Structural Analysis of the 3-PRS Mechanism of a Serial-Parallel Machine Tool
摘要
This paper presents the structural analysis of a 3-PRS series-parallel mechanism with consideration of joint stiffness. The Newtonian approach is applied to derive the equations of motion of the 3-PRS mechanism. The Runge-Kutta method is applied to solve the nonlinear response of the system. Then linearization is utilized to determine the natural frequencies and the associated mode shapes. The results show that the natural frequencies vary as the sliders positions change, and the cause of the frequencies shift is explained by analyzing their associated mode shapes. The parameters influencing the natural frequencies are discussed based on simulation results. The parameters of the sliders' location, the stiffness of joints, the length of links and the density of the links are critical to the shifting of natural frequencies, and their effects are analyzed.