This Article Full Text (PDF) References Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Alert me to new issues of the journal Add to Saved Citations Download to citation manager Request Permissions Request Reprints Add to My Marked Citations Citing Articles Citing Articles via ISI Web of Science (2) Citing Articles via Google Scholar Google Scholar Articles by Wang, J. Articles by Qiao, P. Search for Related Content Social Bookmarking                   What's this?

Improved Damage Detection for Beam-type Structures using a Uniform Load Surface

Department of Civil, Construction, and Environmental Engineering The University of Alabama, Tuscaloosa, AL 35487-0205, USA

Pizhong Qiao

Department of Civil and Environmental Engineering, Washington State University, Pullman, WA99164-2910, USA, qiao{at}wsu.edu

A combined analytical and experimental study is conducted to develop efficient and effective damage detection techniques for beam-type structures. Unlike many other vibration-based damage detection methods, in which the mode shapes are often chosen to retrieve damage information, the uniform load surface (ULS) is employed in this study due to its less sensitivity to ambient noise. In combination with the ULS, two new damage detection algorithms, i.e., the generalized fractal dimension (GFD) and simplified gapped-smoothing (SGS) methods, are proposed. The GFD method is developed by modifying the conventional definition of fractal dimension. By using a moving window, the GFD of ULS can be obtained for each sampling point, and due to the irregularity of ULS introduced by the damage, a peak exists on the GFD curve indicating the location of the damage. Not only does such a peak at the GFD curve locate the damage, but also it reveals the relative size of the damage. The SGS method is also proposed to take advantage of the simple deformation shape of ULS. Both methods are then applied to the ULS of cracked and delaminated beams obtained analytically, from which the damage location and size are determined successfully. Based on the experimentally measured curvature mode shapes, both the GFD and SGS methods are further applied to detect three different types of damage in carbon/epoxy composite beams. The successful detection of damage in the composite beams demonstrates that the new techniques developed in this study can be used efficiently and effectively in damage identification and health monitoring of beam-type structures.

Key Words: structural health monitoring • damage detection algorithm • generalized fractal dimension • simplified gapped smoothing method • vibration • mode shapes • composites • delamination • crack

CiteULike    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?