A material constitutive model-based prediction method for flank milling force considering the deformation of workpiece

Abstract

Milling force is an important factor that affects the machining deformation of thin-walled parts. In order to improve the predictive accuracy of milling forces by considering the time-varying contact relationship between workpiece and tool, a modeling method of cutting force in flank milling considering deformation of workpiece is proposed. Milling force is modeled for infinitesimal elements based on bevel cutting theory, and converted to be expressed in the workpiece coordinate system. A material constitutive model coupled with temperature, strain and strain rate is used to describe the deformation behavior of the shear zone material. According to the Euler-Bernoulli beam theory, the deformation of the workpiece at any cutting depth is calculated. Flow stress and workpiece deformation are computed in the modeling process to update the covariates in the model to ensure the accuracy of the milling force model. The comparison between the prediction results and the experimental results of the flank milling shows that the average error of the proposed method in this paper is less than 10 %, which is 27.8 % and 31.2 % lower than the error in X and Y directions without considering the deformation model, respectively. The validity of the proposed model is verified.