|
|
Journal of Zhejiang University SCIENCE A
ISSN 1673-565X(Print), 1862-1775(Online), Monthly
2025 Vol.26 No.11 P.1052-1069
A two-stage framework for automated operational modal identification using OPTICS-KNN-based clustering
Abstract: Modal analysis, which provides modal parameters including frequencies, damping ratios, and mode shapes, is essential for assessing structural safety in structural health monitoring. Automated operational modal analysis (AOMA) offers a promising alternative to traditional methods that depend heavily on human intervention and engineering judgment. However, estimating structural dynamic properties and managing spurious modes remain challenging due to uncertainties in practical application conditions. To address this issue, we propose an automated modal identification approach comprising three key aspects: (1) identification of modal parameters using covariance-driven stochastic subspace identification; (2) automated interpretation of the stabilization diagram; (3) an improved self-adaptive algorithm for grouping physical modes based on ordering points to identify the clustering structure (OPTICS) combined with k-nearest neighbors (KNN). The proposed approach can play a crucial role in enabling real-time structural health monitoring without human intervention. A simulated 10-story shear frame was used to verify the methodology. Identification results from a cable-stayed bridge demonstrate the practicality of the proposed method for conducting AOMA in engineering practice. The proposed approach can automatically identify modal parameters with high accuracy, making it suitable for a real-time structural health monitoring framework.
Key words: Structural health monitoring; Covariance-driven stochastic subspace identification; Automated operational modal analysis (AOMA); Ordering points to identify the clustering structure (OPTICS); k-nearest neighbors (KNN)
机构:1浙江大学,建筑工程学院,中国杭州,310058;2浙江交工集团股份有限公司,中国杭州,310051;3苏州科技大学,土木工程学院,中国苏州,215011;4浙江大学长三角智慧绿洲研究中心,未来城市实验室,中国嘉兴,314102;5杭州市交通规划设计研究院有限公司,中国杭州,310030
目的:自动化工作模态分析(AOMA)能够有效替代依赖人工干预和工程经验判断的传统模态参数识别方法。本研究提出一种融合协方差驱动随机子空间识别、稳定图自动判读以及密度聚类算法(OPTICS)自适应聚类策略的自动化模态识别框架,有效解决了传统模态参数识别方法的局限性。通过十层剪切框架数值模型和斜拉桥实测数据验证,该方法实现了高精度模态参数自动识别,具备应用于复杂工程结构实时监测的潜力。
创新点:1.采用两种广泛应用的模态验证准则对稳定图进行预处理,以消除部分虚假模态并提高聚类阶段的计算效率;2.通过k近邻算法(KNN)确定最优聚类数量,并基于OPTICS算法实现自动化真实模态聚类。
方法:1.采用协方差驱动随机子空间识别实现结构模态参数提取;2.基于软硬准则开展稳定图的自动化初筛;3.结合OPTICS算法与k-近邻算法实现自适应物理模态聚类。
结论:1.根据十层框架结构与桃夭门大桥的模态参数识别结果,结构的各阶模态频率与阻尼比均保持较小的波动范围,这表明该方法能有效剔除虚假模态并准确识别真实模态。2.该方法对密集模态具有良好辨识能力,在无需预先设定聚类数量或设定聚类阈值的情况下,成功实现此类模态的精准识别。3.通过对桃夭门大桥的监测数据进行分析,进一步验证了该方法在工程实践中的实用性。
关键词组:
References:
Open peer comments: Debate/Discuss/Question/Opinion
<1>
DOI:
10.1631/jzus.A2400538
CLC number:
Download Full Text:
Downloaded:
1225
Download summary:
<Click Here>Downloaded:
6Clicked:
1308
Cited:
0
On-line Access:
2025-11-24
Received:
2024-11-18
Revision Accepted:
2025-02-06
Crosschecked:
2025-11-25