Finite element modeling of the crushing behavior of thin-walled CFRP tubes under axial compression

A finite element modeling methodology was developed to study the crushing behavior and energy absorption characteristics of graphite/epoxy laminated circular tubes. Laminated tubes were modeled using multiple layers of shell elements with layers being tied together using tiebreak contact. A progressive damage model was used to simulate the failure within each layer while a mesh-independent energy-based failure criterion for the tiebreaks was implemented in the model to effectively simulate the delamination between layers during the crushing process. Simulation results compared very well with the experiments in terms of the load-displacement behavior, specific energy absorption, and surface strain distribution, and provided a good depiction of the failure process.