STRUCTURAL DAMAGE DETECTION BY A SENSITIVITY AND STATISTICAL-BASED METHOD

Abstract During the last 20 years, the development of experimental modal analysis techniques has facilitated the accurate measurement of modal parameters in many types of structure. Alongside this work, several methods have been developed to detect structural damage by using location-dependent changes in the modal parameters. The paper extends the authors' work on a correlation coefficient termed the Multiple Damage Location Assurance Criterion (MDLAC) by introducing two methods of estimating the size of defects in a structure. Their effectiveness is illustrated using numerical data for two truss structures and both location and sizing algorithms are validated experimentally using a three-beam test structure. The paper also introduces a means of improving the computational efficiency of the damage location algorithm. The MDLAC approach offers the practical attraction of only requiring measurements of the changes in a few of the structure's natural frequencies between the undamaged states and is shown to provide good predictions of both the location and absolute size of damage at one or more sites.