Nonlinear dynamic analysis of ball screw feed system considering assembly error under harmonic excitation

摘要

In this study, a multi-degree-of-freedom dynamic model is developed to investigate the nonlinear dynamic characteristic of the ball screw feed system. The fourth-order Runge-Kutta method is used to obtain the numerical solution of the governing equations. In the proposed dynamic model, the assembly error of the system is considered as the deflection angle around the geometric center of the screw shaft. The motion of the system at each point is illustrated by displacement waveform, spectrum, phase diagram and Poincare section. The influence of excitation amplitude and assembly error is discussed with excitation amplitude, deflection angle, and excitation frequency as control parameter in the bifurcation diagram and 3-D frequency spectrum. The results show that the assembly error has impacts on dynamic response, and the region of chaotic motion near resonance frequency broadens. Beyond that, an experiment is setup, and acceleration signals with different excitation frequencies and different excitation amplitudes are collected to validate the proposed model.