接触载荷作用下非均质材料表层应力集中分析

Subsurface stress concentration of heterogeneous material under contact loading

利用数值化等效夹杂方法分析接触载荷作用下规则分布杂质单元影响材料表层最大von Mises应力大小和位置,并与相同工况下均质材料分析结果进行对比。在此基础上,研究不同分布参数下正态分布杂质单元对材料应力集中行为的影响。研究结果表明:在特定接触载荷作用下,均质材料表层最大von Mises应力随摩擦因数增大而增大,但杂质单元的存在将改变最大von Mises应力位置变化规律。非均质材料基体表层应力集中随分布杂质单元x方向平均坐标值增大而逐渐增大;随y方向平均坐标值增大而逐渐减小;随杂质单元半径增大而先增后减;分布杂质单元体积分数增大将导致基体最大von Mises应力上升。

A numerical equivalent inclusion method was used to analyze the maximum subsurface von Mises stress and its location for heterogeneous materials with regularly distributed heterogeneity elements under contact loading. The obtained results were compared with that of a homogeneous material under the same load. Further, parametric analyses were conducted to investigate the stress concentration caused by normally distributed heterogeneities in heterogeneous materials. The results show that the maximum subsurface von Mises stress of homogeneous material under a given load increases when friction coefficient becomes larger. Location of the maximum von Mises stress changes due to the existence of distributed heterogeneity elements. Subsurface stress concentration of the matrix becomes severer if the average x coordinate value of the normally distributed heterogeneities increases, or the average y coordinate value decreases. The maximum von Mises stress of materials rises firstly and then declines as the radius of inhomogeneity increases. The increase of volume fraction in heterogeneity results in a severer stress concentration in the matrix.