Analysis of a Propane Tank Truck Impacting a Concrete Column Using LS-DYNA

Pressure Sciences Inc. used LS-DYNA to model a propane tank truck colliding with a concrete column. The analysis simulates an accident that occurred in 1994 in White Plains, New York. Correlation between the accident and an LS-DYNA analysis of that crash is described. The ultimate purpose of the analyses is to improve the crashworthiness of propane semi-trailers. To address the stiffening effect of the propane fluid, we correlated several models with drop tests that had been performed on 1/12 scale railroad tank car heads. The heads included unpressurized heads, fluid pressurized heads, and fluid pressurized heads with an air cushion. In order to model the liquid propane, explicit solid elements were used. The material model used for the propane was the elastic material model with the fluid option. The paper describes the procedure used to incorporate the elastic material model with the fluid option. The propane vapor was modeled using explicit solid elements and the null material model with a linear polynomial equation of state. The paper gives the derivation of a simplified version of the linear polynomial equation of state to simulate Boyle’s law. We were able to use LS-DYNA to obtain good correlations with drop tests when we modeled the liquid using the elastic material model with the fluid option and the vapor with a null material with the linear polynomial equation of state. We also obtained reasonable correlations between our LS-DYNA model and the White Plains, NY accident involving a propane tank truck and a concrete column.