EACS 2016 paper - A new approach to identification of cracks in beams and experimental verification

2017-03-28T15:19:00Z (GMT) by Chuanchuan Hou Yong Lu
EACS 2016 Paper No. 168

Cracking is a common type of damage in structural beams. Existing methods for the detection of cracks in beams are most commonly based on representing a crack by a reduction of the bending stiffness over a certain segment. While such representation may be acceptable for slender beams, it can be problematic for relatively thick beams which are typical in civil engineering structures. In the present study an explicit cracked beam element model is adopted, in which the effect of the crack is comprehensively described by a cracked stiffness matrix relating to the crack location and the crack depth. The cracked beam element model is implemented in a finite element model updating framework for the identification of the crack parameters. This paper provides an overview of this new crack identification approach and the verification of the effectiveness of the method from laboratory experiments. In the experimental verification, cracked beam specimens have been tested to extract the modal frequency and mode shape data, and these are compared with the predictions using the cracked beam element model. The measured modal data are also employed to carry out (inverse) crack identification to further verify the effectiveness of using the cracked beam element model for crack damage identification.