Showing papers in "International Journal of Fatigue in 1986"

TL;DR: In this article, the results of tests on specimens of FE 690 and AIMg4.5Mn using original and edited spectra are compared, and the results show that the crack initiation lives (compared with the fatigue life under the unedited sequence) were longer by 10-30% for EC9 and 20-55% for TWIST and MiniTWIST.

TL;DR: In this paper, the cyclic stress response of two lithium-containing aluminium alloys aged to contain ordered precipitates was studied in different environments over a range of plastic strains, where the specimens were cycled using tension-compression loading under total strain control.

TL;DR: In this paper, a new formula for the fatigue crack initation life is developed based on recent progress in the study of fatigue damage and crack initiation, and is substantiated experimentally.

TL;DR: In this paper, the capability and accuracy of several damage parameters to predict the mean stress effect on fatigue life of unnotched specimens are evaluated based on the results of strain-controlled fatigue tests with and without mean strain and mean stress.

TL;DR: In this article, the effects of lack of penetration and misalignment on the fatigue life of cruciform welded joints made of low alloy steel have been studied experimentally and theoretically.

TL;DR: In this article, the authors used the ultrasound technique (20 kHz loading freqeuncy) as a time and energy-saving method for measuring lifetimes under service loading conditions.

TL;DR: In this article, an analytical crack closure model is developed, based on the Dugdale model, but modified to take into account the plastically deformed material left in the wake of an advancing crack.

TL;DR: In this article, a new test method is proposed which aims to simulate the situation in real structures by cycling the specimen from yield strength downwards, and tests performed on transverse butt joints in structural steel under these conditions and under fixed stress ratios of −1, 0 and +0.5 showed that the proposed method gave the lowest fatigue lives.

TL;DR: In this paper, the effect of compressive peak stress on the maximum stress at the endurance limit, crack propagation rate, threshold stress intensity and crack closure was studied in a laboratory environment using two steels (SAE1045 and SAE1010) and two aluminium alloys (2024-T351 and 7075-T651).

TL;DR: The fatigue behavior of titanium 829 in its oil quenched (basketweave) and air cooled (aligned) microstructural forms has been examined at 600°C and room temperature under fully reversed, total strain controlled conditions as discussed by the authors.

TL;DR: In this paper, a method of determining the amount of heat liberated from a push-pull loaded fatigue specimen is presented, where the heat energy was determined by modelling the internal heat sources generated by electrically heating the specimen.

TL;DR: In this article, total strain controlled fatigue tests were run on a free standing NiCoCrAlY coating alloy, PWA 276, at 0.1 Hz at 650 C and at 1050 C, where it is extremely ductile, showing tensile elongation in excess of 100 percent.

TL;DR: In this article, a noncontact method of measuring the temperature field of a fatigue-loaded specimen in real time is presented, and a series of tests are carried out on specimens made from 18-8 stainless steel.

TL;DR: In this paper, the authors measured fatigue crack propagation rates for two titanium-based aeroengine disc alloys using compact tension test-pieces and used the threshold values associated with the minor cycles to predict the onset of minor cycle activity.

TL;DR: In this paper, the elastic stress distributions in some edge-notched geometries have been estimated from Creager and Paris's and Neuber's expressions, close to the notch root, these approximate solutions agree well with the finite element results.

TL;DR: In this paper, a fatigue loading spectrum proposed by Wirsching has been modified to yield a new spectrum more similar in appearance to the long-term stress history of deep water structures.

TL;DR: In this paper, the results of previous studies on acoustic emission during fatigue loading are used to relate the characteristics of the acoustic signals to the fracture processes occuring at the crack tip, which correspond to the formation of individual microfractures, to the process of macroplastic deformation and to stepwise crack propagation of the structurally disordered material, respectively.

TL;DR: In this paper, near-tip inplane displacement fields are determined on the surface of single-edge notched specimens of high strength (7075-T6) aluminium alloy using Moire interferometry stress intensity factors are estimated from near tip displacement gradients and from crackmouth opening measurements under the assumption of an inverse square root stress singularity.

TL;DR: In this article, the ratio Nexp/Ncalc for a relevant loading spectrum was used to predict the fatigue life of a component loaded under a second spectrum with a similar loading frequency distribution.

TL;DR: In this paper, the theory of statistical size effect was used to determine the fatigue life of randomly loaded specimens of 7075 T7351 alloy, and it was shown that the crack initiation life of larger components may be predicted using the theory, provided that the fatigue crack initiates from the surface and that the surface conditions of the laboratory specimen and component are technologically the same.

TL;DR: A study of cumulative fatigue damage using Miner's (1945) and Kramer's (1974) equations for stress ratios of -1 and 0 for low high, low-high mixed, high low, and high low mixed stress sequences has revealed close agreement between the theoretical and experimental values of fatigue damage and fatigue life.

TL;DR: In this paper, the influence of test frequency, material orientation, load waveform and specimen type on fatigue crack propagation and fracture mechanisms was investigated in injection molded polyamide-12.

TL;DR: The stress concentration factor for a hole near a circular edge notch has been estimated by comparison with other geometries for which stress concentration factors are readily available or can be estimated with confidence.

TL;DR: In this paper, a subsized fatigue specimen was designed to overcome the difficulty of machining a full-sized specimen from cast superalloy components, and a finite element analysis confirmed that the stress was maximum at the gauge section for any given set of clamping and tensile loads, and that the stresses developed due to clamping forces were negligible compared with those due to tensile or compressive loads.

TL;DR: In this article, the static strengths, crack growth lives and residual strengths have been predicted for a variety of aluminium alloys used in aeronautical structures, and the influence of product form and heat treatment on these properties assessed.

TL;DR: In this article, three methods have been used to calculate stress concentration factors of sharp edge notches, and the results are compared with those obtained with a finite element method, and it is shown that the most reliable estimates are obtained from K t geometry correction factors of elliptical holes, or from K geometry correction factor of cracked specimens.

TL;DR: In this paper, a general theory of fracture is proposed which combines both atomistic and continuous approaches to describe the spatial stress distribution around the crack tip and enables the heat release area, moment of fracture and dynamics of crack formation to be determined.

TL;DR: In this article, the authors investigated the relationship between the log life and log crack depth for individual specimens and found no significant differences between the standard deviations of log life to crack initiation, for propagation or to final failure.

TL;DR: In this paper, two grades of 220MO7 steel were used to study the influence of a magnetic field on fatigue life, and both materials showed a similar shift in their S/N curves in the presence of a saturated magnetic field.