Table of Contents
International Scholarly Research Notices
Volume 2014, Article ID 459097, 8 pages
http://dx.doi.org/10.1155/2014/459097
Research Article

Damage Location and Quantification Indices of Shear Structures Based on Changes in the First Two or Three Natural Frequencies

Mita Laboratory, Department of System Design Engineering, Keio University, 3-14-1 Hiyoshi, Kohoku-Ku, Yokohama 223-8522, Japan

Received 15 April 2014; Accepted 23 May 2014; Published 27 August 2014

Academic Editor: Constantin Chalioris

Copyright © 2014 Hien HoThu and Akira Mita. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

This study proposes damage detection algorithms for multistory shear structures that only need the first two or three natural frequencies. The methods are able to determine the location and severity of damage on the basis of damage location indices (DLI) and damage quantification indices (DQI) consisting of the changes in the first few squared natural frequencies of the undamaged and damaged states. The damage is assumed to be represented by a reduction in stiffness. This stiffness reduction causes a shift in the natural frequencies of the structure. The uncertainty associated with system identification methods for obtaining natural frequencies is also carefully considered. The methods are accurate and cost-effective means only requiring the changes in the natural frequencies.