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.

摘要

在汽车发生侧面碰撞事故时，汽车门槛对维护乘客的生存空间起着重要作用，因此门槛的耐撞性设计可以有效提高汽车的碰撞安全性。受泡沫填充双管优异的承载和吸能能力的启发，提出了一种由原始门槛、泡沫铝和方管组成的夹层门槛。通过有限元模拟研究了夹层门槛的三点弯曲行为以及管材形状对夹层门槛抗弯性能的影响。结果表明，随着方管外长的增加，夹层门槛的抗弯能力先增大后减小。夹层门槛的平均抗弯能力可提高185%，而填充量仅为原门槛的17.2%。此外，在拐角处引入泡沫填充方案，实现轻量化设计，既保证了填充门槛抗弯能力的提高，又大大降低了填充结构的质量。还进行了三点弯曲实验以测试泡沫填充角的阈值。最后，通过采用构件建模方法的车辆侧杆碰撞仿真，验证了夹层和泡沫填角阈值能够有效提高汽车的耐撞性。引入边角泡沫填充方案，实现轻量化设计，既保证了填充门槛抗弯能力的提高，又大大降低了填充结构的质量。还进行了三点弯曲实验以测试泡沫填充角的阈值。最后，通过采用构件建模方法的车辆侧杆碰撞仿真，验证了夹层和泡沫填角阈值能够有效提高汽车的耐撞性。引入边角泡沫填充方案，实现轻量化设计，既保证了填充门槛抗弯能力的提高，又大大降低了填充结构的质量。还进行了三点弯曲实验以测试泡沫填充角的阈值。最后，通过采用构件建模方法的车辆侧杆碰撞仿真，验证了夹层和泡沫填角阈值能够有效提高汽车的耐撞性。