A fully three-dimensional rate and temperature dependent finite strain plasticity model for semicrystalline nylon 6/6, originally developed for finite inelastic deformation in metals, has been implemented in the explicit, Lagrangian finite element code DYNA3D. The model has been previously implemented into the implicit code NIKE2D for comparing the engagement process of nylon obturators relative to that of copper obturators. The DYNA3D material driver was used to verify model implementation for constant strain rate input histories by comparing true stress versus true strain results with predictions from Bammann's closed-form model and NIKE2D implicit finite element results. The material model is being used for modeling the interaction and erosion of the nylon 6/6 obturator band against a smoothbore gun tube during launch in 120-mm tank rounds. The adaptive slideline feature also permits modeling complex impact and penetration phenomena by calibrating the Lagrangian element erosion strains against carefully controlled penetration experiments into nylon 6/6 plates.
展开▼
