite with metal sheet

    NASA Astrophysics Data System (ADS)

    Wróbel, A.; Płaczek, M.; Buchacz, A.; Słomiany, A.

    2016-08-01

    In this article research of stress impact in multi-point connection glass epoxy composite with a metal sheet with a rivet nuts was presented. Composite materials are increasingly used because of the good mechanical properties and low price. The laminates are composites of a layer structure, characterized by very high strength in the direction of the fibers, their weakness is not good toughness in a direction perpendicular to the layers. Mainly checking of displacements and stresses generated on the sheet as a result of pneumatic actuators load for composite boards was carried out. Glass-epoxy composite consisting of four layers of glass mat with a weight of 1000 g/m2 and an epoxy resin and hardener HG700 LG700 volume ratio of 38/100 was created. Next composite was fixed with steel plate with a rivet nuts and bolts. A model of laminate samples and plate was simulate in Siemens NX 8.5 software. The simulation results will determine stresses and displacements in conjunction newly designed composite sheet. Strength analysis was performed with the use of the module NX Advanced Simulation. FEM is an advanced method for solving systems of differential equations, based on the division of the field into finite elements for which the solution is approximated by specific functions, and performing the actual calculations only for nodes of this division. Due to the complexity of the created object to simplify the elements made to reduce the calculation time. This article presents the study of stresses and displacements in the composite plates joined with sheet metal, in summary of this article, the authors compare the obtainted results with the computer simulation results in the article: " The study of fix composite panel and steel plates on testing stand".

  10. Fatigue damage assessment of high-usage in-service aircraft fuselage structure

    NASA Astrophysics Data System (ADS)

    Mosinyi, Bao Rasebolai

    As the commercial and military aircraft fleets continue to age, there is a growing concern that multiple-site damage (MSD) can compromise structural integrity. Multiple site damage is the simultaneous occurrence of many small cracks at independent structural locations, and is the natural result of fatigue, corrosion, fretting and other possible damage mechanisms. These MSD cracks may linkup and form a fatigue lead crack of critical length. The presence of MSD also reduces the structure's ability to withstand longer cracks. The objective of the current study is to assess, both experimentally and analytically, MSD formation and growth in the lap joint of curved panels removed from a retired aircraft. A Boeing 727-232 airplane owned and operated by Delta Air Lines, and retired at its design service goal, was selected for the study. Two panels removed from the left-hand side of the fuselage crown, near stringer 4L, were subjected to extended fatigue testing using the Full-Scale Aircraft Structural Test Evaluation and Research (FASTER) facility located at the Federal Aviation Administration (FAA) William J. Hughes Technical Center. The state of MSD was continuously assessed using several nondestructive inspection (NDI) methods. Damage to the load attachment points of the first panel resulted in termination of the fatigue test at 43,500 fatigue cycles, before cracks had developed in the lap joint. The fatigue test for the second panel was initially conducted under simulated in-service loading conditions for 120,000 cycles, and no cracks were detected in the skin of the panel test section. Artificial damage was then introduced into the panel at selected rivets in the critical (lower) rivet row, and the fatigue loads were increased. Visually detectable crack growth from the artificial notches was first seen after 133,000 cycles. The resulting lead crack grew along the lower rivet row, eventually forming an 11.8" long unstable crack after 141,771 cycles, at which point the

  11. Ultrasonic Nondestructive Characterization of Adhesive Bonds

    NASA Technical Reports Server (NTRS)

    Qu, Jianmin

    1999-01-01

    Adhesives and adhesive joints are widely used in various industrial applications to reduce weight and costs, and to increase reliability. For example, advances in aerospace technology have been made possible, in part, through the use of lightweight materials and weight-saving structural designs. Joints, in particular, have been and continue to be areas in which weight can be trimmed from an airframe through the use of novel attachment techniques. In order to save weight over traditional riveted designs, to avoid the introduction of stress concentrations associated with rivet holes, and to take full advantage of advanced composite materials, engineers and designers have been specifying an ever-increasing number of adhesively bonded joints for use on airframes. Nondestructive characterization for quality control and remaining life prediction has been a key enabling technology for the effective use of adhesive joints. Conventional linear ultrasonic techniques generally can only detect flaws (delamination, cracks, voids, etc) in the joint assembly. However, more important to structural reliability is the bond strength. Although strength, in principle, cannot be measured nondestructively, a slight change in material nonlinearity may indicate the onset of failure. Furthermore, microstructural variations due to aging or under-curing may also cause changes in the third order elastic constants, which are related to the ultrasonic nonlinear parameter of the polymer adhesive. It is therefore reasonable to anticipate a correlation between changes in the ultrasonic nonlinear acoustic parameter and the remaining bond strength. It has been observed that higher harmonics of the fundamental frequency are generated when an ultrasonic wave passes through a nonlinear material. It seems that such nonlinearity can be effectively used to characterize bond strength. Several theories have been developed to model this nonlinear effect. Based on a microscopic description of the nonlinear

  12. Effect of thermal exposure, forming, and welding on high-temperature, dispersion-strengthened aluminum alloy: Al-8Fe-1V-2Si

    NASA Technical Reports Server (NTRS)

    Kennedy, J. R.; Gilman, P. S.; Zedalis, M. S.; Skinner, D. J.; Peltier, J. M.

    1991-01-01

    The feasibility of applying conventional hot forming and welding methods to high temperature aluminum alloy, Al-8Fe-1V-2Si (FVS812), for structural applications and the effect of thermal exposure on mechanical properties were determined. FVS812 (AA8009) sheet exhibited good hot forming and resistance welding characteristics. It was brake formed to 90 deg bends (0.5T bend radius) at temperatures greater than or equal to 390 C (730 F), indicating the feasibility of fabricating basic shapes, such as angles and zees. Hot forming of simple contoured-flanged parts was demonstrated. Resistance spot welds with good static and fatigue strength at room and elevated temperatures were readily produced. Extended vacuum degassing during billet fabrication reduced porosity in fusion and resistance welds. However, electron beam welding was not possible because of extreme degassing during welding, and gas-tungsten-arc welds were not acceptable because of severely degraded mechanical properties. The FVS812 alloy exhibited excellent high temperature strength stability after thermal exposures up to 315 C (600 F) for 1000 h. Extended billet degassing appeared to generally improve tensile ductility, fatigue strength, and notch toughness. But the effects of billet degassing and thermal exposure on properties need to be further clarified. The manufacture of zee-stiffened, riveted, and resistance-spot-welded compression panels was demonstrated.

  13. Development of a biaxial test facility for structural evaluation of aircraft fuselage panels

    SciTech Connect

    Roach, D.; Walkington, P.; Rice, T.

    1998-03-01

    The number of commercial airframes exceeding twenty years of service continues to grow. An unavoidable by-product of aircraft use is that crack and corrosion flaws develop throughout the aircraft`s skin and substructure elements. Economic barriers to the purchase of new aircraft have created an aging aircraft fleet and placed even greater demands on efficient and safe repair methods. Composite doublers, or repair patches, provide an innovative repair technique which can enhance the way aircraft are maintained. Instead of riveting multiple steel or aluminum plates to facilitate an aircraft repair, it is now possible to bond a single Boron-Epoxy composite doubler to the damaged structure. The composite doubler repair process produces both engineering and economic benefits. The FAA`s Airworthiness Assurance Center at Sandia National Labs completed a project to introduce composite doubler repair technology to the commercial aircraft industry. This paper focuses on a specialized structural test facility which was developed to evaluate the performance of composite doublers on actual aircraft structure. The facility can subject an aircraft fuselage section to a combined load environment of pressure (hoop stress) and axial, or longitudinal, stress. The tests simulate maximum cabin pressure loads and use a computerized feedback system to maintain the proper ratio between hoop and axial loads. Through the use of this full-scale test facility it was possible to: (1) assess general composite doubler response in representative flight load scenarios, and (2) verify the design and analysis approaches as applied to an L-1011 door corner repair.

  14. Desmosomes, corneosomes and desquamation. An ultrastructural study of adult pig epidermis.

    PubMed

    Chapman, S J; Walsh, A

    1990-01-01

    We recently developed a pig skin model to determine the role of corneosomes (modified desmosomes in the stratum corneum) and extracellular lipids in desquamation. The present study provides control morphometric data on the morphological changes in desmosomes and corneosomes leading to desquamation in adult pig epidermis in vivo. The extracellular space within desmosomes gradually widened from the basal to the granular layer, and decreased slightly in the stratum corneum. Mid-dense line broadening, and increased electron density of the distal light layers, coincided with membrane-coating granule extrusion in the outer granular layer. Corneocyte attachment correlated with corneosome distribution. Compactum packing was relatively tight and corneosomes were numerous. Cohesion was mainly peripheral in the disjunctum, and corneosomes were restricted to corneocyte edges. Adhesion had a tongue-and-groove appearance with corneosomes riveting corneocyte peripheries into a lipped groove on adjoining cells. Cells shed by peeling radially towards the lipped groove, and corneosomes decreased from lower to upper disjunctum. Corneosome breakdown commenced with an electron lucent band forming between the plug and lipid envelope. The plug was then unzipped from the lipid envelope and degraded. Corneosomes did not form squamosomes.

  15. Biomimetic soy protein nanocomposites with calcium carbonate crystalline arrays for use as wood adhesive.

    PubMed

    Liu, Dagang; Chen, Huihuang; Chang, Peter R; Wu, Qinglin; Li, Kaifu; Guan, Litao

    2010-08-01

    Despite the biodegradability, non-toxicity, and renewability, commercially available soy protein-based adhesives still have not been widely adopted by industry, partially due to their disappointing performances, i.e., low glue strength in the dry state and no glue strength in the wet state. In this study, biomimetic soy protein/CaCO(3) hybrid wood glue was devised and an attempt made to improve the adhesion strength. The structure and morphology of the adhesive and its fracture bonding interface and adhesion strength were investigated. Results showed that the compact rivets or interlocking links, and ion crosslinking of calcium, carbonate, hydroxyl ions in the adhesive greatly improving the water-resistance and bonding strength of soy protein adhesives. Glue strength of soy protein hybrid adhesive was higher than 6 MPa even after three water-immersion cycles. This green and sustainable proteinous hybrid adhesive, with high glue strength and good water-resistance, is a good substitute for formaldehyde wood glues.

  16. Neutron Radiographic Inspection of Industrial Components using Kamini Neutron Source Facility

    NASA Astrophysics Data System (ADS)

    Raghu, N.; Anandaraj, V.; Kasiviswanathan, K. V.; Kalyanasundaram, P.

    2008-03-01

    Kamini (Kalpakkam Mini) reactor is a U233 fuelled, demineralised light water moderated and cooled, beryllium oxide reflected, low power (30 kW) nuclear research reactor. This reactor functions as a neutron source with a flux of 1012 n/cm2 s-1 at core centre with facilitates for carrying out neutron radiography, neutron activation analysis and neutron shielding experiments. There are two beam tubes for neutron radiography. The length/diameter ratio of the collimators is about 160 and the aperture size is 220 mm×70 mm. Flux at the outer end of the beam tube is ˜106-107 n/cm2 s. The north end beam tube is for radiography of inactive object while the south side beam tube is for radiography of radioactive objects. The availability of high neutron flux coupled with good collimated beam provides high quality radiographs with short exposure time. The reactor being a unique national facility for neutron radiography has been utilized in the examination of irradiated components, aero engine turbine blades, riveted plates, automobile chain links and for various types of pyro devices used in the space programme. In this paper, an overview of the salient features of this reactor facility for neutron radiography and our experience in the inspection of a variety of industrial components will be given.

  17. Further studies on T*{sub {epsilon}} integral for curved crack growth

    SciTech Connect

    Lam, P.W.; Kobayashi, A.S.; Atluri, S.N.; Tan, P.W.

    1999-07-01

    T*{sub {epsilon}} integral values associated with stable, curved crack growth in biaxially loaded, fatigued precracked, 2024-T3 single edge notched (SEN) specimens were determined. The SEN specimens were loaded under combined Modes 1 and 2 and mimicked the flapping of a failed lap splice joint of a pressurized airplane fuselage. Most specimens were provided with a tear strap, which was either bonded, bonded and riveted, or integrally machined (machined pad-up) in the specimen. The stably growing crack curved and either penetrated or curved again upon hitting the tear strap. The displacement field, which was determined by Moire interferometry as well as with finite element analysis, was used to directly determine the T*{sub 2{epsilon}} and T*{sub 2{epsilon}} integral values. These T*{sub {epsilon}} values agreed reasonably well with those determined by an elastic-plastic finite element modeling of the experiments. T*{sub 1{epsilon}} was identical to that obtained previously for pure Mode I crack extension while the T*{sub 2{epsilon}} integral oscillated about its null value. The results of this study suggest that T*{sub 1{epsilon}} could represent the resistance for locally self-similar crack growth and that a crack will curve in the direction of vanishing T*{sub 2{epsilon}}.

  18. Identification of a two-component Class IIb bacteriocin in Streptococcus pyogenes by recombinase-based in vivo expression technology

    PubMed Central

    Armstrong, Brent D.; Herfst, Christine A.; Tonial, Nicholas C.; Wakabayashi, Adrienne T.; Zeppa, Joseph J.; McCormick, John K.

    2016-01-01

    Streptococcus pyogenes is a globally prominent bacterial pathogen that exhibits strict tropism for the human host, yet bacterial factors responsible for the ability of S. pyogenes to compete within this limited biological niche are not well understood. Using an engineered recombinase-based in vivo expression technology (RIVET) system, we identified an in vivo-induced promoter region upstream of a predicted Class IIb bacteriocin system in the M18 serotype S. pyogenes strain MGAS8232. This promoter element was not active under in vitro laboratory conditions, but was highly induced within the mouse nasopharynx. Recombinant expression of the predicted mature S. pyogenes bacteriocin peptides (designated SpbM and SpbN) revealed that both peptides were required for antimicrobial activity. Using a gain of function experiment in Lactococcus lactis, we further demonstrated S. pyogenes immunity function is encoded downstream of spbN. These data highlight the importance of bacterial gene regulation within appropriate environments to help understand mechanisms of niche adaptation by bacterial pathogens. PMID:27808235

  19. Theoretical Insight into the Conversion Mechanism of Glucose to Fructose Catalyzed by CrCl2 in Imidazolium Chlorine Ionic Liquids.

    PubMed

    Jing, Yaru; Gao, Jun; Liu, Chengbu; Zhang, Dongju

    2017-02-22

    To better understand the efficient transformation of glucose to fructose catalyzed by chromium chlorides in imidazolium-based ionic liquids (ILs), density functional theory calculations have been carried out on a model system which describes the catalytic reaction by CrCl2 in 1,3-dimethylimidazolium chlorine (MMImCl) ionic liquid (IL). The reaction is shown to involve three fundamental processes: ring opening, 1,2-H migration, and ring closure. The reaction is calculated to exergonic by 3.8 kcal/mol with an overall barrier of 37.1 kcal/mol. Throughout all elementary steps, both CrCl2 and MMImCl are found to play substantial roles. The Cr center, as a Lewis acid, coordinates to two hydroxyl group oxygen atoms of glucose to bidentally rivet the substrate, and the imidazolium cation plays a dual role of proton shuttle and H-bond donor due to its intrinsic acidic property, while the Cl(-) anion is identified as a Bronsted/Lewis base and also a H-bond acceptor. Our present calculations emphasize that in the rate-determining step the 1,2-H migration concertedly occurs with the deprotonation of O2-H hydroxyl group, which is in nature different from the stepwise mechanism proposed in the early literature. The present results provide a molecule-level understanding for the isomerization mechanism of glucose to fructose catalyzed by chromium chlorides in imidazolium chlorine ILs.

  20. Two-stage cyclic enzymatic amplification method for ultrasensitive electrochemical assay of microRNA-21 in the blood serum of gastric cancer patients.

    PubMed

    Li, Bingchen; Liu, Fei; Peng, Yuanyuan; Zhou, Yunlei; Fan, Wenxuan; Yin, Huanshun; Ai, Shiyun; Zhang, Xiansheng

    2016-05-15

    MicroRNA (miRNA) is riveting nowadays due to its close relevance to human malignancies. Exploiting a fast and convenient biosensor for sensitive and specific detecting miRNA is necessary and it has significant meaning for oncology. In this work, to understand the relationship between miRNA-21 and gastric cancer, we employ T4 RNA ligase 2 to initiate specific ligation reaction depending on the sequence of target RNA, and T7 exonuclease to catalyze the first stage cyclic enzymatic amplification method (CEAM) specifically, which also resting on the target RNA sequence, and the second stage CEAM to further amplify the response resulting from the initial target RNA. Our two-stage CEAM strategy can detect miRNA-21 as low as 0.36fM with remarkable specificity, and most importantly, it can be used to inspect the expression level of miRNA-21 in blood serum of gastric cancer patients. This will offer new perspective for figuring out the pathways of miRNA-21 involving in cancer.