Stacked Shell Modeling for Evaluation of Composite Delamination in Full Vehicle Simulations

Accurate prediction of delamination in composite materials is a challenge and often limits the application of lightweight materials in safety relevant components, as it may reduce the available strength significantly. Very detailed modeling (e.g. with solid elements) can be employed to correctly recreate this phenomenon, but this can normally not be simulated in a full vehicle simulation in an acceptable amount of time. Single shell modeling is widely used in full vehicle simulations because of its high runtime performance but cannot support the physical separation of layers. In order to correctly evaluate delamination of composites while retaining a good runtime performance, a new modeling approach in LS-DYNA® was studied in this paper. A stacked shell modeling technique was developed. The new modeling approach was firstly investigated at coupon level with comparison with experimental results for assessing its accuracy and capability of delamination prediction. Furthermore, stacked shell modeling was adopted into components under more complex loading and its performance was evaluated in terms of accuracy and run time compared with conventional modeling. At the end, this modeling technique was studied in full-vehicle simulation. Our stacked shell modeling approach has shown promising results at coupon and component level. At the full-vehicle simulation scale, the new modeling approach has presented robust delamination prediction capability while still retaining high run time performance. The approach presented in this paper can be adopted in full-vehicle crash and also aerospace simulations in order to evaluate composite delamination.