多参数车桥碰撞动力响应分析
Dynamic Response Analysis of Vehicle-Pier Collision with Multi Parameters

桥梁纵坡、碰撞力水平偏角、碰撞力水平偏心是车桥碰撞的主要几何参数，研究不同车速条件下，上述参数对车桥碰撞动力响应的影响。基于车辆简化模型，采用ANSYS和LS-DYNA软件，建立车桥碰撞三维仿真动力有限元模型，以方形墩为例，分析车桥碰撞几何参数在设计时速为40 Km/h、60 Km/h、80 Km/h时对桥墩的顺桥向撞击力的影响。分析表明，顺桥向撞击力峰值随碰撞速度的增加而增加。就同一碰撞速度而言，随着桥梁纵坡的增大，顺桥向碰撞力最大值呈现下降趋势。随着碰撞力水平偏角增加，顺桥向碰撞力峰值呈现下降趋势。当碰撞力水平偏心距小于0.8 m时，顺桥向碰撞力峰值随着碰撞力水平偏心的增加呈增大趋势。当撞击偏心距为0.8 m时，顺桥向碰撞力峰值达到最大值。当偏心距大于0.8 m时，顺桥向碰撞力峰值随偏心距增大呈减小趋势。该研究指出了不同车速条件下车桥碰撞几何参数与顺桥向碰撞力峰值的变化关系规律，可为桥梁防撞决策和防撞设计提供理论依据。
Longitudinal slope along the bridge, horizontal impact angle and horizontal eccentricity are the main geometric parameters of vehicle-pier collision. The influence of these parameters on vehicle-pier collision dynamic response under different vehicle speeds is studied. Based on the simplified vehicle model, a three-dimensional dynamic finite element model for vehicle-pier collision simulation is established by using ANSYS and LS-DYNA software. Taking a square pier as an example, the effects of the geometric parameters on the impact force along the bridge when the speed is 40 Km/h, 60 Km/h, 80 Km/h are analyzed. The results show that the maximum impact force along the bridge increases with the increase of impact speed. At the same speed, as the slope increases, the maximum impact force along the bridge shows a decreasing trend. With the increase of horizontal impact angle, the maximum impact force along the bridge shows a decreasing trend. When the horizontal eccentricity is less than 0.8 m, the maximum of the impact force along the bridge increases with the increase of the horizontal eccentricity. When the horizontal eccentricity is 0.8 m, the peak value of impact force along the bridge reaches the maximum value. When the horizontal eccentricity is greater than 0.8 m, the peak value of impact force along the bridge decreases with the increase of horizontal eccentricity. The research points out the trend of the relationship between the geometry parameters and the peak value of impact force, which can provide a theoretical basis for bridge collision prevention decision and design.