考虑临界变形量变化的结合面法向接触刚度计算模型

摘要

Considering the critical deformation change of asperities contact,a calculation model for normal contact stiffness of joint surfaces is presented.The topographic characteristics of joint surfaces are described based on fractal geometry,and the fractal parameters D and G of fractal function are derived from measurement data of surface topography.According to the elastic-plastic deformation contact theory,the contact deformation characteristics of asperities are analyzed,and the critical deformation estimation model is presented,which expresses critical deformation as the function of fractal parameters and contact deformation of asperities,and the contact stiffness calculation model of single asperity is brought forward considering critical deformation change.The asperity statistical distribution function of rough surface is built based on the fractal theory.Additionally,combining the contact stiffness calculation model of single asperity and the asperity statistical distribution function, the calculation model for normal contact stiffness of joint surfaces is built.Finally,the comparison between calculated results and experimental data verifies the rationality of the proposed model.%考虑微凸体接触过程中临界变形量变化，建立结合面法向接触刚度计算模型。采用分形几何表征结合面的形貌特征，由表面形貌测量数据得到分形函数的分形参数 D 和 G 。采用弹塑性变形接触理论分析微凸体的接触变形特征，得到微凸体的临界变形量估计模型，其是分形参数和微凸体接触变形量的函数，进而得到考虑临界变形量变化的单个微凸体的接触刚度计算模型。由分形理论得到粗糙表面微凸体分布函数，微凸体分布函数与单个微凸体接触刚度计算模型结合得到结合面的法向接触刚度计算模型。通过对比计算结果与实验数据，验证了所提模型的合理性。