基于下承式钢管混凝土系杆拱桥冲击系数的分析

Impact Coefficient of Supported Steel Pipe Concrete Tied Arch Bridge

采用有限元软件ANSYS建立了该桥的立体模型和双轴汽车模型,使用相关约束方程使轮子和系杆拱桥桥梁接触点位移相同,运用APDL语言编写车-桥耦合的振动计算命令流,采用瞬态动力学进行求解。分析了桥面不平顺、汽车行驶速度、汽车数量以及汽车之间间距对钢管混凝土系杆拱桥的动力响应和冲击系数的影响。结果表明:桥面粗糙程度、行车快慢、行车数目以及汽车之间的距离均会对大桥的冲击系数产生影响;桥梁最大动位移随车速的增加变化很小;随着车速的增加钢管混凝土系杆拱桥与简支梁桥冲击系数变化趋势相同。

The three-dimensional bridge model and two-axis vehicle model were established in the present paper by the finite element software ANSYS. With the relative constraint equations guaranteeing that the wheel displacement is consistent with the tied arch bridge point, the vehicle-bridge coupling vibration command flow was written by the ANSYS Parametric Design Language and solved by transient dynamics. Effects of the irregularities of bridge deck, the vehicle speed, the vehicle number and the distances between vehicles on the dynamic response and impact coefficient of concrete-filled steel tube arch bridge were also analyzed. The results showed that the irregularities of the bridge deck, the vehicle speed, the vehicle number and the distances between vehicles influenced the impact coefficient of the bridge. With increasing vehicle speed, the maximum dynamic displacement of the bridge varied little, and variation tendencies of the impact coefficients for the concrete-filled steel tube arch bridge and the simply supported beam bridge were the same.