基于车桥耦合振动特性,应用达朗伯(D’Alembert)原理和欧拉-柏努利梁(Euler—Bernoulli)假设,建立了跳车试验中动力时程响应的理论计算模型。由于跳车试验对桥梁结构施加的是冲击脉冲激励,利用极限原理和动量守恒理论,推导了确定求解理论计算模型所需初始条件的基本方程,利用龙格-库塔方法对理论计算模型进行求解。并基于动力时程响应,给出了极限跳车高度的判定方法。最后以某钢筋混凝土梁桥为例,确定了桥梁动态检测极限跳车高度,并计算了桥梁的动力响应。结果表明:所述方法是正确和有效的。
Based on the characteristic of vehicle-bridge coupling vibration, the theoretical calculation model of limit bump height in vehicle bump test was established using D'Alembert principle and the hypothesis of Euler-Bernoulli beam. As bump test applies an impact pulse excitation to bridge structure, the fundamental equations to determine initial conditions of the calculation model were derived using the limit theorem and momentum conservation law. The theoretical calculation model was solved by using Runge-Kutter method. The judgment method of limit height in bump test was given based on the dynamic response of bridge. Finally a reinforced concrete beam bridge was taken as an example, and the dynamic response of this bridge was calculated to determine the limit bump height in bridge dynamic test of this bridge. The correctness and effectiveness of this method was validated.