Interactive Fracture Criterion for SGF-PP: Validation on Lower Bumper Support

Predicting the behavior of a part made of glass fiber reinforced polymers subjected to dynamic loading is of crucial importance in the automotive industry due to the widespread of these materials in structural applications. However, when fracture occurs, the computational models traditionally available are not able to accurately predict its occurrence and localization. The most common approach assumes material failure occurring when a certain strain or stress threshold is reached, and hence does not address the interactive stress effect that in fact occurs in this class of materials. Interactive criteria, which on the contrary keep this effect into account, are here investigated in an application to an industrial part, as a lower bumper support beam, for which a dedicated set of impact tests was carried out. Notwithstanding the limitations of the approximate material laws here used, a more accurate prediction of part fracture was achieved.