桥梁复合材料防车撞结构的耐撞性影响因素分析

摘要

设计了一种蜂窝型复合材料桥梁防车撞结构,以钢板和复合材料管壁厚度为设计变量,通过有限元方法计算,得到不同工况下车辆碰撞防车撞结构时的碰撞力曲线和结构总吸能.针对防车撞结构因存在多种材料而不便比较单位质量下能量吸收的情况,提出了比造价吸能(SEAc)的耐撞性评价指标.分析了防车撞结构钢板厚度及复合材料管壁厚度对碰撞力和比吸能的影响,并与车辆直接撞击桥墩的计算结果进行了对比.结果表明,从耐撞性的角度考虑,设计的复合材料防车撞结构中的钢板厚度及管壁厚度存在着最优厚度组合,采用该厚度组合时防车撞结构能在较低造价下提供良好的吸能效果,且桥墩所受的碰撞力满足我国规范的相关要求.%A honeycomb steel-composite protection structure is designed in this paper, and the thicknesses of steel and composite are considered as the design variables.By finite element method, collision force curve and total energy absorption are acquired in car-structure collision.Moreover, SEAc is proposed as the crashworthiness assessment indicator since it is difficult to compare the energy absorption per unit mass for the structure with several kinds of materials.The influence of the structure thickness on crashworthiness is analyzed and compared with the car-bridge collision condition.The result indicates that an optimal combination of steel thickness and composite thickness exists from the perspective of crashworthiness.Based on this optimal combination, the honeycomb steel-composite protection structure can provide good energy absorption effect with lower costs and the collision forces satisfy the national standards of China.