Damage Localization by Directly Using Incomplete Mode Shapes

Abstract

A sensitivity- and statistical-based method to localize structural damage by direct use of incomplete mode shapes is presented. The method is an extension of the multiple damage location assurance criterion (MDLAC), developed by Messina et al. by using incomplete mode shape instead of modal frequency. This approach makes use of the good sensitivity of mode shape to local damage. The damage detection strategy is to localize the damage sites first by using incomplete measured mode shapes, and then to detect the damage site and extent again by using measured natural frequencies, which have a better accuracy than mode shapes. A plane truss structure is analyzed as a numerical example to compare the performance of the proposed method with the multiple damage location assurance criterion. Results indicate that the new method is more accurate and robust in damage localization with or without noise effect.