A simplified non-linear kinematic hardening model for ratchetting and wear assessment in rolling contact

Abstract

A model for plasticity assessment in rolling contact is introduced, aimed at simulating the effect of the application of thousands of load cycles in a reasonable time. It is based on the non-linear kinematic and isotropic hardening model of Lemaitre and Chaboche in a simplified formulation suitable for contact problems and allows the calculation of accumulated plastic strain under the contact surface. Wear is introduced as an independent phenomenon, interacting with the plasticization process by removing material layers from the surface and modifying during the load process the stresses which each point is subjected to. The typical material responses to cyclic loading (elastic shakedown, plastic shakedown, and ratchetting) can be obtained by application of the present method; moreover, the effect of wear in stabilizing the strain field for a large number of cycles is shown. The model is validated through comparison with results obtained by other methods and by experiments

A method for predicting ratcheting and wear in rolling contact fatigue, taking technological residual stresses into consideration

“…The model is based on the assumption of component τ xz , which is the only stress component responsible for ratcheting and plastic flow, respectively, in contact. According to [14], this hypothesis is reasonable in the case of subsurface flow where, according to the Melan theorem, the kinematic hardening process is mainly affected by shear stress τ xz , which varies within a larger range than other deviatoric stress components, irrespective of the friction coefficient.…”

“…The Mazzu approach [14] is based on the non-linear kinematic hardening rule introduced by Lemaitre and Chaboche [27]. This approach is subsequently used for ratcheting prediction for rolling and rolling/sliding twodimensional contact.…”

“…A total of four computations are made per cycle, where the error value is computed in the following way: (13) where Our main goal is to determine the thickness of the worn layer after 500 000 cycles with the use of Mazzu's approach. For the purpose of accurately identifying the material parameters, we need to calculate the wear data in the interval between 100 000 and 500 000 cycles, based on the linear relationship between wear and the number of cycles [14]. The initial and optimized material parameters are listed in Tab.…”

“…A later approach, published by Jiang and Sehitoglu [13], is based on the assumption of an elastic stress field in the material and the application of procedures for the subsequent relaxation of stresses and strains [13]. A different approach was proposed by Mazzu [14], who presented a simplified nonlinear kinematic hardening model based on the ChabocheLemaitre plasticity model. According to Mazzu, the only component responsible for plastic flow is τ xz .…”

Influence of Induction Hardening on Wear Resistance in Case of Rolling Contact

“…One cycle contained three computations of worn layer under prescribed reference number of cycles. Afterwards, an error value was calculated in the following way (1) where h Wref k was the reference value of the worn layer and h W k was the value of worn layer reached after specified number of cycles. Reference values of worn layers with corresponding number of cycles were obtained from realized experiments.…”