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Investigation of Statistical Nature of Fatigue Properties

Description: Note presenting an experimental program to study the subject of metal fatigue and to determine and evaluate the fundamental factors which influence the behavior. The statistics of the fatigue-fracture curves and endurance limits were determined for a variety of metals and the effects of some metallurgical factors on the statistical nature of fatigue properties were shown.
Date: June 1952
Creator: Epremian, E. & Mehl, R. F.
Partner: UNT Libraries Government Documents Department

Investigation of the Statistical Nature of the Fatigue of Metals

Description: Note presenting an investigation which utilized the statistical methods developed in previous research to study the scatter found in aluminum alloys and the effect of the morphology of the carbide phase on the scatter in a eutectoid steel. The scatter in fatigue life for 24S and 75S aluminum was found to be comparable with that reported previously for steel.
Date: September 1953
Creator: Dieter, G. E. & Mehl, R. F.
Partner: UNT Libraries Government Documents Department

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

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

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

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

Effects of Prior Fatigue-Stressing of the Impact Resistance of Chromium-Molybdenum Aircraft Steel

Description: Note presenting a study of the impact behavior of normalized SAE X4130 steel after a variety of repeated stress treatments. Fatigue specimens of several types were used and the effects of surface finish, rest periods, stress amplitude, mean stress, stress concentration, and temperature during repeated stress received consideration.
Date: March 1943
Creator: Kies, J. A. & Holshouser, W. L.
Partner: UNT Libraries Government Documents Department

Dislocation Theory of the Fatigue of Metals

Description: "A dislocation theory of fatigue failure for annealed solid solutions is presented. On the basis of this theory, an equation giving the dependence of the number of cycles for failure on the stress, the temperature, the material parameters, and the frequency is derived for uniformly stressed specimens. The equation is in quantitative agreement with the data" (p. 183).
Date: September 12, 1947
Creator: Machlin, E. S.
Partner: UNT Libraries Government Documents Department

Fatigue Characteristics of Spot-Welded 24S-T Aluminum Alloy

Description: Report presenting the results of an investigation of the fatigue characteristics of spot-welded 24S-T aluminum alloy. The static shear strength of spot welds in lap joints of 24S-T alclad increases with increasing sheet thickness for thicknesses in the range of 0.025 inch to 0.032 inch.
Date: June 1943
Creator: Russell, H. W.; Jackson, L. R.; Grover, H. J. & Beaver, W. W.
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

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

Effect of fiber orientation on ball failures under rolling-contact conditions

Description: The rolling-contact fatigue spin rig was used to test balls of a bearing steel at maximum Hertz stresses of 600,000 to 750,000 psi. The effect of fiber orientation was observed with the ball track restricted to passing directly over the poles, coincident with the equator, or randomly around the ball. The polar areas were found to be weaker in fatigue than the nonpolar areas. This resulted in a much greater portion of the failures occurring in the polar areas than would be expected from a homogeneous material. The early failures are discussed.
Date: February 1957
Creator: Butler, Robert H.; Bear, H. Robert & Carter, Thomas L.
Partner: UNT Libraries Government Documents Department

Effect of fiber orientation in races and balls under rolling-contact fatigue conditions

Description: Report presenting a study of the effect of fiber orientation on fatigue life for both races and balls in the fatigue spin rig. In both balls and races, a concentration of fatigue failures was observed in that portion of the specimens with the highest angle of intersection of fiber flow lines from the surface.
Date: February 1958
Creator: Carter, Thomas L.
Partner: UNT Libraries Government Documents Department

Effect of lubricant base stock on rolling-contact fatigue life

Description: Report presenting five lubricants of different base stock tested using groups of 1/2-inch air-melt AISI M-1 tool-steel balls under rolling-contact fatigue conditions in the fatigue spin rig. A methyl silicone, mineral oil, glycol, sebacate, and adipate were used. All other test conditions were held constant at a test temperature of 100 degrees Fahrenheit and a maximum theoretical Hertz stress of 725,000 pounds per square inch in compression.
Date: February 1958
Creator: Carter, Thomas L.
Partner: UNT Libraries Government Documents Department

Effect of lubricant viscosity on rolling-contact fatigue life

Description: Report presenting a series of rolling-contact fatigue tests conducted in a bench rig at the Lewis laboratory. Four paraffin-base mineral oils of varying viscosity were used as lubricants. A continuous trend toward longer lift was observed with increasing lubricant viscosity over the range studied.
Date: October 1957
Creator: Carter, Thomas L.
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