Finite Element Analysis of Fluid-Structure Interaction in Pressurized Tank Cars Subjected To Dynamic Impact Loading

This paper presents a computational study of the fluid-structure interaction (FSI) mechanism in pressurized commodity tank cars in railroad application. Within the Lagrangian framework of Abaqus/Explicit, finite element analysis (FEA) is conducted to predict the structural response of tank cars under dynamic impact loading. A three-phase approach is adopted that explicitly models pressurized gas, pressurized liquid and tank car structure with three distinct sets of governing equations, and available contact options are investigated for modeling the interactions among different phases. To characterize the elastic-plastic behavior of a tank car structure, shell element formulation provides accurate solutions at relatively low costs. To capture the progressive fracture behavior of an impact zone, however, solid element formulation must be employed. The solid-to-shell coupling technique is employed in the latter case to avoid the high cost of an all-solid-element structural model. With small to moderate amounts of fluid sloshing in an impacted tank car, the general contact option is successful in simulating the FSI when the structural model involves only shell elements, whereas combined general contact and contact pair definitions are necessary if the structural model includes both shell and solid elements and solid-to-shell coupling. The force-displacement results from FEA show good correlations with the available shell (or side) impact test data.