Investigation on dynamics performance of multibody system with rough surface

Abstract

This investigation aims to validate the effect of the rough contact surface on the dynamic responses of the multibody system based on the fractal theory. Firstly, a two-dimensional rough surface is described using the Weierstrass-Mandelbrot (W-M) function based on the fractal theory. The contact properties of a single asperity are estimated based on the Morag and Etsion (ME) model and Hertz law. The novel contact stiffness with roughness is derived from the size distribution function of the Majumdar and Bhushan (M-B) model. Secondly, a new hysteresis damping factor is derived to represent the energy dissipation during contact. Subsequently, a more general contact force model is proposed based on a nonlinear spring-damper vibration system, in which the novel contact stiffness is associated with the new hysteresis damping factor. The simulation results show that the newly introduced contact force model is a more generalized contact model and the existing contact force models are a special case under the condition of an ideal contact surface. Finally, the new contact force model is utilized to predict the dynamic responses of the one-dimension granular chain and the slider-crank mechanism with a clearance joint, which is validated by the experimental data.