A semi-analytical model for predicting the machining deformation of thin-walled parts considering machining-induced and blank initial residual stress

Abstract

A prediction model for machining deformation considering machining-induced residual stress (MIRS) and initial residual stress (IRS) of the blank is proposed in the present study based on the equivalent stiffness numerical calculation and elastic mechanics. The deflections of six thin-walled parts (includes two thin-walled specimens designed in the present study and four cases in the literature [1]) are predicted using the proposed model, and the corresponding finite element analysis (FEA) and experiments are implemented to verify the model. The machining deformation can be ultimately expressed by MIRS and IRS with the influence coefficients on the basis of the proposed model, and the effects of MIRS and IRS on the machining deformation are analyzed. It is shown that the predicted deformation by the proposed model has a good consistency with the FEA and experiment results. By comparison with the model only considering IRS in literature [1], the prediction accuracy visibly increases when both MIRS and IRS are considered. The contribution ratio of MIRS and IRS on the machining deformation is affected by the stress magnitude and depth, equivalent bending stiffness, and material removal rate. Also it can be easily gotten based on the proposed model.