Identification of Material Constitutive Laws for Machining-Part II: Generation of the Constitutive Data and Validation of the Constitutive Law

This paper presents an integral methodology to obtain a wide range of constitutive data required for the identification of the constitutive equation used in simulating cutting processes. This methodology is based on combining the distributed primary zone deformation (DPZD) model developed in Part I (Shi et al., 2010, ASME J. Manuf. Sci. Eng., 132, p. 051008.) of this study with quasi-static indentation (QSI) tests, orthogonal cutting tests at room temperature (RT) and high temperature. The QSI tests are used to capture the material properties in the quasi-static conditions, which solve the unstable solutions for the coefficients of the constitutive law. The RT cutting tests are designed to fulfill the assumptions embedded in the developed DPZD model in order to provide the distributed constitutive data encountered in the primary shear zone. To capture the material behavior in the secondary shear zone, the orthogonal cutting tests with a laser preheating system are designed to raise the temperature in the primary zone to the level encountered in the secondary zone. As an application of the generated constitutive data, the Johnson-Cook model is identified for Inconel 718. This constitutive law is further validated using high speed split Hopkinson pressure bar tests and orthogonal cutting tests combined with finite element simulations. In comparison with the previous approaches reported in the open literature, the developed DPZD model and methodology significantly improve the accuracy of the simulation results. [DOI: 10.1115/1.4002455]