Approach for Modelling Thermoplastic Generative Designed Parts

This study presents an approach to characterize thermoplastic generative designed parts and compares the usability of different material models in LS-DYNA. For using 3D printed parts in prototypes it is at first necessary to be able to predict the deformation behaviour of the printed part itself. The deformation behaviour of thermoplastics and especially of thermoplastic generated parts depends on a variety of material properties. In general the parts have a composed anisotropy consisting of the process and material anisotropy. The process anisotropy is reflected to different mechanical properties due to the building directions of the 3D printer. The material anisotropy includes divergent tension and compression behaviour and approximately orthotropic behaviour due to particle reinforcement. The main task therefore is to evaluate current material routines and modeling techniques to ensure the predictability of the parts behaviour with available and implemented material cards. The performed characterization consists standard specimen tests for a non-reinforced and a carbon particle reinforced thermoplastic, which is produced in the selective laser sinter process. The conducted tests are a tensile, a compression and a shear test. The test specimen were built in different construction directions. In addition, component tests were executed in order to evaluate the predictability of the generated material cards in multiaxial stress states.