Damage detection methods in bridges through vibration monitoring: evaluation and application

In this thesis, a detailed analysis of the most important vibration-based damage detection methods applied to bridge structures is addressed. Special attention is focused on those methods capable to detect damage only with information provided from a damage stage of the structure. For that purpose, methods based on wavelet analysis, curvature of the mode shapes and changes in the flexibility and stiffness matrices of the structure methods are selected. These methods are easy to implement to bridge structures for its on-line structural evaluation or for its evaluation at different damage stages. The selected damage detection methods are evaluated under three different cases: (1) damage scenarios are simulated on numerical methods for cracked beam structures; (2) experimental tests are carried out in the laboratory with metallic and concrete beams strengthened with CFRP laminates; (3) real-scale bridge structures are tested under different damage scenarios. To do an accurate simulation of the dynamic behaviour of cracked bridges, some of these methods are investigated and evaluated on beams with rectangular cross sections. Later, the methods are generalized to be applicable to more complex structures, like bridges, and to other cross sections, as in composite bridges. From the research done here, it is concluded that the performance of the damage detection methods depends of several factors, for example, the number of sensors located near the damage zones, level of noise present in the acquired dynamic response, location, extension and severity of the damage. Finally, it is recommended to do the process of damage identification in the bridge using the selected group of damage detection methods where successful damage detection is obtained when more than one method clearly indicates damage.

Name thesis:degree_name

Doutoramento em Engenharia Civil

Year dc:date.issued

2008

Author dc:creator

• Estrada, Rolando Salgado

Advisors dc:contributor.advisor

• Cruz, Paulo J. S.
• Ayala Milián, Amado Gustavo

Statement dc:rights

• openAccess

Language dc:language.iso

eng

Handle dc:identifier.uri

https://hdl.handle.net/1822/9023

OAI record oai:identifier

http://repositorium.sdum.uminho.pt/oai/request?verb=GetRecord&metadataPrefix=dim&identifier=oai%3Arepositorium.uminho.pt%3A1822%2F9023