考虑硬度变化的结合面法向刚度建模

Consider a Combination of Surface Hardness Change Normal Stiffness Modeling

基于分形理论及M-B模型,引入微接触点域扩展因子,综合考虑微凸体弹性接触变形、弹塑性接触变形和完全塑性变形,进而考虑微凸体弹塑性变形阶段硬度随其几何形貌的改变而变化,建立对应的结合面法向接触刚度模型。通过软件仿真发现:考虑微凸体硬度随其几何形貌改变后,无量纲接触载荷较将硬度视为定值时要小,且随着分形维数的增大,二者差异在逐渐增大;考虑微凸体硬度随微凸体几何形状改变而变化后,结合面无量纲法向接触刚度相较将硬度视为定值时大;无量纲法向接触刚度随着无量纲接触载荷、分形维数和塑性指数的增大而增大,但随着无量纲特征分形粗糙度的增大而减小。

Based on fractal theory and M-B model, the introduction of micro-contact-point domain extension factor, considering the elastic contact asperity deformation contact elastoplastic deformation and fully plastic deformation, and then consider plastic deformation stage asperity hardness changes with its geometrical morphologies the change, combined with the establishment of the corresponding surface normal contact stiffness model. Through software emulation found： Consider asperity hardness subsequently change its geometric shape, dimensionless con- tact load is smaller than the hardness when deemed given value, and with the increase of the fractal dimension, the difference in gradually increasing ; after considering the asperity geometry change in hardness with asperity chan- ges, combined with surface dimensionless normal contact stiffness when compared to the hardness deemed given value; dimensionless normal contact stiffness as dimensionless contact load, fractal dimensionality and plasticity in- dex increases, but with the dimensionless fractal roughness increases.