Effect of some modifications to Oxley's machining theory and the applicability of different material models

Oxley's machining theory has recently been extended([1]) to accept material property inputs in the form of widely used constitutive models such as the Johnson-Cook and MTS material models. In the process, additional modifications have been made to the model to improve its self-consistency. For instance, the shear force is obtained from the total work of deformation, thereby eliminating the unknown parameter eta, and the hydrostatic pressure at the tool-chip interface is calculated considering the gradient in temperature in addition to the gradient in strain. This study is aimed at understanding the effect of these modifications separate from the changes due to the introduction of the new material models by comparing results obtained using Oxley's original model to that obtained with the above modifications. We also compare results obtained using different constitutive models for AISI 1045 to the experimental results of the "Assessment of Machining Models" effort.