Delamination Modeling of Composites for Improved Crash Analysis

Abstract

Modeling of crashworthy composite structures is limited by the inability of current generations of finite element crash codes to effectively model certain critical failure modes, such as delamination. Previous efforts to model delamination and debonding failure modes using crash codes have typically relied on ad hoc failure criteria and quasistatic fracture data. Improvements to these modeling procedures can be made by using an approach based on fracture mechanics. Finite element predictions of delamination growth using the virtual crack closure technique are implemented using the finite element crash code MSC/DYTRAN and compared with other methods of modeling delamination in finite element crash analyses. Computational results for composite double cantilever beam specimens are compared with experimental results from the literature. This investigation demonstrates the potential for improving the crash modeling of composites through improved delamination modeling. Further developments to this approach may result in improved analytical tools that can be used to model delamination using current generation crash codes.