Characterization and Material Card Generation for Thermoplastics

Modelling polymer materials for crashworthiness applications is still an ongoing and challenging topic. Besides the constitutive model the spatial discretization plays a significant role in setting up predictive models in impact scenarios where damage and fracture are dominating the part deformation. Therefore, the limits of the chosen spatial discretization shall always be kept in mind. However, the present contribution is focused on recent enhancements of constitutive models for polymeric materials. This topic is as well ongoing for many years and has been tackled almost 2 decades ago by the development of MAT_SAMP-1 (#187) in LS-DYNA®. Many years of continuous improvement lead to a versatile and usable as well as predictive model. Unfortunately for the cost of slow execution speed if the parameter set or the various curve definitions were not chosen wisely. Therefore, a simplified model with the aim to have a more competitive model available when it comes to computing speed was developed. The so called SAMP_LIGHT (#187L) model comes with a complete redesign for speed but also with a number of limitations (due to the speed argument) and still seems to be versatile enough for everyday simulations. The present contribution recalls the features of SAMP-1 and discusses some of the issues that may lead to exaggerated execution time. Then the reduced model is described and a viable approach to convert available SAMP-1 constitutive data towards SAMP_LIGHT is presented. Clearly the limited model may not be as predictive as the fully flavored one – but the drawbacks may not be severe enough to not give it a try.