Simulation of Mechanical Properties of Injection-Molded Thermoplastic Foam Structures

This article presents an approach regarding the interlinking of simulation programs to determine mechanical properties of foamed polymers. The software Moldex3D is used to simulate the heterogeneous foam structure, which serves as a database for material modeling. This material modeling is performed with the software Digimat and evaluated using various modeling approaches. The material models are characterized on one side by a homogeneous structure and on the other by the simulated heterogeneous foam structure. In addition, different failure indicators are used and evaluated, which were originally developed for fiber-reinforced materials. The simulation of the tensile test is carried out with the software Marc-Mentat. Herein, local stresses and strains are calculated, which reach a maximum value due to the influence of the failure indicators. The results are used to show the extent to which the integration of the heterogeneous foam structure proves to be beneficial. It is additionally demonstrated that the applied failure indicators cannot be used for the prediction of maximum stress and strain simultaneously. Thus, for the time of this study, it is formulated to include both indicators to calculate the maximum stress and strain or to evaluate alternative approaches regarding failure prognosis.