Aerospace Science and Technology
Gholamreza Rashed
Abstract
In this paper, using the Abaqus finite element software, the torsional hysteresis of X52, X60, X65 steels under loadings with different torsion values, has been numerically investigated and they are compared to each other. The shear stress, effective stress, residual stress and elastic and plastic ...
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In this paper, using the Abaqus finite element software, the torsional hysteresis of X52, X60, X65 steels under loadings with different torsion values, has been numerically investigated and they are compared to each other. The shear stress, effective stress, residual stress and elastic and plastic shear strain distribution are presented in the numerical results. In this analysis, the “chaboche” kinematic hardening theory has been used to predict the behavior of the material in the plastic region. By comparing the difference percentage graphs of the steels under the same load, it has been concluded that the hysteresis loops in X65 steel will become stable sooner than X60 and in X60 steel they become stable sooner than X52.
Rahmatollah Ghajar; G. R. Rashed
Volume 4, Issue 3 , September 2007, , Pages 25-35
Abstract
Engineers have a range of methods to estimate the fatigue life under multiaxial conditions. Each of these predictive methods is generally subjected to restrictions, related to the inherent simplified assumptions. The objective of this paper is to evaluate the validity of commonly used multiaxial fatigue ...
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Engineers have a range of methods to estimate the fatigue life under multiaxial conditions. Each of these predictive methods is generally subjected to restrictions, related to the inherent simplified assumptions. The objective of this paper is to evaluate the validity of commonly used multiaxial fatigue criteria for different multiaxial loading conditions. The best criterion is identified through comparative analysis. The assessment is based on the experimental research findings of the SAE notched shaft, which is used as a benchmark [1]. The relative performance of three of existing multiaxial fatigue theories based on the strain criteria and the critical plane approaches are investigated. There is not any fixed strain life criterion that can predict the fatigue life best for different loading. Among all the critical plane models considered, Fatemi and Socie model [2] gives best fatigue life prediction for both multiaxial in phase and 90° out of phase loading cases.