基于柔度指标的变截面连续梁桥损伤识别方法  

Damage Identification Method of Variable Cross-section Continuous Beam Bridge Based on Flexibility Curvature Area Difference

作　　者：刘润州 LIU Runzhou(School of Civil Engineering,Anhui Jianzhu University,Hefei 230601,China)

机构地区：[1]安徽建筑大学土木工程学院,安徽合肥230601

出　　处：《佳木斯大学学报（自然科学版）》2023年第4期113-116,166,共5页Journal of Jiamusi University：Natural Science Edition

基　　金：建筑健康监测与灾害预防国家与地方联合工程实验室开放课题(GG22KF002)。

摘　　要：针对模态柔度及其衍生指标具有对结构损伤高灵敏性的特点,为研究基于柔度类指标的损伤识别方法在变截面连续梁桥上的适用性,提出一种基于柔度曲率面积差的桥梁损伤识别新指标。首先利用结构振型和固有频率构建柔度矩阵,其次对柔度矩阵进行行列两次差分得到柔度曲率矩阵,然后提取损伤前后柔度曲率矩阵主对角元素构建柔度曲率面积差(Flexibility curvature area difference,FCAD)指标,以三跨变截面连续梁桥有限元模型为研究对象,对不同损伤工况进行模拟分析以验证方法的可行性和有效性,通过引入不同强度噪声来验证该方法的抗噪性。研究结果表明:柔度曲率面积差方法可有效对三跨变截面连续梁桥的损伤进行定位,且所提方法具有较好的噪声鲁棒性。In view of the high sensitivity of modal flexibility and its derived indicators to structural damage,a new indicator for bridge damage identification based on flexibility curvature area difference is proposed to study the applicability of damage identification methods based on flexibility indicators on variable cross-section continuous beam bridges.First,the flexibility matrix is constructed by using the structural vibration mode and natural frequency,and then the flexibility curvature matrix is obtained by two times of row and column difference.Then,the main diagonal elements of the flexibility curvature matrix before and after damage are extracted to construct the flexibility curvature area difference(FCAD)index.The finite element model of three-span continuous beam bridge with variable cross-section is taken as the research object.The feasibility and effectiveness of the method are verified by simulating and analyzing different damage conditions,and the noise resistance of the method is verified by introducing different intensity noise.The results show that the flexibility curvature area difference method can effectively locate the damage of three-span continuous beam bridge with variable cross-section,and the proposed method has good noise robustness.

关 键 词：变截面连续梁桥 损伤识别 柔度矩阵 柔度曲率面积差 数值模拟 

分 类 号：U448.21[建筑科学—桥梁与隧道工程]