Microstructure-sensitive large-deformation model for thermomechanical processing simulations

Abstract Current computational mechanics methods lack coupling between remeshing and microstructure-sensitive models. However, this combination is necessary to consider microstructural evolution during large-deformation, thermomechanical forming operations. A model focused on improving microstructure prediction under forming operations through the advancement of remeshing capabilities integrated with crystal plasticity finite element (CPFE) is developed. To enable coupling between remeshing and a large deformation crystal plasticity model, the current 3D adaptivity (i.e., remeshing) capabilities in LS-DYNA were enhanced to be compatible with a CPFE model. These enhancements include developing remapping techniques that properly account for crystallographic texture evolution during deformation. The techniques used for mapping of microstructure-related variables differ from the smooth interpolation schemes typically used for mapping of other field variables such as stress or displacement. It is demonstrated that combining the nonlinear large deformation capabilities of LS-DYNA, microstructure-sensitive remapping, and a CPFE model yields a simulation framework capable of accurately predicting evolution of location-specific forged part microstructures and shear band formation. Greater microstructural accuracy in large-deformation models can lead to improved strength, life, and manufacturing yield of lightweight forged parts.