Crashworthiness of innovative hexagonal honeycomb-like structures subjected to out-of-plane compression

Seeking for innovative structures with higher mechanical performance is a continuous target in railway vehicle crashworthiness design. In the present study, three types of hexagonal reinforced honeycomb-like structures were developed and analyzed subjected to out-of-plane compression, namely triangular honeycomb (TH), double honeycomb (DH) and full inside honeycomb (FH). Theoretical formulas of average force and specific energy absorption (SEA) were constructed based on the energy minimization principle. To validate, corresponding numerical simulations were carried out by explicit finite element method. Good agreement has been observed between them. The results show that all these honeycomb-like structures maintain the same collapsed stages as conventional honeycomb; cell reinforcement can significantly promote the performance, both in the average force and SEA; full inside honeycomb performs better than the general, triangular and double schemes in average force; meanwhile, its SEA is close to that of double scheme; toroidal surface can dissipate higher plastic energy, so more toroidal surfaces should be considered in design of thin-walled structure. These achievements pave a way for designing high-performance cellular energy absorption devices.