垂向强冲击载荷下车辆缓冲座椅的安全带系统防护性能分析及优化

Analysis and optimization of protection provided by vehicle anti-shock seat safety belt systems under vertical intensive shock loads

针对特种车辆受到垂向强冲击时缓冲座椅的安全带系统防护性能进行研究,建立了地板-座椅-乘员系统的有限元模型,对驾驶室地板结构施加冲击位移输入,应用数值仿真方法比较分析了缓冲座椅分别匹配两点式、三点式、四点式和六点式安全带时对乘员的约束效能。在垂向强冲击载荷下,具有六点式安全带的缓冲座椅可有效地减小腰椎轴向压力峰值,同时降低乘员与车身结构发生冲击碰撞的可能性。进一步对六点式安全带的预紧特性和限力特性参数进行了多设计方案分析和优化,具有匹配优化后的预紧特性和限力特性的六点式安全带可使乘员的腰椎轴向压力峰值比优化前降低10.7%,比三点式安全带显著地提高了缓冲座椅抗垂向强冲击的安全性。

A finite element model of a cab floor-seat occupant sub system was developed for special purpose vehicles to study the vertical shock protection provided by anti-shock seat systems with safety belts. The model inputs are a set of shock displacement-time histories experienced by the vehicle cab floor. Numerical simulations are used in a comparative study of the protection provided by safety belts anchored at two, three, four and six points during vertical intensive shock loads. The safety belts with six anchor points reduce the axial compression force on the lumbar spine and effectively prevent secondary impact between the lower limbs and the vehicle structures. The influences of the pretension and the forceqimit characteristics of the safety belts with six anchor points on occupant injuries are analyzed to optimize the pretension and force-limit parameters. The results show that the optimal safety belts with six anchor points reduce the peak axial compression force on the lumbar spine by 10. 7% compared with the initial design. The vertical shock protection provided by the anti shock seat system is effectively improved compared to safety belts with three anchor points.