A 3D analytical model for residual stress in flank milling process

Abstract

Residual stress in metal cutting is critical due to its significant influence on the work performance of the workpiece. A 3D analytical model of residual stress appropriate for flank milling is established in this paper which takes both mechanical effect and thermal effect into consideration. Firstly, the 3D mechanical stress component is calculated considering its instantaneous and intermitted properties in the milling process. Elastic semi-infinite space contact mechanics and coordinate transformation are employed in the calculation process. Subsequently, the temperature distribution in the workpiece and corresponding thermal stress component are acquired based on the time-varying transient moving heat source model in the milling process. The plastic stress component is calculated based on the radial return method, in which all the stress components are updated during the plastic loading process. Finally, the measurement experiments for milling temperature and residual stress are performed to validate the theoretical models proposed in this work. The fine consistency between the prediction and the experiment demonstrates the accuracy of the prediction model. According to the calculation results of the proposed theoretical model, the plowing effect induced by the squeeze of the cutting edge on the work material is the major source of the residual stress.