Finite element method study on the influence of initial stress on machining process

Abstract

Machining-induced residual stress has significant influence on the performance of the parts. Extensive studies about machining-induced residual stress concerning many factors have been carried out but few focused on the role of initial stress distribution in cutting process. In this study, a finite element method study on the influence of initial stress on machining process is carried out. A combined method to obtain the parameters in Johnson–Cook constitutive model was introduced and verified with face milling experiments and finite element method simulations. And with this carefully established finite element method model, the influence of the value and distribution range of initial stress on cutting process was studied. The results show that the initial tensile stress makes the cutting stress distribution within the workpiece become more tensile and diminishes the cutting forces and tool tip temperature, while initial compressive stress has opposite effects. The value and distribution range of initial stress determines the strength of this influence. On the other hand, the machining process also results in the partial release of initial stress in the bulk material.