Crack identification in plates using 1-D discrete wavelet transform

Abstract

In the present work, the defect detection while using Discrete Wavelet Transform in rectangular plate structures is investigated. The plate bending is described by using the Boundary Element Method with boundary integral equations formulated in a modified simplified approach. The boundary elements of a constant type in a non-singular approach are implemented. Defects are introduced by additional edges forming slots or holes in relation to the basic plate domain. Estimation of the defect position is performed while using wavelet coefficients of curvature and deformation signals as well as a newly proposed moving variance estimator.

Application of Wavelet Transform to Damage Identification in the Steel Structure Elements

“…The selection of this wavelet results from the authors' previous experience in detecting damages in various types of structures [4,5,7]. The basic Daubechies wavelet (mother) and scaling wavelet (father) are shown in Figure 2.…”

“…Wavelet transform was first used to detect defects in the mid-1990s, in which [2] the vibration signal obtained in a computer-simulated experiment for a beam with a crack was analyzed. Numerically simulated experiments were also presented in [3][4][5], in which the effectiveness of the WT in detecting 2 of 12 damages in plates, beams and trusses, based on the analysis of static or dynamic structural response signals, was demonstrated. Experimental verification, conducted with the use of a laser scanning vibrometer, of numerical tests for eight vibration modes of the cantilever beam with cuts of 5, 10 and 20% of the beam height is presented in [6].…”

Artificial Neural Networks for Inverse Problems in Damage Detection using Computational and Experimental Eddy Current

“…Thus, the toughness is often measured as a point value and characterized by a parameter such as the Stress Intensity Factor (SIF) or the Energy Release Rate (G) at the crack initiation. The first fracture toughness test standard ASTM E399 was developed to determine the point value of plane strain fracture toughness near to the onset of crack initiation K Ic [2,3].…”