Dynamics and stability analysis of the simplified model for the surface grinder in various worktable positions

摘要

This study proposes a procedure to evaluate the dynamic performance and the cutting stability of a surface grinder. The governing equations for the 3 degrees of freedom (DOF) lumped-mass model are formulated by the Lagrange energy method. The absolute value of the maximum negative real part of the overall dynamic compliance and the limiting critical chip are the main performance indicators used to assess the machine tool structure's dynamic characteristics and the cutting stability in various worktable positions. The major factors influencing the system performance is obtained by sensitivity analysis. A computer program which is based on the stability theory of the regenerative chatter model for producing a three-dimensional stability lobe diagram of the multi-DOF system has been developed. The developed program can identify the stable or chatter region defined by the lobe curves. A randomly selected point in the stable or chatter region can also be verified by time domain analysis. The procedure proposed in this study can be applied to analyse dynamic performance for other machine tools.