基于车桥耦合的钢-混结合段刚度平顺性分析

为了研究混合梁桥结合段动力平顺性问题,针对某混合梁独塔斜拉桥,将结合段按刚度等效换算为同一种材料,建立桥梁有限元模型;基于9个自由度的三轴车辆模型,根据规范规定的路面粗糙度谱,用三角级数法模拟了B级粗糙度样本,采用Newmark-β法求解车桥系统运动方程,建立了汽车-桥梁垂向耦合振动仿真模型.在此基础上,编制了车桥耦合振动分析程序,求解了桥梁结合段和车辆的动力响应. 研究结果表明:路面粗糙度下降一个等级,桥梁结合段竖向加速度增加一倍;从动力性能角度分析,钢-混结合段钢格室全填充时的刚度平顺性略优于半填充时的刚度平顺性. 

Stiffness Transition Analysis of a Steel-Concrete Joint Section Based on Vehicle-Bridge Interaction

In order to study the dynamic stiffness transition issue of hybrid girder bridges, a vertical vehicle-bridge coupled vibration model was built for a cable-stayed bridge with single tower. In the coupled vibration model, a finite element model for the bridge was established by converting the joint section to the same material according to the equivalent stiffness law, a tri-axial vehicle model with 9 degrees of freedom (DOFs) was adopted, the sample of class B road roughness was simulated from the roughness spectrum in the national code by the trigonometric series method, and the motion equations of the coupled vehicle-bridge system were solved by Newmark-β method. According to the vehicle-bridge coupled vibration model, the dynamic analysis codes of the vehicle-bridge interaction were programmed to solve the system's dynamic responses under different conditions. The results show that the vertical acceleration of joint section will double if the road roughness decreases a grade; in dynamic behavior, the dynamic transition of the fully filled joint section is slightly smoother than that of the half filled.