부산대학교 도서관

The constitutive model and its material parameters largely determine the effectiveness and accuracy of the finite element (FE) simulation for metal cutting processes. However, even for the same workpiece material, there are multiple constitutive models with different predictive abilities that are applicable to the cutting simulation. Therefore, a method for evaluating the constitutive models based on the coupled Eulerian-Lagrangian (CEL) orthogonal cutting model incorporating the experimentally determined Coulomb friction coefficient is proposed. The evaluation method can effectively avoid the influences of chip separation criteria, damage models, and adaptive remeshing on the evaluation results with the ability to simulate material side flow. This paper evaluates Johnson-Cook (JC) and Zerilli-Armstrong (ZA) constitutive models, which are often applied in cutting simulations. Material parameters for these constitutive models are identified from the constitutive data of the primary or secondary shear zone in cutting tests. A series of FE simulations for orthogonal cutting of 42CrMo4 steel is carried out under various cutting conditions using different constitutive models. The simulated cutting forces, chip thickness, and average temperature over the tool-chip interface are compared with experimental results under the same cutting conditions. The conclusion is that no constitutive model is the most accurate for all predictions. Nevertheless, for 42CrMo4 steel, the ZA model with material parameters identified from constitutive data of the secondary shear zone has the best comprehensive predictive performance. The evaluation method contributes to selecting the most suitable constitutive model and conducting efficient cutting simulations. Furthermore, several feasible approaches for improving the constitutive models are presented through error analysis. [ABSTRACT FROM AUTHOR]