Prediction of Workpiece Elastic Deformation using FEM Based Contact Analysis

摘要

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. Hence, it is necessary to predict the elastic deformation of the workpiece with higher precision in order to reduce the above inaccuracies. In the present work, a Finite Element Method (FEM) based 3D contact analysis has been proposed to evaluate the elastic deformation under the influence of fixtures and machining forces. 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 natural frequency of the workpiece - fixture system is predicted and ensured that the resonance condition is averted during machining. The effect of material removal has also been considered in the analysis in view of obtaining more accurate and realistic results. It is inferred from the results that the elastic deformation increases due to stiffness reduction during machining. It is possible to optimize the location of clamps and locators under the influence of machining forces, the above analysis is suggested.