移动车辆荷载作用下中低速磁浮大跨度连续梁桥动力响应分析

Dynamic response analysis of low and medium speed maglev long-span continuous beam bridge traversed by moving train load

为研究中低速磁浮大跨度连续梁桥在移动列车荷载作用下的动力响应,采用移动荷载模拟磁悬浮车辆作用,采用振型分解精细积分法建立桥梁动力方程并求解;通过与现场试验结果对比,验证本文模型的准确性和方法的正确性,对比分析不同行车速度、不同桥梁阻尼比等工况下的桥梁动力响应。研究结果表明:桥梁动力系数随列车速度增加而增大,但整体增加幅度不大;在列车以设计运行速度100km/h行驶时,桥梁阻尼比的变化对桥梁响应影响较小;不同工况下桥梁动力系数均低于我国《中低速磁浮交通设计规范》中的限值。

In order to study the dynamic responses of the low and medium speed maglev long-span continuous beam bridge under the action of the moving train load, the action of maglev train was simulated by the moving load. The dynamic equation of bridge was established and was solved by MDPIM (Mode Decomposition Precision Time Integration Method), through comparison with field test, the accuracy of the finite element model and correctness of method were verified. At last, the dynamic response of bridge under different driving speeds and different damping ratios of the bridge were compared and analyzed. The results show that the dynamic coefficient increases as the train speed increase on the whole, but the increase is not modest. When the train is traveling at the design speed of 100 km/h, the change of the damping ratio of the bridge has little impact on the bridge response. And under different conditions the dynamic coefficient values are lower than the limit value in Code for Design of Low and Medium Speed Maglev Transit.