Three-Dimensional Repeated Elasto-Plastic Point Contacts, Rolling, and Sliding

Abstract

Accumulative plastic deformation due to repeated loading is crucial to the lives of many mechanical components, such as gears, stamping dies, and rails in rail-wheel contacts. This paper presents a three-dimensional numerical model for simulating the repeated rolling or sliding contact of a rigid sphere over an elasto-plastic half-space. This model is a semi-analytical model based on the discrete convolution and fast Fourier transform algorithm. The half-space behaves either elastic-perfectly plastically or kinematic plastically. The analyses using this model result in histories of stress, strain, residual displacement, and plastic strain volume integral (PV) in the half-space. The model is examined through comparisons of the current results with those from the finite element method for a simple indentation test. The results of rolling contact obtained from four different hardening laws are presented when the load exceeds the theoretical shakedown limit. Shakedown and ratchetting behaviors are discussed in terms of the PV variation. The effect of friction coefficient on material responses to repeated sliding contacts is also investigated.

Stochastic Multiscale Model of MEMS Stiction Accounting for High-Order Statistical Moments of Non-Gaussian Contacting Surfaces

“…These aspects will be investigated in a future work by substituting the asperity model considered in this work by a more evolved semi-analytical micro-mechanical model of surface interaction, e.g. based on a combination of conjugate gradient method, discrete convolution and Fast Fourier Transform allowing elasto-plasticity [54], [55] and/or adhesion [56] to be accounted for. However when considering cyclic loading, the constant Laplace pressure assumption in the meniscus might also have to be modified following the argumentation in [29], [47].…”

Modeling elasto-plastic indentation on layered materials using the equivalent inclusion method

“…If the reverse plasticity due to unloading and plastic accumulation due to repeated contacts are of interest, a more realistic strain hardening law needs to be used. The semi-analytical models (SAM) of elasto-plastic contact have been developed to analyze contacts of materials with different hardening behaviors, including the linear, power, isotropic, and kinetic laws (Jacq et al, 2002;Wang and Keer, 2005;Chen et al, 2008b). Sharing the same numerical framework for the plasticity loop with SAM, the present coating indentation model is capable of handling different hardening law of plasticity.…”

“…Here, the Newton-Raphson method is used to solve dk (Chen et al, 2008b). Increments of the plastic strain tensor de p ij can then be calculated by the general flow rule:…”

Rolling-Element Fatigue Testing and Data Analysis—A Tutorial

“…If a number of apparently identical bearings are tested to fatigue at a specific load, there is a wide dispersion of life among these bearings. For a group of 30 or more bearings, the ratio of the longest to the shortest life may be 20 In order to rank bearing materials, lubricants and design variables using rolling-element bench type fatigue testing and full-scale rolling-element bearing tests, the investigator needs to be aware of the variables that effect rolling-element fatigue life, and to be able to maintain and control them within an acceptable experimental tolerance. Once these variables are controlled, the number of tests and the test conditions need to be specified to assure reasonable statistical certainty of the final results.…”