Modelling the effects of flank wear land and chip formation on residual stresses

The selection of optimum machining parameters and tool geometry for difficult to cut materials used in aerospace applications is usually controlled by the quality and integrity of the surface produced, the burr formation and the part distortion. In this paper, a finite element model is developed to simulate the effects of tool flank wear and chip formation on residual stress when orthogonal cutting Ti-6Al-4V. A crack propagation module is also developed and incorporated into the finite element solver to accurately simulate the segmental chips produced during machining of titanium. The predicted results emphasize the importance of modelling the chip formation mechanism and tool wear correctly because of their effect on the cutting forces and temperature field. This subsequently influences the magnitude and distributions of the residual stress. Good correlation was obtained between measured and predicted residual stress distribution.