大跨度连续刚构桥模态分析与损伤评估

On Modal Analysis and Damage Assessment of Large-Span Continuous Rigid Frame Bridge

为探讨桥梁在外力作用下最易发生损伤的位置以及损伤后其模态参数的变化,以攀枝花金沙江铁路大桥为研究对象,用大型有限元软件ANSYS建立连续刚构桥梁的模型,分别研究了不同位置、不同程度的9种损伤工况,对各工况下的力学指标进行计算,并从静力学和动力学两方面进行了相应分析。研究结果表明:桥梁跨中和墩梁结合部位最易发生损伤,损伤将导致刚度下降,挠度变大;在动力特性方面,损伤将引起桥梁模态参数的变化。

To investigate the most injury- prone position and changes in its modal parameters after injury of bridges under loads,taking the Panzhihua- Jinsha River railway bridge as the research object,establishing a model of continuous rigid frame bridge with the finite element software ANSYS,respectively Research the different locations,different levels of nine cases,the mechanical condition of each index is calculated for the corresponding static and dynamic analysis. The results show that： the bridge span and pier beams binding site most prone to injury,damage will lead to decrease stiffness and deflection becomes larger. The bridge modal parameters will change in dynamic characteristics.