Damage Identification of Shear Connectors with Wavelet Packet Energy: Laboratory Test Study
Publication: Journal of Structural Engineering
Volume 134, Issue 5
Abstract
Shear connectors are widely used to link the slab and girders together in slab-on-girder structures. Assessment of the integrity of shear connectors is an important issue in the maintenance and health monitoring of such structures. In this study, a 1:3 scaled bridge model was constructed with removable anchors linking the slab and girders as shear connectors. Each anchor consisted of a threaded bar penetrating through the soffit of a girder and anchored in the slab by an embedded nut cap with welded steel bar. Different damage scenarios were simulated by removing some of these connectors. A signal-based damage detection method in which the damage feature is characterized by the wavelet packet energy changes was applied to the damage identification of the shear connectors. Using measurements of hammer impact responses, the locations of the loosening of the shear connectors were effectively detected. This paper demonstrates that the wavelet packet-based energy index is a sensitive local damage indicator. The results also show that comparison of the relative vibration between the slab and the girders is a more effective technique for evaluating the shear connector damage than comparison of the vibration of the slab before and after shear connector damage. This finding is particularly interesting because data from the intact (undamaged) bridge is not required. The suitability and efficiency of the approach is expected to be applied in situ to assess the integrity of shear connectors in existing structures.
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Acknowledgments
The writers would like to acknowledge financial support from Australian Research Council (ARC) and Main Roads Western Australia (MRWA) through ARC Linkage Project No. LP0453783. Help from the UWA honors year students Mark Watkins, Jessica Willis, and Kirk Ballantyne in constructing the model and conducting the vibration tests is also greatly appreciated. The first writer would also like to acknowledge the financial support from the Gledden Fund for him to visit the University of Western Australia as a Gledden Senior Fellow.
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Information & Authors
Information
Published In
Journal of Structural Engineering
Volume 134 • Issue 5 • May 2008
Pages: 832 - 841
Copyright
© 2008 ASCE.
History
Received: May 30, 2006
Accepted: Oct 8, 2007
Published online: May 1, 2008
Published in print: May 2008
Notes
Note. Associate Editor: Ahmet Emin Aktan
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