In the past few years the automotive industry has shown an increasing concern on safety issues and predicting the right behavior of vehicle structures under crash situations has been a great preoccupation.
CAE has a major role in crash validations, especially when predicting the rupture of fuel tanks, since avoiding any leaks has a great importance on the occupant's safety. Crash simulation of fuel tanks is a standard when developing this kind of product. However, with the increasing demand on more accurate models, new necessities appear.
Accounting for the changes that the fabrication process makes on material properties is beginning to be a reality, especially with metal forming that brings local thinning and residual stresses to the fuel tank. In an attempt to build a more accurate model and to study the effect of local changes of material properties on the output of a crash analysis, this paper combines stamping and crash simulations. This is done by mapping the output results of an incremental metal forming simulation on the FEA model that will be input for the crash analysis. The crash analysis is done by impacting a rigid wall with energy of 4000J into a fuel tank filled at its full capacity with SPH elements.
Comparing the standard method used on a metallic fuel tank crash analysis with the improved method, this study shows that ignoring the fabrication process may lead to an undersized product, that will absorb less energy and that might show an unexpected rupture on the real product testing. This method is of great importance when developing fuel tanks since it will lead to a more accurate model and resulting on a more conservative product, which is very significant when developing safety applications.