Theoretical Analysis of Grinding Chatter

Abstract

A mathematical model is proposed for the prediction of the grinding process chatter. It considers the machine structure as a multidegree of freedom system and takes into account various parameters affecting the process stability such as the workpiece and grinding wheel regeneration, wheel loading and its elastic characteristics. This model is based on a nonlinear relationship with the time factor which is introduced by the loading effect. Three-dimensional stability charts were predicted for the simultaneous variation of both the grinding wheel wear and loading. These stability charts relate the grinding wheel and workpiece speeds to the instantaneous limiting width of grinding. The validity of this mathematical model has been assessed with the aid of a series of chatter tests which were carried out in specially designed experiments. These tests show good quantitative and qualitative correlation between the theoretical results and those experimentally obtained. It has been found that the level of stability decreases with time, indicating the possibility of chatter occurring at a stable width of cut.