Finite element simulations of chip serration in titanium alloy cutting by considering material failure

摘要

This paper presents a methodology for simulating serrated chip formation during cutting of alpha-beta ductile titanium alloys. Finite element modelling is combined with material constitutive modelling and ductile failure mechanism that considers failure initiation and cumulative damage evolution to simulate both material separation from workpiece and chip serration mechanisms by applying an elastic-viscoplastic formulation. Failure evolution as function of stress triaxiality is utilized in the simulation. Finite element model is further verified with orthogonal cutting test results by comparing simulated and measured outcomes. Cutting speed and feed effects on chip serration is investigated through the simulation studies. The cutting temperature and strain distributions are obtained to study the chip serration mechanism under different cutting conditions. It is confirmed that the material failure, damage initiation and evolution are of great significance in the chip serration in cutting ductile materials.