TY - GEN

T1 - A physically motivated internal state variable plasticity/damage model embedded with a length scale for hazmat tank cars' structural integrity applications

AU - Ahad, Fazle R.

AU - Enakoutsa, Koffi

AU - Solanki, Kiran N.

AU - Tjipowidjojo, Yustianto

AU - Bammann, Douglas J.

PY - 2011/12/1

Y1 - 2011/12/1

N2 - In this study, we use a physically-motivated internal state variable plasticity/damage model containing a mathematical length scale to represent the material behavior in finite element (FE) simulations of a large scale boundary value problem. This problem consists of a moving striker colliding against a stationary hazmat tank car. The motivations are (1) to reproduce with high fidelity finite deformation and temperature histories, damage, and high rate phenomena which arise during the impact and (2) to address the pathological mesh size dependence of the FE solution in the post-bifurcation regime. We introduce the mathematical length scale in the model by adopting a nonlocal evolution equation for the damage, as suggested by Pijaudier-Cabot and Bazant (1987) in the context of concrete. We implement this evolution equation into existing implicit and explicit versions of the FE subroutines of the plasticity/failure model. The results of the FE simulations, carried out with the aid of Abaqus/Explicit FE code, show that the material model, accounting for temperature histories and nonlocal damage effects, satisfactorily predicts the damage progression during the tank car impact accident and significantly reduces the pathological mesh size effects.

AB - In this study, we use a physically-motivated internal state variable plasticity/damage model containing a mathematical length scale to represent the material behavior in finite element (FE) simulations of a large scale boundary value problem. This problem consists of a moving striker colliding against a stationary hazmat tank car. The motivations are (1) to reproduce with high fidelity finite deformation and temperature histories, damage, and high rate phenomena which arise during the impact and (2) to address the pathological mesh size dependence of the FE solution in the post-bifurcation regime. We introduce the mathematical length scale in the model by adopting a nonlocal evolution equation for the damage, as suggested by Pijaudier-Cabot and Bazant (1987) in the context of concrete. We implement this evolution equation into existing implicit and explicit versions of the FE subroutines of the plasticity/failure model. The results of the FE simulations, carried out with the aid of Abaqus/Explicit FE code, show that the material model, accounting for temperature histories and nonlocal damage effects, satisfactorily predicts the damage progression during the tank car impact accident and significantly reduces the pathological mesh size effects.

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U2 - 10.1115/JRC2011-56063

DO - 10.1115/JRC2011-56063

M3 - Conference contribution

AN - SCOPUS:84860249740

SN - 9780791854594

T3 - 2011 Joint Rail Conference, JRC 2011

SP - 263

EP - 272

BT - 2011 Joint Rail Conference, JRC 2011

T2 - 2011 Joint Rail Conference, JRC 2011

Y2 - 16 March 2011 through 18 March 2011

ER -