装配式防撞护栏方案与车辆碰撞仿真性能分析

Performance Analysis of Assembled Crash Barrier Scheme and Vehicle Crash Simulation

本文以武汉市某大道高架桥SA级装配式混凝土防撞护栏为工程背景,提出了一种新型C40混凝土装配式防撞护栏竖向连接设计方案,即预埋H型钢焊接与浆锚连接相结合,护栏节段之间通过钢筋连接.基于LS-DYNA分别建立了1.5 t小型客车、14 t大型客车和25 t大型货车20°斜向撞击装配式护栏的有限元模型.通过阻挡性能、缓冲性能和导向性能等评价指标,评价装配式防撞护栏的安全性能.结果表明:在车辆碰撞作用下,护栏的竖向连接与纵向连接均未失效,护栏具备良好的阻挡性能.碰撞过程中,纵向加速度分量峰值和横加速度分量峰值均低于200 m/s 2,满足标准中加速度评价指标,护栏具备良好的缓冲性能.碰撞结束后,小客车驶出角度为7.8°,大型客车与大型货车驶离护栏轨迹几乎平行与护栏,满足规范要求,护栏具备良好的导向性能.

Based on the engineering background of SA-class assembled concrete crash barrier of a viaduct in Wuhan,a new vertical connection design scheme of C40 assembled concrete crash barrier was proposed,that is,the embedded H-beam welding was combined with the mortar anchor connection,and the guardrail segments were connected by steel bars.Based on LS-DYNA,the finite element models of 1.5t minibus,14t bus and 25t truck impacting assembled guardrail at an oblique angle of 20°were established respectively.The safety performance of assembled anti-collision guardrail was evaluated through the evaluation indexes such as blocking performance,buffering performance and guiding performance.The results show that the vertical connection and longitudinal connection of the guardrail have not failed under the action of vehicle collision,and the guardrail has good blocking performance.During the collision,the peak values of longitudinal acceleration component and transverse acceleration component are both below 200 m/s 2,which meet the acceleration evaluation index in the standard,and the guardrail has good cushioning performance.After the collision,the exit angle of the passenger car is 7.8°,and the trajectories of the large passenger car and the large truck leaving the guardrail are almost parallel to the guardrail,which meets the requirements of the code and the guardrail has good guiding performance.