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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

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

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

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

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

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

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 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

Interim Report on a Fatigue Investigation of a Full-Scale Transport Aircraft Wing Structure

Description: Note presenting results of an investigation of the fatigue strength of several full-scale aircraft wing structures. The 34 fatigue failures which resulted from the tests were of four main types and occurred in three principal localities on the test wings. Results regarding the definition of fatigue failure, load history of specimens, description of fatigue failures, spread in fatigue life, stress concentration factors, rate of crack growth, and effect of fatigue damage on natural frequency and damping are provided.
Date: April 1953
Creator: McGuigan, M. James, Jr.
Partner: UNT Libraries Government Documents Department

Some Observations on the Relationship Between Fatigue and Internal Friction

Description: Results are presented of an investigation made to determine the internal friction and fatigue strength of commercially pure 1100 aluminum under repeated stressing in torsion at various temperatures and stress levels in an effort to find if there exists any correlation between internal friction and fatigue characteristics.
Date: September 1956
Creator: Valluri, S. R.
Partner: UNT Libraries Government Documents Department

Fatigue Resistance of Duralumin

Description: Where, in the following report, mention is made of fatigue, it always refers to the weakening of the material produced by rapidly changing stresses below the point of elasticity. The alternating stress was obtained by a test bar which was held at one end and subjected to rotation. Most of the tests were conducted on connecting rods.
Date: September 1922
Partner: UNT Libraries Government Documents Department

Comparison of Fatigue Strengths of Bare and Alclad 24S-T3 Aluminum-Alloy Sheet Specimens Tested at 12 and 1000 Cycles Per Minute

Description: Note presenting the results of axial fatigue tests conducted on 0.032-inch-thick flat-sheet specimens of bare and alclad 24S-T3 aluminum alloy to determine the effect of frequency of loading on the fatigue strengths of these materials. The number of cycles to failure varied from about 150 to over 10,000,000 and tests were conducted using completely reversed axial load at two frequencies of loading.
Date: December 1950
Creator: Smith, Frank C.; Brueggeman, William C. & Harwell, Richard H.
Partner: UNT Libraries Government Documents Department

Cumulative Fatigue Damage of Axially Loaded Alclad 75S-T6 and Alclad 24S-T3 Aluminum-Alloy Sheet

Description: Note presenting the results of cumulative-fatigue-damage tests made on 607 specimens machined from alclad 75S-T6 aluminum-alloy sheet 0.064 inch thick and 198 specimens of alclad 24S-T3 and alclad 75S-T6 aluminum-alloy sheet 0.032 inch thick. The cumulative-damage ratio was calculated as the sum of the ratios of the numbers of cycles applied at the different stress levels to the number of cycles at the same stress level that would cause failure.
Date: September 1955
Creator: Smith, Ira; Howard, Darnley M. & Smith, Frank C.
Partner: UNT Libraries Government Documents Department

Improvement of Fatigue Life of an Aluminum Alloy by Overstressing

Description: "Fatigue tests were made on some 1.375-inch-diameter and 0.300-inch diameter specimens of a 17S-T aluminum alloy rod. One test of a large specimen was run continuously to failure at a maximum stress of 22,000 pounds per square inch. In two other tests of large specimens, thin surface layers were removed periodically until failure occurred. The same nominal maximum stress of 22,000 pounds per square inch was used throughout the two tests and the load on the fatigue machine was lowered accordingly after the removal of each surface layer" (p. 1).
Date: August 1942
Creator: Stickley, G. W.
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 Alclad

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

Effect of Alternately High and Low Repeated Stresses Upon the Fatigue Strength of 25S-T Aluminum Alloy

Description: "Fatigue tests were made on one lot of 3/4 inch diameter rolled-and-drawn 25S-T aluminum-alloy rod normal in composition and tensile properties. The specimens were tested at 3500 cycles per second in a rotating-beam fatigue test machine. Tests were made for three ratios (20:1, 50:1, and 200:1) of the number of cycles applied at low stress to the number applied at high stress. In general, failure occurred when the number of cycles at either the low or the high stress approached the ordinary fatigue curve for the material, regardless of the sequence in which the stresses were applied" (p. 1).
Date: January 1941
Creator: Stickley, G. W.
Partner: UNT Libraries Government Documents Department