Structure design and multi-objective optimization of a novel NPR bumper system

The aim of this paper is to explore a novel bumper system consisting of a negative Poisson's ratio (NPR) beam and a NPR absorber. The NPR beam is designed to improve the frontal crashworthiness of the vehicle, which is composed of a large number of inner hexagonal cellular structures through periodic arrangement. Meanwhile, the NPR absorber, filled in the space between the bumper beam and the skin, is contrived to protect the pedestrian's lower leg in the collision accident. Based on this, an optimization model is constructed and the multi-objective optimization algorithms are used to search the optimal structural parameters. The simulation results show that the comprehensive performance index of the NPR bumper system optimized by electronic-search algorithm (ESA) algorithm has been effectively improved, and it performs excellent performances in both pedestrian protection and vehicle crashworthiness.