薄膜粗糙表面有摩擦接触问题的数值计算研究

Numerical Calculation of Contact Problem for Rough Surfaces of Thin Film with Friction

采用ANSYS的APDL语言编程通过参数化变量方式实现了薄膜粗糙表面有摩擦接触问题的整个建模与分析过程,其中包括参数化生成满足高斯分布的随机粗糙表面与计及摩擦因数和薄膜/基体弹性模量比变化情况下的自动有限元分析过程。计算结果表明:当摩擦因数一定时,随着薄膜/基体弹性模量比的增大,应力分布逐渐向基体深处扩展,粗糙表面上各点接触压力一致减小,接触压力峰值减小的最大幅度为9.0%;当弹性模量比一定时,摩擦因数的变化对基体部分应力分布的影响不大,然而随着摩擦因数的增加,粗糙表面上各点接触压力增大,接触压力峰值增加的最大幅度为13.2%,可见摩擦因数和弹性模量比对薄膜粗糙表面的接触应力有明显影响。

ANSYS Parametric Design Language was adopted to realize modeling and analyzing of contact problem for rough surfaces of thin film with friction in terms of parametric variables, which includes parametric modeling of random rough surface based on Gaussian distribution and automating finite element analysis at various friction coefficient and elastic modulus ratio of thin film and substrate. The results of finite element analysis were discussed. The calculational results show that the stress distribution is gradually expanding towards the base of substrate, the contact pressure decreases, the maximal contact pressure decreases with the value of 9%, when increasing the value of elastic modulus ratio of thin film and substrate at constant friction coefficient. Various friction coefficient has little influence on the stress state of substrate, the contact pressure of rough surface increases with the increase of friction coefficient, the maximal contact pressure increases with the value of 13.2% ,when the value of elastic modulus ratio of thin film and substrate is constant. It is shown that various friction coefficient and various value of elastic modulus ratio of thin film and substrate have obvious influence on the contact pressure of rough surface.