Experimental comparison of structural damage detection methods

Abstract

Recently, Structural health monitoring and damage detection has received a considerable amount of interest. Also many detecting techniques have been developed for a few decades. In order to use these various damage detection methods in real structures, it is important to know the characteristics and applicability of them. In this study, methods using natural frequency, mode shape and wave propagation are compared experimentally for their application. For the experimental comparison, three damage detection methods are tested with the same damage cases and environmental conditions. Aluminum beams, 40mm wide and 4mm thick with a clear span of 600mm under fixed-free boundary conditions are used. Damages are given at three different locations, 1/4, 2/4, 3/4 of the beam length starting from the fixed end. The damage sizes are 5%, 10%, 20% and 30% at each damage location. Unlike numerical calculation of the compared methods, it is hard to detect small damages by any compared method because of practical and technical problems. Some errors are unavoidable and some others can be reduced by changes of experimental setup. These factors of errors are also discussed in this study.