Damage identification for irregular-shaped bridge based on fuzzy C-means clustering improved by particle swarm optimization algorithm
Damage identification for irregular-shaped bridge based on fuzzy C-means clustering improved by particle swarm optimization algorithm
复制标题
基于粒子群优化算法改进模糊C均值聚类的不规则形状桥梁损伤识别
DOI：
10.21595/jve.2016.16817
复制
发表时间：
2016
影响因子：
1
通讯作者：
Jiao Yubo
中科院分区：
文献类型：
--
作者：
Liu Hanbing;Wang Xianqiang;Jiao Yubo
异形桥是城市立交桥的重要组成部分，由于严重的超载和材料劣化，极易发生破坏。结构损伤检测是预防桥梁失效、保障城市交通安全运行的必要手段。在基于振动的损伤检测方法中，由于传感器数量有限，很难测量出结构的振型，而可以方便、准确地获得结构的固有频率。提出了一种利用损伤区域的振型频率变化率和均匀载荷面曲率差的比值进行损伤识别的两阶段方案。采用粒子群算法改进的模糊C均值算法(FCM-PSO)进行损伤定位和损伤程度预测。首先，基于FCM-PSO分析，将训练样本的振型频率变化率分成若干类。并构造了损伤位置的聚类中心。通过计算识别指标向量与损伤位置聚类中心之间的模糊隶属度来识别损伤位置。在获得损伤位置后，建立损伤区域的ULSCD值，根据损伤等级中的隶属度来评估损伤严重程度。对典型异形桥梁的损伤识别结果表明，两阶段损伤识别方法对结构损伤的发生、位置和程度的识别是有效和准确的。
Irregular-shaped bridge is an important component of urban overpass and is prone to damage due to severe overloading and material deterioration. Structural damage detection is necessary to prevent bridge failure and guarantee the safe operation of urban traffic. For vibration-based damage detection methods, mode shape of full-scale structure is difficult to be measured with the limited number of sensors, while modal frequency can be obtained accurately and conveniently. This paper aims to propose a two-stage scheme for damage identification using the ratios of modal frequency changes and uniform load surface curvature difference (ULSCD) in damage region. FCM algorithm improved by PSO algorithm (FCM-PSO) is employed to locate damage and predict the damage extent. Firstly, the ratios of modal frequency changes from training cases are classified into several clusters based on FCM-PSO analysis. And the cluster centers for damage locations are constructed. Damage location can be identified by calculating the fuzzy memberships between identification indicator vector and cluster centers of damage locations. After obtaining the damage location, ULSCD values in damage region are established to assess damage severity based on the memberships in damage grades. Damage identification results for typical irregular-shaped bridge demonstrate that the two-stage damage identification method is efficient and accurate to identify the occurrence, location and extent of structural damage