Crashworthiness design of car threshold based on aluminium foam sandwich structure

Abstract

During a side impact accident of an automobile, the automobile threshold plays an important role in maintaining the living space of passengers, and thus the crashworthiness design of thresholds may effectively improve the crash safety of the car. Inspired by the excellent load carrying and energy absorption capacity of foam-filled double tubes, a sandwich threshold which is composed of an original threshold, an aluminium foam and a square tube was proposed. Finite element simulation was carried out to study the three-point bending behaviour of sandwich thresholds and the influence of the tube shape on the bending resistance of sandwich thresholds. The results show that the bending capacity of sandwich thresholds first increases and then decreases with the increase of the outer length of the square tube. The average bending capacity of the sandwich threshold can be increased by 185%, while the filling mass is only 17.2% of the original threshold. Besides, the filling scheme of foam in corners was introduced to realise the lightweight design, which not only ensures the improvement of the bending resistance of the filled threshold but also greatly reduces the mass of the filling structure. The three-point bending experiments were also performed to test the foam corner-filled threshold. Finally, through the vehicle side pole impact simulation using the component modelling method, it is verified that the sandwich and foam corner-filled threshold can effectively improve the crashworthiness of the car.