Damage Detection in Beam-Like Structures Using Deflections Obtained by Modal Flexibility Matrices

Abstract:

In bridge structures, damage may induce an additional deflection which may naturally contain essential information about the damage. However, inverse mapping from the damage-induced deflection to the actual damage location and severity is generally complex, particularly for statically indeterminate systems. In this paper, a new load concept, called the positive-bending-inspection-load (PBIL) is proposed to construct a simple inverse mapping from the damage-induced deflection to the actual damage location. A PBIL for an inspection region is defined as a load or a system of load which guarantees bending moment to be positive in the inspection region. From the theoretical investigations, it was proven that the damage-induced chord-wise deflection (DI-CD) has the maximum value with the abrupt change in its slope at the damage location under a PBIL. Hence, a novel damage localization method is proposed based on the DI-CD under a PBIL. Experimental verification study was also carried out on a two-span continuous steel box-girder model with a steel box-girder. It was found that the proposed method clearly identified the damage existence and damage location for small damage cases with narrow cuts at the bottom flange.

• Periodical: Advances in Science and Technology (Volume 56)
• Pages: 483-488
• DOI: https://doi.org/10.4028/www.scientific.net/AST.56.483
• Online since: September 2008
• Authors: Ki Young Koo, Jong Jae Lee, Chung Bang Yun, Jeong Tae Kim
• Keywords: Beam-Like Structure, Deflection-Based Damage Detection, Measurement Noise, Modal Flexibility, Outlier Analysis, Positive Bending Inspection Load

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