Removal of masking effect for damage detection of structures

Wah, William Soo Lon; Owen, John S.; Chen, Yung-Tsang; Elamin, Ahmed; Roberts, Gethin Wyn

Abstract

Damage detection of civil engineering structures relies heavily on the use of outlier analysis/novelty detection analysis. Generally, data captured from a structure in its normal environmental condition are used to create a model and compute control limits to represent the normal range of variations of damage sensitive features of the structure. However, the training database used usually includes outlier measurements, which may introduce masking effect. These outlier measurements can affect the mean and standard deviation/covariance matrix of the training database, and hence, affect the model and the control limits. As a result, small damage may not be detected. Therefore, this paper proposes an approach of selecting a `clean' training database for the construction of the baseline of the undamaged structure so as to detect damage at an earlier stage. The approach makes use of Principal Component Analysis and Median Absolute Deviation to identify outlier measurements. This approach can be applied before the application of damage detection methods to allow damage to be detected at an earlier stage. The proposed approach is applied to a numerical beam model and the Z24 Bridge, in Switzerland. The results obtained demonstrate that damage can be detected at an earlier stage using the approach proposed in this paper. The proposed method also allows the determination of the model (e.g. linear or nonlinear) to be used for damage detection.

Citation

Wah, W. S. L., Owen, J. S., Chen, Y., Elamin, A., & Roberts, G. W. (2019). Removal of masking effect for damage detection of structures. Engineering Structures, 183, 646-661. https://doi.org/10.1016/j.engstruct.2019.01.005

• Journal Article Type: Article
• Acceptance Date: Jan 1, 2019
• Online Publication Date: Jan 18, 2019
• Publication Date: Mar 15, 2019
• Deposit Date: Jan 7, 2019
• Publicly Available Date: Jan 19, 2020
• Journal: Engineering Structures
• Print ISSN: 0141-0296
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 183
• Pages: 646-661
• DOI: https://doi.org/10.1016/j.engstruct.2019.01.005
• Keywords: Civil and Structural Engineering
• Public URL: https://nottingham-repository.worktribe.com/output/1447334
• Publisher URL: https://www.sciencedirect.com/science/article/pii/S0141029618325070
• Additional Information: This article is maintained by: Elsevier; Article Title: Removal of masking effect for damage detection of structures; Journal Title: Engineering Structures; CrossRef DOI link to publisher maintained version: https://doi.org/10.1016/j.engstruct.2019.01.005; Content Type: article; Copyright: © 2019 Elsevier Ltd. All rights reserved.