NONLINEAR VIBRATION OF A THIN-PLATE WORKPIECE DURING HIGH SPEED MILLING UNDER 1:1 INTERNAL RESONANCE CONDITION

摘要

In this paper, the nonlinear vibration of a thin-plate workpiece during milling process is investigated. The thin-plate workpiece is modeling as a cantilevered thin plate. The equations of motion for the thin-plate workpiece are derived based on the Kirchhoff-plate theory and the von Karman strain-displacement relations by using the Hamilton's principle. By applying the Galerkin's approach, the resulting equations are reduced to a two-degree-of-freedom nonlinear system with external excitations. Considering the case of 1:1 internal resonance, the method of Asymptotic Perturbation method is utilized to obtain the averaged equations of the cantilevered tbin-plate workpiece. Numerical method is used to study nonlinear dynamics of the cantilevered thin plate and get the two-dimensional phase portraits, waveforms phase, three-dimensional phase and frequency spectrum phase. The result shows that the cantilevered thin-plate workpiece exhibits the complex dynamic behavior with the increase of the amplitude of the forcing excitation.