考虑微凸体相互作用及硬度变化的加卸载接触分形模型  

Fractal Model of Loading-Unloading Contact Considering Asperity Interaction and Hardness Changes

作　　者：王嘉豪 杨丽红[1] 

机构地区：[1]上海理工大学机械工程学院,上海

出　　处：《建模与仿真》2023年第1期290-303,共14页Modeling and Simulation

摘　　要：基于分形理论,建立了考虑微凸体的相互作用及硬度变化的加卸载接触模型。推导了单个微凸体在加卸载过程中接触面积、接触载荷、表面分离、变形量的关系式。根据接触面积的分布密度函数,推导粗糙表面的实际接触特性关系式,并通过数值计算分析了相关参数对接触特性的影响。结果表明:单个微凸体发生弹性变形时,卸载过程与加载过程完全一致;发生弹塑性变形时,随着微凸体加载结束时的变形量的增大,在相同接触载荷下,卸载时的接触面积越大,且不能完全回复;发生完全塑性变形时,微凸体在卸载过程中不回复。随着分形维度D的增大、尺度系数G的减小,粗糙表面越光滑,在相同接触载荷下,接触面积越大,表面分离减小。Based on fractal theory, a loading-unloading contact model considering the interaction of asperities and the change of hardness is established. The relationship between contact area, contact load, sur-face separation and deformation of a single asperity during loading and unloading is derived. Ac-cording to the distribution density function of the contact area, the actual contact characteristics of rough surfaces are derived, and the influence of relevant parameters on the contact characteristics is analyzed through numerical calculation. The results show that the unloading process is consistent with the loading process when a single asperity undergoes elastic deformation;when elastic-plastic deformation occurs, with the increase of deformation at the end of loading, the contact area at un-loading is larger under the same contact load, and cannot be fully recovered;when complete plastic deformation occurs, the asperities do not recover during unloading. With the increase of fractal di-mension D and fractal roughness G, the smoother the rough surface is, the larger the contact area is, and the smaller the surface separation is under the same contact load.

关 键 词：尺度系数 分形模型 分布密度函数 硬度变化 微凸体 接触载荷 分形维度 粗糙表面 

分 类 号：TP3[自动化与计算机技术—计算机科学与技术]