Contact analysis of measured surfaces based on modified interacting and coalescing Hertzian asperities (ICHA) model with oblique contact asperities

The contact mechanism for joint surfaces is important for predicting the loading process and dynamic properties of precision machinery products. A multiasperity model considering the lateral interaction and coalescence of contact regions with oblique asperity contact, the interacting and coalescing Hertzian asperities (ICHA) model, is introduced in this work. Contact angle alpha and radius of curvature R(r) are vital parameters that are directly calculated based on grid points measured from the milling and grinding surfaces. Numerical simulations of alpha and R(r) were analysed. The results show that the proposed model is more effective at improving the contact area versus force relationship than various asperity models for low and middle contact forces. alpha and R(r) follow a Gaussian distribution. Because of the existence of coalescence, they decrease with increasing contact force. Furthermore, the alpha and R(r) in the startup phase are crucial data that can be used to judge the effects of oblique asperity contact. They are greatly influenced by fractal dimension D and fractal roughness G. From the comparisons with the surfaces generated by Weierstrass-Mandelbrot function, it is suggested that to obtain an accurate contact prediction in the loading process, oblique contact is as important as lateral interaction and coalescence.