基于静载试验的PPC斜拉桥有限元模型修正分析

Finite element model updating of PPC cable stayed bridge based on the static load experiment

基于有限元模型建立模态柔度矩阵进行模态振型和固有频率与边界刚度系数间的灵敏度分析,推导柔度矩阵与边界支撑刚度及斜拉桥索刚度之间的灵敏度系数矩阵,建立实测挠度和理论挠度的差值与刚度修正值之间的关系表达式,并以实际斜拉桥的缩尺结构为试验模型进行静载试验,以挠度残差为目标函数对有限元模型进行修正,验证本模型的可行性。研究结果表明:模型经过修正后,挠度理论值和试验值基本一致,可为类似工程研究和应用提供借鉴。

The modal flexibility matrix was established based on the finite element model.The sensitivity analysis,between the modal parameters,natural frequency and the boundary stiffness coefficients,was performed.The sensitivity coefficient matrix for the relationship between the flexibility matrix and the stiffness of the boundary support and the cable of the cable-stayed bridge was then derived.According to the difference value between the measured deflection and the theoretical deflection,the relationship expression between the difference value and the stiffness correction value was established.Subsequently,the scaled structure of the real cable-stayed bridge was used as a verification model.The deflection residual was set as the objective function to modify the finite element model,verifying the feasibility of this model.The calculation results show that the theoretical value of deflection is basically the same as the experimental value after the revising of the model.It can provide reference for the research and application of similar engineering.