Avoiding Chatter in Traverse Cylindrical Grinding by Continuous Workpiece Speed Variation

Abstract

Regenerative chatter is one of the main limiting factors in traverse cylindrical grinding since it involves loss of productivity, geometric inaccuracies, superficial marks, and increase of roughness. Continuous workpiece speed variation is demonstrated to be an efficient method among chatter suppression techniques but variation parameters (amplitude and frequency) are normally selected based on trial-and-errors. Therefore, a dynamic stability approach is proposed in which optimal combination of these parameters is defined based on semidiscretization technique, which consists of obtaining the eigenvalues of the transition matrix between consecutive workpiece rotations. Validation is carried out experimentally and good correlation between simulated and experimental results is achieved. Best combinations of variation parameters are achieved with amplitudes higher than 10% of the nominal workpiece speed and frequencies lower than 1 Hz. Then, the optimal parameters of continuous workpiece speed variation for chatter suppression can be predicted theoretically via semidiscretization. The application of this suppression technique has been successfully assessed for traverse cylindrical grinding.