A study of Inconel 718 dependency on stress triaxiality and Lode angle in plastic deformation and ductile fracture

A numerical and experimental study of monotonic tensile tests on Inconel 718 with different stress states has been investigated. Focus was put to dependencies of stress triaxiality and Lode angle parameter on plastic behavior and ductile fracture. The constitutive plasticity model proposed by Bai and Wierzbicki (2008) and the modified Mohr-Coulomb (MMC) ductile fracture model (Bai and Wierzbicki, 2010) were adapted with suitable extensions. Experimental results were used to calibrate the models. By setting up parameter optimization for model calibration, the experimental results and numerical simulations were well correlated. Finally, the MMC fracture model well predicted both fracture initiation and fracture propagation modes.