预制节段拼装梁桥车桥耦合振动分析

预制节段拼装结构具有标准化程度高、建设速度快等优势, 被应用在越来越多的桥梁上, 然而其车桥耦合振动研究较少。文章依据 Runge-Kutta 法在 MATLAB 软件中编写考虑随机路面不平整度的 1/4 车辆模型的求解程序来求解车辆模型, 路面不平整度函数采用三角级数正弦波叠加模拟, 桥梁阻尼采用 Rayleigh 阻尼; 采用约束方程法对胶接缝进行模拟, 利用 ANSYS 求解桥梁模型; 再采用全过程迭代法对车桥耦合模型进行求解, 以桥梁各跨跨中竖向振动响应为指标, 研究路面不平整度、车辆速度、桥梁阻尼比以及胶接缝对预制节段拼装梁桥各跨跨中竖向振动响应的影响。结果表明: 预制节段拼装梁桥的车桥耦合振动响应随路面不平整度的增大而增大, 随桥梁阻尼比的增大而减小, 有无接缝的影响较小; 车辆速度对跨中竖向振动的影响会随着车辆位置的变化而改变且不是单调的; 车桥力的频率也有不可忽视的影响, 且不是单调的。

The precast segmental assembly structure has the advantages of high standardization and fast construction speed. It is applied to more and more bridges. However, its vehicle-bridge coupled vibration is rarely studied. According to Runge-Kutta method, the solution program of 1/4 vehicle model considering random pavement roughness was compiled in MATLAB to solve the vehicle model. The sine wave of trigonometric series superposition was used to obtain the pavement roughness function. Bridge damping was simulated with Rayleigh damping. The constraint equation method was used to simulate the epoxy resin joint to solve the bridge model in ANSYS. Then the coupling model was solved with the inter-system iteration method. With the vertical vibration response of each span as the index, the influence of pavement roughness, vehicle speed, bridge damping ratio and epoxy resin joint on the vertical vibration response of each span of precast segmental bridge was studied. The results showed that the vehicle-bridge coupled vibration response increased with the increase of pavement roughness, decreased with the increase of bridge damping ratio, while the presence of epoxy resin joint was of little influence. The effect of vehicle speed on the vertical vibration of each span was not monotonic, but varied with the vehicle position. The frequency of vehicle-bridge force also had a non-negligible effect, and was not monotonic.