Crashworthiness optimization of cylindrical negative Poisson's ratio structures with inner liner tubes

A novel structure with enhanced energy absorption is proposed by introducing thin-walled tube as the inner liner tube of the cylindrical structures with negative Poisson's ratio (C-NPR). The energy absorption performances of C-NPR structure with inner tube (C-NPR-IT) are compared to other configurations like the single NPR structure, single thin-walled tube, and C-NPR structure with outer tube (C-NPR-OT) to show its superiority. It is found that the interaction between the NPR structure and inner tube in C-NPR-IT can be enhanced. Then, the parametric analysis of the geometric parameters on the crashworthiness performance of C-NPR-IT structures are performed with finite element method. To achieve the best configuration, the surrogate modeling technique and the multi-objective particle swarm optimization (MOPSO) algorithm are employed to optimize the C-NPR-IT structures. The results show that the optimized structure improves the specific energy absorption (SEA) from 3.97 to 10.26 kJ/kg by almost 2.5x by controlling peak crushing force (PCF) less than 80 kN. Therefore, the C-NPR-IT structure has an application prospective in the energy absorber.

Automated summary

A novel structure is proposed to enhance energy absorption by introducing thin-walled tube as the inner liner tube in cylindrical structures with negative Poisson's ratio (C-NPR). Parametric analysis and optimization techniques improve crashworthiness performance, increasing specific energy absorption to 10.26 kJ/kg.