失控车辆撞击下避险车道末端挡墙的动力响应与损伤特征分析

Analysis of Dynamic Response and Damage Characteristics of End Retaining Wall of Truck Escape Ramp under the Impact of Runway Vehicles

研究失控车辆撞击下避险车道末端挡墙的动力响应与损伤特征可以为避险车道末端挡墙的应用和完善提供理论依据。首先基于LS-DYNA软件建立了车辆-钢筋混凝土挡墙有限元模型,并且通过已有的落锤冲击钢筋混凝土梁试验的结果,对建立的有限元模型进行验证。然后采用正交试验方法对钢筋混凝土挡墙的参数进行了设计。最后进行车辆撞击钢筋混凝土挡墙的非线性有限元仿真,研究车辆的速度、撞击位置、撞击角度以及车辆前保险杠的刚度对钢筋混凝土挡墙的动力响应和损伤特征的影响。结果表明:车辆的速度、撞击角度、保险杠的刚度对于挡墙的动力学响应以及损伤程度均有显著影响,随着车速、撞击角度和保险杠刚度的增加,挡墙的损伤逐渐加剧;挡墙的损伤区域主要分为撞击区域和墙角区域,其中撞击区域的损伤较为严重,破坏形式为冲剪破坏,墙角区域的损伤较轻,破坏形式为剪切破坏。

Studying the dynamic response and damage characteristics of the end retaining wall of truck escape ramp under the impact of an runway vehicle can provide a theoretical basis for the application and improvement of the end retaining wall of truck escape ramp.First,a vehicle-reinforced concrete retaining wall finite element model was established based on the LS-DYNA software,and the established finite element model was verified through the results of the existing drop hammer impact test of reinforced concrete beams.Then the orthogonal test method was used to design the parameters of the reinforced concrete retaining wall.Finally,a nonlinear finite element simulation of vehicle impacting on reinforced concrete retaining wall was carried out to study the influence of the vehicle s speed,impact position,impact angle and the stiffness of the front bumper of the vehicle on the dynamic response and damage characteristics of the reinforced concrete retaining wall.The results show these as follows.Vehicle speed,impact angle,and bumper stiffness have significant effects on the dynamic response of the retaining wall and the degree of damage.With the increase of vehicle speed,impact angle and bumper stiffness,the damage of the retaining wall gradually intensifies.The damage area of the wall is mainly divided into the impact area and the corner area.The damage in the impact area is more serious,and the damage is in the form of punching and shearing.The damage in the corner area is relatively light,and the damage is in the form of shearing.