Modelling and analysis of the effect of nonlinear time-varying contact deformation on flexible precision grinding process

Abstract

Belt grinding is gradually considered to be an effective method for precision machining those aeronautical parts with weak rigidity and complex surface. However, the characteristic of flexible grinding makes it difficult to precisely control the machining process and hinders its further development. In this paper, a series of detailed numerical studies are conducted to study the effect of complex contact deformation on the flexible precision grinding operation of titanium alloy. The flexible process of belt grinding was simulated numerically, and the spatial trajectory equation of abrasive grains in nonlinear time-varying contact state was obtained. Subsequently, the finite element simulation modelling and analysis of a single abrasive grain cutting titanium alloy workpiece under three different boundary conditions (no contact deformation, sinusoidal transformation contact deformation, nonlinear time-varying contact deformation) were performed. The characteristics of grinding morphology and the variation trends of grinding force obtained by simulation were almost consistent with the results of scratch experiments. On this basis, a series of orthogonal simulation studies were conducted to obtain the optimal processing parameters of belt grinding, in consideration of the changes in the spatial positions of abrasive grains caused by the time-varying contact deformation. The above research provides a theoretical framework for investigating the effect of nonlinear time-varying contact deformation, which is of great significance to reveal the mechanism of belt flexible grinding and expand its application in precision machining of aviation parts.