Phenomenological Model of Accumulation of Fatigue Tribological Damage in the Surface Layer of Materials

Abstract

The paper shows that the task of analyzing the strength and durability of the material of the surface layer during friction is a difficult task. The study of the activation characteristics of surface destruction is complicated by the influence on the durability of many simultaneously proceeding synergistic processes. Based on the analysis of the computational models of fatigue wear under friction, in this work it has been proposed to take into account the presence of two damage accumulation areas and the type of destruction mechanism: the high-cycle fatigue area and the debris layer. Methods for estimating the parameters of the durability model for the region of high-cycle fatigue have been pro-posed. The relations of the stress-strain state and the characteristics of the fatigue strength of the material with the characteristics of the model of material destruction have been obtained. The analysis of the obtained relations showed that any physical impact on the surface, which leads to a decrease in structural heterogeneity and will prevent the development of cracks, contributes to an in-crease in wear resistance. Parameters have been analyzed to determine the durability of the debris layer and methods for their determination have been proposed. For the coefficient of environmental influence, the relations of the change in the activation energy of the surface layer with regard to the characteristics of the lubricant have been proposed. The obtained results are recommended for analyzing the reliability and durability of friction units of machines under fatigue wear conditions.