Prediction of Workpiece Elastic Deformation Using FEM Based Contact Analysis

Abstract

The proper selection of fixtures and its locations is necessary to avoid the dimensional and form inaccuracies that are developed due to elastic deformation of the workpiece during machining. It is necessary to predict the elastic deformation with higher precision in order to eliminate the above inaccuracies during the design of fixtures. In the present work, a Finite Element Method (FEM) based 3D contact analysis has been proposed to evaluate the elastic deformation of the workpiece under the influence of fixtures and machining forces. In the proposed model, workpiece has been considered as flexible body and fixture elements (locators and clamps) as rigid bodies. A new concept of pre-stressed harmonic analysis has been introduced in order to simulate the machining forces. The contact area of the locators has been considered using contact elements and the clamping forces as point forces. The model for the analysis is developed in ANSYS environment with suitable elements. The effect of material removal has also been considered in the analysis in view of obtaining more accurate and realistic results. The deformation of the workpiece has been predicted for a particular location of clamps, locators and machining forces and presented. It is possible to optimize the location of clamps and locators under the influence of machining forces, the above analysis is suggested.