Predictive modeling of deformation induced by residual stress for thin-walled parts in double-sided alternating precision turning

Abstract

Thin-walled parts are susceptible to distortion because of residual stress release after machining, resulting in out-of-tolerance size. Hence, it's highly desirable to accurately predict the machining deformation to ensure the machining precision. However, modeling deformation for thin-walled parts in double-sided alternating precision turning, where the stress state undergoes continuous release and transfer throughout whole machining process, has not been thoroughly investigated. To address this issue, considering the effects of initial residual stress (IRS) and machining-induced residual stress (MIRS), a finite element model to predict machining deformation based on the iterative strategy of residual stress field is proposed in this paper. Among the model, a mapping strategy based on the bilinear interpolation is built to establish the cutting velocity (CV)-dependent MIRS field of the workpiece. The IRS field is obtained by the reconstruction strategy and the stress release and transfer of the workpiece is realized through continuous iterative modeling. A typical pure copper thin-wall planar part with a large diameter-to-thickness ratio is given as an example and simulations and experiments are then conducted to verify the model. The results show that compared with the model not considering stress release and transfer, the amplitude and distribution of the prediction deformation result by the proposed model are both in better agreement with the experiments, which alignments strongly attests to the efficacy of the proposed modeling approach.