粗糙表面弹性微动接触数值研究

A Numerical Analysis of Fretting Contact with Rough Surface

由于实际工程表面多为粗糙表面,这里研究了粗糙表面对微动接触中压力和切向应力的影响。研究接触过程中法向载荷保持不变,切向载荷为周期性的交变载荷。首先,建立接触算法和模型,其算法核心是利用共轭梯度法(CGM)计算微动接触中的表面压力及切向应力并使用快速傅里叶变换(FFT)加快计算速度。然后,在验证算法正确的基础上,分析正弦和非高斯粗糙表面接触的压力和切向应力的分布,通过对光滑与粗糙表面的研究对比,表明:(1)在正弦表面接触切向应力分布呈现尺寸效应;(2)在非高斯表面接触中,切向应力分布跟光滑表面形状类似;同时由于粗糙峰存在,粗糙表面下的切向应力比光滑表面下的要大,研究粗糙表面微动接触对实际工程具有重要意义。

Since the engineering surfaces are mostly rough,the effects of rough surfaces on pressure and tangential stress in fretting contact are studied.In the Present study,the normal load is fixed as constant,and the tangential load varies during the contact process.First,a fretting contact algorithms and model are built,where normal and tangential tractions are obtained via CGM and FFT algorithm is used to speed up the calculation of convolution.Second,on the basis of the correctness of the verification algorithm,the distribution of the pressure and shear stress on surface with a sinusoidal or non-Gaussian roughness are analyzed.By comparing the results of smooth surfaces with rough surfaces,it shows:(1)A similarity in stress distributions,independent of the contact size,is found for sinusoidal rough surface contacts;(2)In non-Gaussian surface contact,the shear stress distribution is similar to the smooth surface shape;Due to the existence of rough peaks,the shear stress under the rough surface is larger than the smooth surface.It is significant to study rough surface fretting contact in engineering practice.