Dynamic response of bionic non-convex tubes with proportional distribution of bulkhead

Non-convex tubes that have superior energy absorption potential may expand and deform unstable during impact, limiting energy absorption. The bamboo node can strengthen bamboo by resisting expansion. Therefore, bulkhead proportional distribution of bionic non-convex (BPDBN) tubes, an integrator of them, may present more efficient energy absorption performance. This research proposed to investigate the effect of geometrical parameters on the crashworthiness characteristics of BPDBN tubes. The position of bulkheads was assumed to vary according to the positive proportional function primarily determined by proportional coefficient k. The dynamic response was evaluated by the initial peak force (IPF), specific energy absorption (SEA), and crush force efficiency (CFE). Multi-objective optimization method was utilized to further improve the energy absorption performance. The optimal design lowered the IPF (34.00%), increased the SEA (37.16%) and the CFE (42.95%). This paper emphasizes that optimizing the geometrical parameters and the bulkhead distance proportion can significantly improve the crashworthiness performance of BPDBN tubes.