Yingyu Wang

Evaluation and comparison of several multiaxial fatigue criteria

In this paper several multiaxial fatigue criteria are reviewed. The criteria are divided into three groups, according to the parameters used to describe the fatigue life or fatigue strength of materials. They are stress criteria, strain criteria and energy criteria. Their predictive capabilities are checked against the experimental data of six materials under proportional and nonproportional loading. Among the stress criteria, the criterion of Lee is in the best agreement with the test data. Among the strain criteria, the Kandil, Brown and Miller’s criterion has the best correlation with the experimental data of the materials employed. The Farahani’s criterion yields the most satisfactory result among the energy criteria. Its fatigue life correlation for 1045HR steel and 304 stainless steel fell within factors of 2 and 3, respectively.  2003 Elsevier Ltd. All rights reserved.

Role of Nonmetallic Inclusions in Fatigue, Pitting, and Corrosion Fatigue

Abstract A study was conducted of the effect of nonmetallic inclusions on the fatigue and corrosion fatigue resistance of a high-strength steel in 0.6 M sodium chloride (NaCl) solutions. Results indicated that angular calcium-aluminate inclusions played an important role in introducing cracks during air fatigue cycling; however, sulfide inclusions appeared to be the main contributors to sites for corrosion pits and subsequent crack initiation. Conventional consideration based on the stress intensification caused by such defects was insufficient to describe the role of nonmetallic inclusions in fatigue crack development in air and by corrosion pits during corrosion fatigue. However, it was considered that the interaction between geometric discontinuities (i.e., nonmetallic inclusions and cyclic loading) resulted in plasticity localization and, thus, facilitated crack development. Similarly, enhancement of localized dissolution resulting from plasticity localization contributed to corrosion pit development ...

Critical plane approach to multiaxial variable amplitude fatigue loading

A new critical plane approach based on the modified Manson-Coffin curve method (MMCCM) is presented in this paper for predicting fatigue lifetime under variable amplitude (VA) multiaxial fatigue loading. The critical plane is assumed to coincide with that material plane experiencing the maximum variance of the resolved shear strain. Fatigue damage is hypothesized to be a function of both the amplitude of the resolved shear strain and the so-called critical plane stress ratio. The latter quantity depends on the mean value and the variance of the stress perpendicular to the critical plane as well as on the variance of the shear stress resolved along the direction experiencing the maximum variance of the resolved shear strain. Load cycles are counted from the resolved shear strain time history by using the classic rain flow counting method. Palmgren-Miner’s linear damage rule is applied to estimate cumulative fatigue damage. The accuracy and reliability of the proposed approach is checked by using several experimental data taken from the literature. The estimated fatigue lives based on the new approach are seen to be in sound agreement with the experimental results.

Estimation of fatigue lifetime for selected metallic materials under multiaxial variable amplitude loading

This paper initially investigates the accuracy of two methods, i.e., the Maximum Variance Method (MVM) and the Maximum Damage Method (MDM), in predicting the orientation of the crack initiation plane in three different metallic materials subjected to multiaxial variable amplitude loading. According to the validation exercise being performed, the use of both the MVM and the MDM resulted in a satisfactory level of accuracy for selected three metals. Subsequently, three procedures to estimate the fatigue lifetime of metals undergoing multiaxial variable amplitude loading were assessed quantitatively. Procedure A was based on the MDM applied along with Fatemi-Socie’s (FS) criterion, Bannantine-Socie’s (BS) cycle counting method and Miner’s linear rule. Procedure B was based on the MVM, FS criterion, BS cycle counting method and Miner’s linear rule. Procedure C involved the MVM, the Modified Manson Coffin Curve Method (MMCCM), the classical rainflow cycle counting method and Miner’s linear rule. The results show that the usage of these three design procedures resulted in satisfactory predictions for the materials being considered, with estimates falling within an error band of three.