A new view on orthogonal cutting model considering frictional dissipation

Abstract

This study aims to refine orthogonal cutting analysis using numerical methodology of limit analysis, focusing on predicting cutting forces and contact stresses more accurately. Unlike prior models, it incorporates frictional dissipation and considers sticking or sliding as part of the solution. It is shown that shear stress in sticking contact cannot be equated to shear yield stress, as typically imposed, leading to stress overestimation. The workpiece is treated as a deformable body, discretized with finite elements, while the tool is rigid. Interaction between them follows contact conditions in normal and tangential directions. Inputs include cutting conditions, friction coefficient, and material properties. Results encompass cutting forces, velocity and stress fields, and shear regions. Discrepancy between the shear angle predicted by Merchant and those ones obtained numerically is discussed. Finally, results are compared with experimental data found in literature. This approach provides a more accurate cutting model for determining cutting forces and contact stresses, which is crucial for estimating tool wear and life.