Nonlinear dynamic analysis of multi-link mechanism considering the wear effect of kinematic pair

The wear of motion pair is a common phenomenon in mechanisms and can significantly affect the dynamic behavior of mechanical systems, posing a huge challenge to the precise dynamic modeling and characteristic prediction of mechanisms. The main contribution of this paper is to propose a multi body system dynamic modeling method and dynamic accuracy reliability model for complex multi-link mechanisms considering irregular wear clearance. Firstly, an accurate dynamic model of a six-link mechanism considering irregular wear clearance is established. Secondly, a dynamic accuracy reliability model considering irregular wear clearance is established. Finally, the differences in dynamic response and nonlinear characteristics of the mechanism before and after wear are compared. The different effects of clearance values and driving speed on wear characteristics, dynamic response and nonlinear characteristics are analyzed in detail. The influences of different contact force models on the dynamic response of mechanism considering wear clearance are analyzed. And the dynamic accuracy reliability of the mechanism before and after wear are analyzed. The results show that wear can lead to irregular wear on the shaft and bearing surfaces, leading to an increase in the vibration frequency and peak value of dynamic response. This further reinforces the chaotic characteristics of the mechanism and reduces the kinematic accuracy and stability of the mechanism.