基于混凝土损伤塑性模型的弯曲损伤RC/PC桥梁动力学特性研究  

Study on Dynamic Characteristics of Bending Damaged RC/PC Bridges Based on Concrete Damage Plasticity Models

作　　者：陈志为[1] 施宇 张尧 CHEN Zhiwei;SHI Yu;ZHANG Yao(School of Architecture and Civil Engineering,Xiamen University,Xiamen 361005,China)

机构地区：[1]厦门大学建筑与土木工程学院,福建厦门361005

出　　处：《湖南大学学报（自然科学版）》2024年第7期50-61,共12页Journal of Hunan University:Natural Sciences

基　　金：国家自然科学基金资助项目(52278319)。

摘　　要：基于混凝土损伤塑性模型,通过数值模拟研究了带有弯曲损伤的RC/PC桥梁动力学特性的退化情况.首先,提出了适用于RC/PC桥梁非线性振动分析的数值模型构建方法.其次,通过RC简支梁受弯破坏试验,将试验结果与数值模拟结果进行比较,验证了数值模型的准确性.最后,基于厦门快速公交系统中某一联三跨PC连续梁桥建立了三维有限元模型,研究其在不同弯曲损伤程度下前三阶频率和振型的变化情况.结果表明,带有弯曲损伤的RC/PC桥梁的动力学特性会随着损伤程度的增加而呈现不同程度的改变.带有混凝土裂缝的桥梁的微幅振动仍然是线性的,然而随着振幅的增大频率开始降低,使振动呈现出非线性.此外,当裂缝闭合时,前三阶自振频率与振型变化不明显,难以用于识别弯曲损伤;当裂缝张开时,前三阶自振频率与振型出现明显变化,可作为损伤检测指标来识别损伤.Based on the concrete damage plasticity model,the dynamic characteristics of bending damaged RC/PC bridges are investigated through numerical simulations in this paper.Firstly,a FE model generation framework was proposed to conduct the nonlinear vibration analysis of RC/PC bridges.Then,the constructed FE model was validated by comparison with experimental results from bending failure tests on simply supported RC beams.Finally,a 3D FE model of a 3-span PC continuous girder bridge from the Xiamen Bus Rapid Transit was established to study the changes in frequencies and mode shapes under different bending damage levels.It can be observed from the results that the dynamic characteristics of RC/PC bridges with bending damage change to varying degrees as the damage increases.The small vibration of the damaged bridge with concrete cracks is still linear,but the frequency decreases with the increasing vibration amplitude,indicating the nonlinear vibration.When cracks are closed,the changes in the first three frequencies and mode shapes are not significant,making it hard to identify bending damage in practice.However,when cracks are open,noticeable changes occur in the first three frequencies and mode shapes,which can serve as damage detection indicators for identification purposes.

关 键 词：RC/PC桥梁 混凝土损伤塑性模型 裂缝开合效应 有限元 数值仿真 

分 类 号：U441.3[建筑科学—桥梁与隧道工程]