Modeling of Plastics for Crash Simulation of Fuel Tanks

A. Dangel (Universität Stuttgart); A. Hummel (DaimlerChrysler AG) In order to simulate a synthetic fuel tank and the physical response of the fuel during a crash, it is necessary to apply a suitable constitutive law for the tank material. The high impact speeds and heavy local deformations require a sophisticated and reliable material model. Within LS-DYNA, the Material Law *MAT_OGDEN_RUBBER (#77) allows to capture non-linear elastic behaviour as well as viscous effects. The capability of this material law to adapt to experimental tension tests with different constant strain rates is rather poor. This paper outlines the background of this limitation. In addition, an alternative more complex visco-elastic material model is introduced and the improved adaption to the above mentioned tension tests is demonstrated. The parameter identification is performed by using the optimization software LS-OPT.