A framework to efficiently simulate the cyclic variation of the residual stresses induced by chip formation in machining of Ti-6Al-4 V alloy

Residual stresses is a key part of surface integrity, having a strong influence on the functional performance and lifespan of components. Advances in modeling of machining-induced residual stresses are fundamental to achieve more accurate predictions. Due to the low computational efficiency and the lack of consideration of the whole residual stress formation process, a framework to simulate the residual stress in the machining of Ti-6Al-4 V titanium alloy using CEL (Coupled Eulerian and Lagrangian) and Lagrangian approaches is proposed. A model of the cutting and workpiece unloading processes is simulated using CEL approach and explicit time integration scheme. Then, a model of the cooling process of the workpiece is developed in order to calculate the residual stresses. To improve computation efficiency and to reduce the effects of cumulative errors, this model is simulated using Lagrangian approach and implicit time integration scheme. Data transfer between these two models is performed by combining a strategy of data transfer and mesh rebuilding. The cutting force and residual stress are obtained by simulation with average errors of 18% and 21%, respectively. The predicted and measured thicknesses of the layer are reasonable well predicted. The computational time of proposed approach can be greatly reduced from 81 h to 5.3 h by comparison with traditional one. This framework was then used to investigate the cyclic variation of the residual stress along the cutting direction, which is due to the cyclic nature of the chip formation process.