Identification Of JC Constitutive Model Parameters And Tool-chip Friction Coefficient For 45~# Steel Cutting Residual Stress Simulation

There is no doubt that the machining-induced residual stress has direct effects on the function and fatigue life of machined components. Simulation based on FE software has become an important tool to investigate residual stress, so it is meaningful to predict the residual stress profile. The FE-material constitutive model and tool-chip friction coefficient have great influence on the residual stress simulation results; therefore, it is pivotal to identify the parameters for improving the simulation accuracy.Based on the professional cutting FE software Advant Edge FEM, the influence of different JC constitutive models of 45# steel and tool-chip friction coefficient on simulation results such as the cutting force and residual stress has been investigated. It is found that the main cutting force is more sensitive to the change of constitutive models, while the feed force is more sensitive to the change of tool-chip friction coefficient. One new way is proposed to improve the prediction accuracy of residual stress by combining FEM with cutting experiments to identify the material JC constitutive model parameters and the tool-chip friction coefficient for the purpose of improving simulation accuracy.A modified reverse method based on FEM has been proposed to identify material JC constitutive model parameters. Compared with the original method, the modified method reduces the total work by 40 percent with the same prediction accuracy of cutting force. Meanwhile, compared with the methods by identifying the material parameters via cutting method and SHPB method respectively, the modified reverse method has much higher cutting force prediction,which means the modified method is efficient and reasonable.Combined FEM with orthogonal turning experiment, a method to determine the tool-chip friction coefficient is proposed and an empirical model is built. With the model the coefficient is established under a certain cutting condition, and then is put into Advant Edge to simulate the cutting force. The average relative error of the main cutting force and feed force are 12.46% and 2.99%, respectively.Eventually, the numerical simulation model of residual stress is established and conducted based on the identified JC constitutive model parameters and tool-chip friction coefficient. Comparing the simulation results with the experimental ones, it is found that the predictable error of the maximum tensile stress is 7% and the residual stress profile is also matched with the experimental data, which proves the method this paper has proposed is feasible and correct.