三维真实粗糙结合面法向接触刚度研究

Study on normal contact stiffness of three-dimensional real rough joint surfaces

针对目前建立结合面粗糙表面模型主要以统计数方法和分形方法居多的情况,利用LEXT OLS4000测量仪测量得到真实表面形貌数据,基于小波理论对数据进行了降噪、分解和重构等预处理,将数据导入到Pro/E中建立真实表面模型,运用ANSYS对结合面进行接触分析。带粗糙面的微元体被等效为无厚度界面和相同大小的光滑微元体串联,得出无厚度界面法向接触刚度。研究表明:表面形貌造成的接触应力分布不均匀和局部塑性变形导致结合面法向接触刚度随着压力的增加先增大后减小,并随着表面粗糙度参数值的增加而降低;不同的加工方式也影响着结合面的法向接触刚度。

For the problems in establishing rough surface mod- el at present, which is almost built through statistical mathematics or fractal method, topographical data of engineering real surface were captured by using morphology measuring instrument LEXT OLS4000. The real surface model was built in Pro/E using the data which were de-noised, decomposed, and reconstructed based on the wavelet theory. ANSYS is employed to research on the contact be- tween joint surfaces, and the method of calculating normal contact stiffness of rough surface without thickness is given according to the process that the micro-body with rough surface is equalized to the joints of a rough surface without thickness and a smooth micro- body. The study shows that normal contact stiffness increases firstly and then decreases with the increasing pressure and decreases with the increasing parameter of surface roughness because of uneven distribution of contact stress and localized plastic deformation due to surface topography, and affected by different processing technique.