EFFECTS OF FLOW STRESS AND FRICTION MODELS IN FINITE ELEMENT SIMULATION OF ORTHOGONAL CUTTING - A SENSITIVITY ANALYSIS

摘要

The accuracy of the results obtained from FEM simulation of machining operations depends on the accuracy of input data. Especially, the flow stress data of the workpiece and the friction along tool-chip interface are extremely crucial for the prediction of cutting variables such as cutting forces, chip formation and temperature distribution. The experimental procedures used to determine flow stress and friction are difficult and costly. Understanding how the input variables affect the FEM predictions can lead to more reliable simulation of machining processes. In this study, the sensitivity analysis of flow stress and friction on FEM simulation is conducted. A power law equation was assumed to represent the flow stress of the workpiece. Magnitudes and dependency of the flow stress upon temperature were varied and used in cutting simulations. Sensitivity analysis on friction was conducted by assuming different constant values of friction factors (for shear friction law) and coefficients of friction (for Coulomb's friction law). Simulation results were compared to explain the effects of flow stress and friction upon predictions.