Damage localization in laminated composite plates using mode shapes measured by pulsed TV holography

Three methods for the damage localization of impact damage in laminated composite plates, based on their vibrational characteristics, are presented in this paper. These methods use double pulse TV holography with acoustic excitation for mode shapes acquisition and the differences in translations, rotations and curvatures. The rotations and curvatures are obtained by numerical differentiation of mode shapes translations using a differentiation/smoothing technique. The methods are applied to a carbon fiber reinforced epoxy rectangular plate, free in space, subjected to two cases of impact damage. It is shown that the method based on curvatures allows the localization of both cases of damage, which can be undetected by visual, X-ray or C-scan inspections. The best localizations are achieved by selecting and applying the method to the most changed mode.

[1]  J. Bevington,et al.  Differential operator based edge and line detection , 1987, ICASSP '87. IEEE International Conference on Acoustics, Speech, and Signal Processing.

[2]  Muneo Hori,et al.  A NUMERICAL STUDY OF STRUCTURAL DAMAGE DETECTION USING CHANGES IN THE ROTATION OF MODE SHAPES , 2002 .

[3]  Qian Kemao,et al.  Windowed Fourier transform for fringe pattern analysis. , 2004, Applied optics.

[4]  Cesar A. Sciammarella,et al.  A lens holographic-moiré technique to obtain components of displacements and derivatives , 1978 .

[5]  Giancarlo Pedrini,et al.  Double pulse-electronic speckle interferometry , 1993 .

[6]  Andrew P. Witkin,et al.  Uniqueness of the Gaussian Kernel for Scale-Space Filtering , 1986, IEEE Transactions on Pattern Analysis and Machine Intelligence.

[7]  Charles R. Farrar,et al.  Damage identification and health monitoring of structural and mechanical systems from changes in their vibration characteristics: A literature review , 1996 .

[8]  Qian Kemao,et al.  Windowed Fourier transform for fringe pattern analysis: addendum. , 2004, Applied optics.

[9]  Grant P. Steven,et al.  VIBRATION-BASED MODEL-DEPENDENT DAMAGE (DELAMINATION) IDENTIFICATION AND HEALTH MONITORING FOR COMPOSITE STRUCTURES — A REVIEW , 2000 .

[10]  Mário Vaz,et al.  An improved mixed numerical-experimental method for stress field calculation , 2007 .

[11]  M. Takeda,et al.  Fourier-transform method of fringe-pattern analysis for computer-based topography and interferometry , 1982 .

[12]  Arun Kumar Pandey,et al.  Damage detection from changes in curvature mode shapes , 1991 .

[13]  Cesar A. Sciammarella,et al.  Holographic interferometry applied to the solution of a shell problem , 1974 .

[14]  Edward Sazonov,et al.  Optimal spatial sampling interval for damage detection by curvature or strain energy mode shapes , 2005 .

[15]  Yimei Zhu,et al.  Deterministic phase unwrapping in the presence of noise. , 2003, Optics letters.

[16]  C. M. Mota Soares,et al.  Identification of material properties of composite plate specimens , 1993 .