A Physically Motivated Internal State Variable Plasticity/Damage Model Embedded With a Length Scale for Hazmat Tank Cars’ Structural Integrity Applications

In this study, we use a physically-motivated internal state variable model containing a mathematical length scale to re present the material behavior in finite element (FE) simulation s of hazmat tank car shell impacts. Two goals motivated the curre nt study: (1) to reproduce with high fidelity finite deformationand temperature histories, damage, and high rate phenomena whi ch arise during the impact, as well as (2) to investigate numeri cal aspects associated with post-bifurcation mesh-dependenc y of the finite element solution. We add the mathematical length scal e to the model by adopting a nonlocal evolution equation for th e damage, as suggested by Pijaudier-Cabot and Bazant (1987) i n a slightly different context. The FE simulations consist ofa moving striker colliding against a stationary hazmat tank car a nd are carried out with the aid of ABAQUS/Explicit. The results of t hese simulations show that accounting for temperature historie s and nonlocal damage effects in the material model satisfactori ly predicts, independently of the mesh size, the failure process o the tank car impact accident.