Verification of Plane Stress Material Model Behaviour in Solid 3D-Structures

Abstract

In the automotive industry, car crash simulations are an important tool to use in the development process. To accurately capture material behaviour, a well-calibrated material failure model must be used. Volvo Cars Corporation is currently using an advanced material failure model called “MF GenYld + CrachFEM” which is calibrated for the use of shell elements. However, in recent years there has been an increasing interest for the use of 3D solid elements.

The main objective of this project is to assess the CrachFEM model to evaluate its suitability for the use of 3D solid elements by comparing LS-DYNA simulations of both shells and solids to physical tests. Additionally, the CrachFEM model is compared to another material damage model called GISSMO. Also, with different feasible alternatives to CrachFEM such as the Cockcroft-Latham and modified Mohr-Coloumb failure criteria. Assessments are made on three levels of analysis, which are ordered in increased complexity. The first level is single element simulations, the second level tests coupon simulations, and the third level is component simulations.

The results of the project indicate that CrachFEM is very limited when it comes to solid elements, and further use of the material damage model GISSMO might be beneficial, since it offers much more flexibility and options for calibration to capture experimental data more accurately with solid elements.