基于共轭梯度法和快速傅立叶变换的粗糙表面微动接触数值研究

实际工程表面多为粗糙表面,研究粗糙表面的表面形貌对微动接触中压力和应力的影响具有重要意义。本文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,算法核心是利用共轭梯度法CGM(Conjugate gradient method)计算微动接触中的表面压力及切向应力并利用快速傅里叶变换FFT(Fast Fourier transform)加快计算速度。然后,对单峰表面、正弦表面和随机粗糙表面的接触进行数值研究。结果表明,表面幅值对切向载荷-位移曲线以及接触过程中的能量耗散有影响,表面幅值越大,相同切向载荷作用下产生的切向位移越大,能量耗散也越大。

A numerical analysis of fretting contact with rough surface based on conjugate gradient method and fast Fourier transform

Most engineering surfaces are rough,therefore surface morphology and roughness play an important role in fretting contact.In the present study,the normal load is fixed as constant,while the tangential load varies during the contact process.First,an efficient fretting contact model is developed to simulate various rough surfaces,where normal and tangential tractions are obtained via conjugate gradient method (CGM) and Fast Fourier transform (FFT) algorithm is used to speed up the calculation of convolution.Second,fretting contact on a surface with a single asperity,sinusoidal wave and random roughness are analyzed.Results show that surface amplitude has an impact on tangential load-displacement curve and energy dissipation.The tangential displacement and energy dissipation increase with the increase of the amplitude of roughness.