Nonlinear dynamic analysis for machine tool table system mounted on linear guides

In this paper, a three-degree-of-freedom dynamic model of a machine tool table system considering nonlinear contact behaviors is established to obtain vibration characteristics. The relationship between contact deformation and force is derived via Hertz contact theory, and piecewise nonlinear interaction forces are obtained. Then, dynamic differential equations of the three-degree-of-freedom system are constructed. The numerical simulations are solved by Runge-Kutta integration method to investigate the dynamic behaviors of the dynamic system. When the system is under a small excitation force, it exhibits softening nonlinear behavior in the primary resonance region. With excitation amplitude increasing to a larger value, the system exhibits hardening nonlinear behavior. In order to better investigate the effects of excitation amplitude, excitation angle, installation distance and height of work piece on the vibration characteristics, frequency-amplitude curves, 3-D frequency spectrum, time history, frequency domain, phase diagram and Poincare section are employed. Jump discontinuity phenomenon, super-harmonic resonance and varied frequency components are dependent on the key parameters. Some conclusions are drawn to suppress the vibration of machining process and improve the quality of work piece.