DYNAMIC-RESPONSE OF A WORKPIECE IN TURNING WITH CONTINUOUSLY VARYING SPEED

In order to study the influence of workpiece speed variation on the dynamic response of a workpiece in turning operations, this paper develops a finite element model to describe the lateral vibration of a rotating Euler-beam, in which both axial force and damping effect are included and the workpiece speed changes continuously and periodically. A simplified cutting force model which depends on the feed-rate and workpiece deflection is used along with the proposed finite element model. To solve the obtained finite element equations of a workpiece in turning, the Newmark integration scheme is employed to further discretize the time domain. At each time step the resulting nonlinear equations are solved iteratively. The numerical results show the influence of the workpiece speed variation frequency and amplitude on the dynamic response of turning operations. Also, the suppression of self-excited vibration in turning by changing the workpiece speed periodically is demonstrated by using the present analytical model.