公路波形梁护栏改造临界高度仿真研究

Simulation Research on Critical Protection Height of Highway Guardrail Reconstruction

针对公路加铺罩面导致路侧波形梁护栏防护高度下降引起的波形梁护栏防护等级不足问题,运用HyperMesh和LS-DYNA联合仿真方法,基于加铺罩面导致的护栏高度降低值建立了5种高度的二(B)级波形梁护栏有限元模型,开展了皮卡车、货车分别碰撞护栏的仿真试验。选择车辆侧翻、车辆重心加速度、车辆驶出角度、护栏最大动态变形量4个指标对护栏的防撞性能进行评价。研究结果表明:护栏高度与车辆重心加速度、驶出角度呈负相关关系,与最大动态变形量呈正相关关系。当护栏高度低于标准护栏高度150 mm时,皮卡车与货车均会发生侧翻。因此,车辆重心加速度、驶出角度、车辆侧翻指标能够用于护栏加高的判断指标。综合各指标分析结果,当二(B)级波形梁护栏高度低于标准时,需要进行加高设计。

The insufficient protection level of the W-beam guardrail caused by the reduced protection height of the roadside W-beam guardrail is due to overlay.Based on the reduced height value of guardrail due to overlay,this paper uses HyperMesh and LS-DYNA joint simulation method to establish 5 kinds of height finite element models of B class W-beam guardrails and carries out the collision simulation tests of both vehicle and truck.The anti-collision performance of the guardrail was evaluated by 4 selected indicators:vehicle rollover,vehicle center of gravity acceleration,vehicle exit angle,and maximum dynamic deformation of the guardrail.The research results show that the height of the guardrail is negatively correlated with the acceleration and exit angle of the vehicle s center of gravity,and is positively correlated with the maximum dynamic deformation.When the guardrail height is less than 150 mm of the standard guardrail height,the vehicle and the truck will roll over.Therefore,the vehicle center of gravity acceleration,the exit angle,and the vehicle rollover index can be used as the judgment indicators for the guardrail heightening.Based on the analysis results of all the index,when the height of the B-class W-beam guardrail is lower than the standard,the heightening design is required.