Modeling of low velocity impact damage in injection-molded long fiber composites

In addition to the increase in failure strength, increase in the impact resistance is one of the major reasons for the interest in long-fiber polymer composites for automotive structural applications. The in-house code EMTA-NLA has been adapted to accommodate dynamic impact problems. It combines with the ABAQUS Explicit solver to model impact behavior of long-fiber thermoplastics (LFTs). At the present stage, the model captures the elastic behavior of LFTs in a dynamic formulation that incorporates the Eshelby equivalent inclusion method, the Mori-Tanaka mean-field approach and the fiber orientation averaging technique. The effect of fiber length distribution on the impact behavior of discontinuous fiber composites has been studied using this model. Fiber lengths from the short fiber range to long fiber range were explored with fiber orientation distributions obtained from previous studies. The numerical examples indicate an improvement in the energy absorption capabilities of LFTs over short fiber thermoplastics.