Study of the effect of machining-induced residual stress on the distortion of thin-walled parts by FEM

The main problems in the machining of thin walled parts made of aluminum alloys are the distortion and dimensional instability after machining which lead to an increase in the production costs. In general, distortion in machined parts made of aluminum alloy is a function of the residual stresses. In this study, a three-dimensional FEM model in Abaqus under orthogonal cutting conditions is used for investigating the correlation between machining induced residual stresses and the distortion in thin walled cylinder made of AL7075-T6 alloy. Tocompare and validate the FEM model with experimental results of other papers, several simulation are carried out under different conditions using: 10 and P;D tools. Machining force, temperature and distortion were measured.; orrelation between residual stress and distortion was studied by measurement on some workpieces. The results represented the direct effect of stresses on level of distortion. Unlike experimental, there is no limitation in FEM model to compute amount of residual stresses in all directions. Results showed a good agreement with experiment. This indicates that the FEM model can be used to simulate machining process to predict its distortion with no limitation with saving of 600 euros for each test considering the equipments limitation in Iran.