A stress based damage mechanics model to simulate fretting wear of Hertzian line contact in partial slip

摘要

In this investigation, a new model for dry fretting wear of similar materials in Hertzian contact is proposed. The wear law which is dependent on material properties, applied load and sliding distance is proposed for similar materials under dry fretting wear conditions. Based on this law, a stress based damage mechanics equation for wear is formulated and a finite element model is developed to determine wear rates and wear coefficients. The modeling approach proposed is based on wear at the level of material microstructure and thus Voronoi tessellation is used to configure the microstructure of the bodies in contact. To simulate fretting wear, fatigue crack initiation and propagation along the grain boundaries, and grain removal technique is developed. Two distinct regions - wear initiation and wear propagation are observed from the results of the simulation. The results of the simulation are compared with the Archard wear law and the calculated wear coefficients are of the same order as suggested in the literature. Wear volume measurements for partial slip regime in fretting wear are obtained using the model and the effects of coefficient of friction, hardness and Young's modulus on fretting wear is studied. It is found that the wear rate is significantly influenced by hardness and Young's modulus while the applied coefficient of friction has little to no effect on the wear rate. A regression analysis of the results and a wear map technique to predict wear rates based on material parameters is also presented.