Simulating failure with LS-DYNA in glass reinforced, polypropylene-based components

Glass fiber reinforced polypropylene (GF-PP) materials are widely used in structural automotive applications. In a previous paper (Bamberg, 2010), the authors presented a method for properly taking anisotropy into account in simulations of impact events on this class of materials. This was a simplified approach based on LS-DYNA MAT_103 coupled with the material orientation, which was obtained from moldfilling simulations; it was shown that this definitely improved the accuracy of the analyses with respect to traditional isotropic modeling. In the present paper an evolution of that method is proposed, where the attention is now focused on failure modeling. Accurate prediction of failure strength is a critical subject for the design of parts made of GF-PP. In the literature, several approaches are available for modeling failure; in this paper, several failure criteria are considered, and the predicted results are compared, also with reference to experimental evidence.