ON-LINE HEALTH MONITORING AND DAMAGE DETECTION OF STRUCTURES BASED ON THE WAVELET TRANSFORM

Presented herein is an experiment that aims to investigate the applicability of the wavelet transform to damage detection of a beam–spring structure. By burning out the string that is connected to the cantilever beam, high-frequency oscillations are excited in the beam–spring system, and there results an abrupt change or impulse in the discrete-wavelet-transformed signal. In this way, the discrete wavelet transform can be used to recognize the damage at the moment it occurs. In the second stage of damage detection, the shift of frequencies and damping ratios is identified by the continuous wavelet transform so as to ensure that the abrupt change or impulse in the signal from the discrete wavelet transform is a result of the damage and not the noise. For the random forced vibration, the random decrement technique is used on the original signal to obtain the free decaying responses, and then the continuous wavelet transform is applied to identify the system parameters. Some developed p version elements are used for the parametric studies on the first stage of health monitoring and to find the damage location. The results show that the two-stage method is successful in damage detection. Since the method is simple and computationally efficient, it is a good candidate for on-line health monitoring and damage detection of structures.

[1]  E. D. Denman,et al.  Analysis of the random decrement method , 1983 .

[2]  Erik A. Johnson,et al.  Phase I IASC-ASCE Structural Health Monitoring Benchmark Problem Using Simulated Data , 2004 .

[3]  Massimo Ruzzene,et al.  NATURAL FREQUENCIES AND DAMPINGS IDENTIFICATION USING WAVELET TRANSFORM: APPLICATION TO REAL DATA , 1997 .

[4]  A. Houmat,et al.  A SECTOR FOURIER p -ELEMENT APPLIED TO FREE VIBRATION ANALYSIS OF SECTORIAL PLATES , 2001 .

[5]  Yu Lei,et al.  Hilbert-Huang Based Approach for Structural Damage Detection , 2004 .

[6]  K. M. Liew,et al.  Application of Wavelet Theory for Crack Identification in Structures , 1998 .

[7]  Guido De Roeck,et al.  STRUCTURAL DAMAGE IDENTIFICATION USING MODAL DATA. I: SIMULATION VERIFICATION , 2002 .

[8]  Xiaomin Deng,et al.  Damage detection with spatial wavelets , 1999 .

[9]  Zhikun Hou,et al.  Application of Wavelet Approach for ASCE Structural Health Monitoring Benchmark Studies , 2004 .

[10]  Joseph Lardies,et al.  Identification of modal parameters using the wavelet transform , 2002 .

[11]  Branislav Titurus,et al.  Damage detection using generic elements: Part II. Damage detection , 2003 .

[12]  W. Staszewski.  IDENTIFICATION OF DAMPING IN MDOF SYSTEMS USING TIME-SCALE DECOMPOSITION , 1997 .

[13]  Branislav Titurus,et al.  Damage detection using generic elements: Part I. Model updating , 2003 .

[14]  A. Messina,et al.  On the continuous wavelet transforms applied to discrete vibrational data for detecting open cracks in damaged beams , 2003 .

[15]  Ingrid Daubechies,et al.  Ten Lectures on Wavelets , 1992 .

[16]  A. Messina.  Detecting damage in beams through digital differentiator filters and continuous wavelet transforms , 2004 .

[17]  R. B. Testa,et al.  Modal Analysis for Damage Detection in Structures , 1991 .

[18]  S. Quek,et al.  Sensitivity analysis of crack detection in beams by wavelet technique , 2001 .

[19]  Ser Tong Quek,et al.  Detection of cracks in cylindrical pipes and plates using piezo-actuated Lamb waves , 2005 .

[20]  S. R. Ibrahim.  Random Decrement Technique for Modal Identification of Structures , 1977 .

[21]  Andrew Y. T. Leung,et al.  Fourier p-elements for curved beam vibrations , 2004 .

[22]  Mohammad Noori,et al.  Wavelet-Based Approach for Structural Damage Detection , 2000 .