Mean stress significantly influence the fatigue life predictions of metallic materials. The Walker mean stress equation with its additional material parameter w provides good predictions for a wide range of materials. Unfortunately, additional tests are necessary to determine the Walker exponent w. In order to overcome this shortcoming, for aluminum alloys, the Walker exponent w was correlated linearly with the sum of ultimate tensile strength and true fracture strength. Then, a Walker exponent corrected effective strain energy density criterion was developed by incorporating the Walker mean stress equation into the strain life curve. The capability of fatigue life prediction for the developed model was checked against the tested data of 304 L stainless steel, SAE 1045 steel, 7075‐T651 aluminum alloy, and Incoloy 901 superalloy, and comparisons were also performed by using the Lv's Walker exponent corrected model. The developed model provides more satisfactory results, especially for the considered materials in loading with mean stress.

The objective of the present paper is to derive some useful approximations for estimating the strain-controlled fatigue properties and cyclic deformation of wrought aluminum alloys from hardness and monotonic tensile properties. A variety of relationships and correlations among monotonic tensile properties, Brinell hardness, cyclic deformation and strain-controlled fatigue properties are developed for wrought aluminum alloys. A simple method is proposed for prediction of the strainlife curve requiring only ultimate tensile strength and modulus of elasticity. Prediction capability of the proposed method is evaluated for 25 kinds of wrought aluminum alloys with ultimate tensile strength between 120 MPa and 650 MPa. The proposed method provides good approximations of the strain-life curve.

Most of the existing methods for estimating cyclic strength coefficient and cyclic strain hardening exponent are developed based on the experimental data of steel alloys or aluminum alloys. For titanium alloys, approximation methods are scarce in literature. In the present paper, the compatibility between Manson‐Coffin and Ramberg‐Osgood equations are evaluated using the 18 cyclic stress‐strain curves obtained from 13 titanium alloys. It is found that there is a reasonable correlation between the Ramberg‐Osgood's parameters (K′ and n′) and the Manson‐Coffin's parameters (σ′f, ϵ′f, b and c). However, the indirect methods utilizing the Manson‐Coffin's parameters predicted from monotonic tensile data cannot be successfully applied to estimate the Ramberg‐Osgood's parameters on the basis of the compatibility assumption.

The objective of this study is to derive a method for estimating the cyclic shear deformation properties (the cyclic shear strength coefficient and cyclic shear strain hardening exponent) of steels from common tensile properties. For this purpose, equations that relate the cyclic shear strength coefficient and cyclic shear strain hardening exponent to the monotonic tensile properties (the ultimate tensile strength and monotonic yield strength) are established on the basis of the 15 kinds of steel taken from the technical literature. Validity of some of the more commonly used methods of estimating cyclic shear deformation properties is examined and compared to the correlations proposed in this study. The proposed method is shown to be better used to estimate the cyclic shear deformation properties.