Identification of structural damage using S-transform from 1D and 2D mode shapes

Abstract

An improvement of vibration-based damage identification in structures attracted much attention over the last decades. Many of the developed algorithms to-date, like those based on wavelet transforms (WTs), reveal high sensitivity to damage, however suffer from numerous drawbacks, which include significant dependency of a damage detectability on selection of a basis function or the boundary effect. This paper presents a novel alternative approach for damage identification in beams and plates based on the S-transform, which combines numerous advantages of the short-time Fourier transform and an ability of multiresolution analysis of WTs. The efficiency of the proposed approach was tested and validated on 1D and 2D mode shapes of various composite structures and various types of damage obtained both from numerical simulations and experimental studies. The obtained results confirmed high sensitivity of the approach based on the S-transform to structural damage as well as revealed full reduction of the boundary effect.