Response covariance-based sensor placement for structural damage detection

Abstract

One important function of a structural health monitoring system is to detect structural damage in a structure. However, this is a very challenging task since the measurement is often incomplete in a civil structure due to a limited number of sensors. This paper presents a response covariance-based sensor placement method for structural damage detection with two objective functions for optimisation. The relationship between the covariance of acceleration responses and the covariance of unit impulse responses of a structure subjected to multiple white noise excitations is first derived. The response covariance-based damage detection method is then presented. Two objective functions based on the response covariance sensitivity and the response independence are, respectively, formulated and finally integrated into a single objective function for optimal sensor placement. Numerical studies are conducted to investigate the feasibility and effectiveness of the proposed method via a three-dimensional frame structure. Numerical results show that the proposed method with the backward sequential sensor placement algorithm is effective for damage detection.

Keywords:

• Sensor placement
• response covariance
• unit impulse response
• sensitivity analysis
• response independence
• damage detection

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Erratum

Acknowledgments

The authors wish to acknowledge the financial supports from the Research Grants Council of the Hong Kong (PolyU 5289/12E) and The Hong Kong Polytechnic University through its collaborative research project with Beijing University of Technology (4-ZZGD). Any opinions and conclusions presented in this paper are entirely those of the authors.