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Effects of Environment on the Low-Cycle Fatigue Behavior of Type 304 Stainless Steel

Description: The low-cycle fatigue behavior of Type 304 stainless steel has been investigated at 593 degrees C in a dynamic vacuum of better than 1.3 x 10⁻⁶ Pa (10⁻⁸ torr). The results concerning the effects of strain range, strain rate and tensile hold time on fatigue life are presented and compared with results of similar tests performed in air and sodium environments. Under continuous symmetrical cycling, fatigue life is significantly longer in vacuum than in air; in the low strain range regime, the effect of sodium on fatigue life appears to be similar to that of vacuum. Strain rate (or frequency) strongly influences fatigue life in both air and vacuum. In compressive hold-time tests, the effect of environment on life is similar to that in a continuous-cycling test. However, tensile hold times are nearly as damaging in vacuum as in air. Thus, at least for austenitic stainless steels, the influence of the environment of fatigue life appears to depend on the loading waveshape.
Date: December 1979
Creator: Argonne National Laboratory. Materials Science Division.
Partner: UNT Libraries Government Documents Department

Delayed Failure Hydrogen Embrittlement of Zirconium : Quarterly Report no. 1, September 15, 1961 to December 14, 1961

Description: Abstract: "The purpose of this investigation is to determine the extent to which zirconium exhibits delayed failure (static fatigue) as caused by a combination of absorbed hydrogen and applied stress. Both notched and unnotched specimens of unalloyed zirconium and Zircaloy-2 are being initially hydrogenated to 200 ppm by means of a modified Sieverts apparatus, and delayed failure studies are proceeding at room-temperature. Thus far only preliminary data on unnotched, unalloyed zirconium are available; at the 200 ppm hydrogen level, this material appears to be relatively insensitive to delayed failure at room-temperature."
Date: January 3, 1962
Creator: Weinstein, Daniel. & Holtz, F. C.
Partner: UNT Libraries Government Documents Department

Delayed Failure Hydrogen Embrittlement of Zirconium : Quarterly Report No. 2, December 15, 1961 to March 14, 1962

Description: Abstract: "The purpose of this investigation is to determine the extent to which zirconium and zirconium alloys exhibit delayed failure (static fatigue) as caused by a combination of absorbed hydrogen and applied stress. Both notched and unnotched specimens of unalloyed zirconium and Zircaloy-2 have been hydrogenated to 200 ppm by means of a modified Sieverts apparatus; specimens were evaluated at room temperature. Thus far, no time-dependent fracture has been observed which can be attributed to the delayed failure phenomenon; it appears that these materials are relatively insensitive to static fatigue. The effects of grain size, temperature, cold deformation, and superheated water and steam corrosion on susceptibility to delayed failure are being determined."
Date: March 30, 1962
Creator: Weinstein, Daniel. & Holtz, F. C.
Partner: UNT Libraries Government Documents Department

Delayed Failure Hydrogen Embrittlement of Zirconium : Quarterly Report No. 3, March 15, 1962 to June 14, 1962

Description: The following report is the third Quarterly Report in a series whose investigative purpose is to determine the extent to which zirconium and zirconium alloys exhibit delayed failure as caused by a combination of absorbed hydrogen and applied stress.
Date: June 6, 1962
Creator: Weinstein, Daniel. & Holtz, F. C.
Partner: UNT Libraries Government Documents Department

Delayed Failure Hydrogen Embrittlement of Zirconium : Summary Report, September 15, 1961 to September 14, 1962

Description: The following report summarizes an investigation made to determine the extent to which zirconium and zirconium alloys exhibit delayed failure as caused by a combination of absorbed hydrogen and applied stress during the period September 15, 1961, to September 14, 1962.
Date: October 10, 1962
Creator: Weinstein, Daniel. & Holtz, F. C.
Partner: UNT Libraries Government Documents Department

Studies of structural failure due to acoustic loading

Description: A discussion of the acoustic fatigue problem of aircraft structures along with data pertaining to the acoustic inputs from some power plants in common use. Comparisons are given for results of fatigue tests of flat panels and cantilever beams exposed to random- and discrete-type inputs. Both the stress level of the test and type of model are significant, so no generalizations can be made at this time.
Date: July 1957
Creator: Hess, Robert W.; Fralich, Robert W. & Hubbard, Harvey H.
Partner: UNT Libraries Government Documents Department

Further investigation of fatigue-crack propagation in aluminum-alloy box beams

Description: Report presenting testing of twenty-one box beams constructed according to nine designs that were subjected to fatigue tests at one load level to study fatigue-crack propagation and accompanying stress redistribution. Six designs had stiffeners riveted to the skin, two had integrally stiffened covers, and one had stiffeners bonded to the skin. Results regarding crack initiation, crack propagation, and stresses are provided.
Date: June 1958
Creator: Hardrath, Herbert F. & Leybold, Herbert A.
Partner: UNT Libraries Government Documents Department

Fatigue-crack propagation in aluminum alloy box beams

Description: Report presenting fatigue testing of eighteen box beams constructed according to four designs in order to study fatigue-crack propagation and accompanying stress redistribution. Two designs had stiffeners riveted to the cover, one had stiffeners bonded to the cover, and one had an integrally stiffened cover machined from a plate. Results regarding crack initiation, crack propagation, and stress distribution are provided.
Date: August 1956
Creator: Hardrath, Herbert F.; Leybold, Herbert A.; Landers, Charles B. & Hauschild, Louis W.
Partner: UNT Libraries Government Documents Department

Fatigue-crack-propagation and residual-static-strength results on full-scale transport-airplane wings

Description: Report presenting results of fatigue-crack-propagation studies conducted during fatigue tests of nine complete wings from C-46 airplanes. Static tests of the wings with fatigue failures are also described. Results regarding fatigue-crack propagation and residual static strength testing are provided.
Date: December 1956
Creator: Whaley, Richard E.; McGuigan, M. J., Jr. & Bryan, D. F.
Partner: UNT Libraries Government Documents Department

Preliminary results from fatigue tests with reference to operational statistics

Description: Simple elements were subjected to repeated loads of variable ampliture, chosen in such a way that they may be regarded as approximations to the operational loads (gust and maneuver) experienced by an airplane. The effect of varying some parameters was investigated briefly. Some discussion is given of the question whether a design according to current (1938 German) requirements for static strength is adequate from the fatigue point of view, and existing requirements on fatigue strength are compared,.
Date: May 1950
Creator: Gassner, E.
Partner: UNT Libraries Government Documents Department

Experimental investigation of notch-size effects on rotating-beam fatigue behavior of 75S-T6 aluminum alloy

Description: Report presenting an investigation to study the influence of size, particularly notch-size effect, on extruded 75S-T6 aluminum-alloy test specimens under rotating bending. Results regarding fatigue strength and fatigue-notch factor are provided.
Date: November 1954
Creator: Hyler, W. S.; Lewis, R. A. & Grover, H. J.
Partner: UNT Libraries Government Documents Department

An experimental investigation of the behavior of 24S-T4 aluminum alloy subjected to repeated stresses of constant and varying amplitudes

Description: Report presenting a description of a device for adapting rotating-beam fatigue testing machines for tests in which the amplitude of stress is continuously varied. Testing was conducted on 24S-T aluminum-alloy specimens subjected to stresses with amplitudes varying according to sinusoidal and exponential functions.
Date: October 1952
Creator: Hardrath, Herbert F. & Utley, Elmer C., Jr.
Partner: UNT Libraries Government Documents Department

Results of axial-load fatigue tests on electropolished 2024-T3 and 7075-T6 aluminum-alloy-sheet specimens with central holes

Description: From Summary: "Results are presented of axial-load fatigue tests at stress ratios of 0 and -1.0 on electropolished 2024-T3 (24S-T3) and 7075-T6 (75S-T6) aluminum-alloy-sheet specimens with central holes. The specimen widths and hole diameters were varied in order to provide data suitable for a study of the effect of notch size. The data are compared with previously published results of tests on unnotched electropolished specimens and on unpolished specimens containing central holes."
Date: March 1956
Creator: Landers, Charles B. & Hardrath, Herbert F.
Partner: UNT Libraries Government Documents Department

Fatigue and Recuperation Curves under Varying Lengths of Intertrial Recovery Periods

Description: The purposes of this study were to investigate the effect that strength level had upon fatigue and recuperation under the two conditions of five- and thirty-second interval duration periods. Another purpose was to compare the results of this study to similar studies using male subjects in order to determine if women's response patterns to tests of strength were similar to those of men.
Date: August 1968
Creator: Osborne, Jacquelyn
Partner: UNT Libraries

Low-Frequency Fatigue-Crack Propagation in Type 304 Stainless Steel at 482 and 593°C

Description: This report presents results from an investigation on the low-frequency fatigue-crack growth behavior of Type 304 stainless steel at 482 and 593 C. Included were continuous-cycling tests with a triangular loading waveform, waveshape-effects tests employing slow-fast, fast-slow and square waveforms, creep-crack growth rate tests, and a block-loading test. The results are compared with similar test data from the literature, and the block-loading test results are compared with results predicted by integrating the relations for da/dN obtained under constant conditions.
Date: June 1980
Creator: Raske, D. T.
Partner: UNT Libraries Government Documents Department

Static strength of aluminum-alloy specimens containing fatigue cracks

Description: Report presenting fatigue testing of seven configurations of specimens made of 2024 and 7075 aluminum alloys in rolled and extruded form and subjected to repeated axial loads until fatigue cracks of various lengths were formed. Small cracks were found to result in disproportionately large reductions of static strength.
Date: October 1956
Creator: McEvily, Arthur J., Jr.; Illg, Walter & Hardrath, Herbert F.
Partner: UNT Libraries Government Documents Department

The application of high-temperature strain gauges to the measurements of vibratory stresses in gas-turbine buckets

Description: The feasibility of measuring the vibration in the buckets of a gas turbine under service conditions of speed and temperature was determined by use of a high temperature wire strain gauge cemented to a modified supercharger turbine bucket. A high-temperature wire strain gauge and the auxiliary mechanical and electrical equipment developed for the investigation are described.
Date: April 1947
Creator: Kemp, R. H.; Morgan, W. C. & Manson, S. S.
Partner: UNT Libraries Government Documents Department

Axial fatigue tests at zero mean stress of 24S-T and 75S-T aluminum-alloy strips with a central circular hole

Description: From Summary: "Axial fatigue tests at zero mean stress have been made on 0.032- and 0.064-inch 24S-T and 0.032-inch 75S-T sheet-metal specimens 1/4, 1/2, 1, and 2 inches wide without a hole and with central holes giving a range of hole diameter D to specimen width W from 0.01 to 0.95. No systematic difference was noted between the results for the 0.032-inch and the 0.064-inch specimens although the latter seemed the more consistent. In general the fatigue strength based on the minimum section dropped sharply as the ration D/W was increased from zero to about 0.25. The plain specimens showed quite a pronounced decrease in fatigue strength with increasing width. The holed specimens showed only slight and rather inconclusive evidence of this size effect. The fatigue stress-concentration factor was higher for 75S-T than for 24S-T alloy. Evidence was found that a very small hole would not cause any reduction in fatigue strength."
Date: August 1948
Creator: Brueggeman, W. C. & Mayer, M., Jr.
Partner: UNT Libraries Government Documents Department

Axial-load fatigue properties of 24S-T and 75S-T aluminum alloy as determined in several laboratories

Description: In the initial phase of a NACA program on fatigue research, axial-load tests on 24S-T3 and 75S-T6 aluminum-alloy sheet have been made at the Battelle Memorial Institute and at the Langley Aeronautical Laboratory of the National Advisory Committee for Aeronautics. The test specimens were polished and unnotched. The manufacturer of the material, the Aluminum Company of America, has made axial-load tests on 24S-T4 and 75S-T6 rod material. The test techniques used at the three laboratories are described in detail; the test results are presented and are compared with each other and with results obtained on unpolished sheet by the National Bureau of Standards. (author).
Date: 1954
Creator: Grover, H. J.; Hyler, W. S.; Kuhn, Paul; Landers, Charles B. & Howell, F. M.
Partner: UNT Libraries Government Documents Department

Early detection of cracks resulting from fatigue stressing

Description: Report discusses an apparatus that may be used for indicating the formation of fatigue cracks or for following the progress of cracks. Details of the experiment and discussion of the way in which the deflection-crack area relationship may be used to monitor fatigue cracks are included.
Date: September 1944
Creator: Bennett, John A.
Partner: UNT Libraries Government Documents Department

An analysis of the fatigue life of an airplane wing structure under overload conditions

Description: From Introduction: "Fatigue life expectancy in normal transport operations was investigated in reference 1 and was found to be of equal importance with single-gust life. The effect of overload operation of transport airplanes on the probability of encountering single critical gusts was investigated in reference 2 and the frequency of critical gusts was found to increase rapidly with overload. The effect of overload operation on fatigue strength, however, has not heretofore been evaluated, hence the investigations of references 1 and 2 are combined herein to permit such evaluation and to determine the relative importance of fatigue and single-gust failures under conditions of overload operation."
Date: February 1946
Creator: Reisert, Thomas D
Partner: UNT Libraries Government Documents Department

Fatigue strength and related characteristics of aircraft joints 1: comparison of spot-weld and rivet patterns in 24S-T Alclad and 75S-T Aclad

Description: 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).
Date: December 1944
Creator: Russell, H. W.; Jackson, L. R.; Grover, H. J. & Beaver, W. W.
Partner: UNT Libraries Government Documents Department

Fatigue strengths of aircraft materials : axial-load fatigue tests on notched sheet specimens of 24S-T3 and 75S-T6 aluminum alloys and of SAE 4130 steel with stress-concentration factor of 1.5

Description: Report presenting results of axial-load fatigue tests on notched specimens of three sheet materials: 24S-T3 and 75S-T6 aluminum alloys and normalized SAE 4130 steel. Tests were run at four levels of nominal mean stress.
Date: February 1952
Creator: Grover, H. J.; Hyler, W. S. & Jackson, L. R.
Partner: UNT Libraries Government Documents Department

Fatigue strengths of aircraft materials: axial load fatigue tests on unnotched sheet specimens of 24S-T3 and 75S-T6 aluminum alloys and of SAE 4130 steel

Description: Report presenting information on the axial-load fatigue behavior of unnotched specimens of 24S-T3 and 75S-T6 aluminum alloys and normalized SAE 4130 steel. The primary objectives of the investigation were to determine fatigue strengths and measurements of damage due to stress level are provided. Results regarding static strength tests, fatigue strength tests, fatigue damage tests, and results at high and low speeds are provided.
Date: March 1951
Creator: Grover, H. J.; Bishop, S. M. & Jackson, L. R.
Partner: UNT Libraries Government Documents Department