Skip to main content

Advertisement

Official Journal of the Japan Wood Research Society

Journal of Wood Science Cover Image

A wavelet analysis-based approach for damage localization in wood beams

Article metrics

  • 139 Accesses

  • 15 Citations

Abstract

Free vibration testing was conducted to generate the first two mode shapes for damage detection in timbers. A wavelet transform was proposed to postprocess the mode shapes for damage pattern recognition. The wavelet used here was “db3.” The different damage severities, damage locations, and number of damaged areas were simulated by removing mass from intact beams. The results showed that the chosen wavelet db3 is suitable and that the wavelet coefficients are sufficiently sensitive to identify the existence of damage and its location in cases of different damage location, severity, and number. An edge distortion effect was apparent at the two computing edges where the wavelet coefficients were abnormally high. The wavelet coefficients showed dominant spikes around the damage locations and were zero everywhere else except the two computing edges. The dominant spikes coincided well with the damage location.

References

  1. 1.

    Yang XY, Ishimaru Y, Iida I, Urakami H (2002) Application of model analysis by transfer function to nondestructive testing of wood I: determination of localized defects in wood by the shape of the flexural vibration wave. J Wood Sci 48:283–288

  2. 2.

    Yang XY, Amano T, Ishimaru Y, Iida I (2003) Application of model analysis by transfer function to nondestructive testing of wood II: modulus of elasticity evaluation of sections of differing quality in a wooden beam by the curvature of the flexural vibration wave. J Wood Sci 49:140–144

  3. 3.

    Quek T, Wang Q, Zhang L, Ong KH (2001) Practical issues in the detection of damage in beams using wavelets. Smart Mater Struct 10:1009–1017

  4. 4.

    Hu CS, Afzal MT (2006) A statistical algorithm for comparing mode shapes of vibration testing before and after damage in timbers. J Wood Sci DOI 10.1007/s10086-005-0769-9

  5. 5.

    Michel M, Yves M, Georges O, Jean MP (2004) Wavelet toolbox for use with MATLAB. MathWorks, Natick, MA, pp 1–12

  6. 6.

    Yoshitaka S, Keisuke A, Nobuaki H, Shigeru K (2003) Wavelet transform for analysis of cutting sound of circular sawing. Mokuzai Gakkaishi 49:423–429

  7. 7.

    Yasuyoshi K, Zhong Z (2000) Evaluation of wood quality by wavelet analysis I. Wavelet analysis of the tapping tone of wood with a knot. Mokuzai Gakkaishi 46:197–202

  8. 8.

    Chui YH (1991) Simultaneous evaluation of bending and shear moduli of wood and the influence of knots on these parameters. Wood Sci Technol 25:125–134

Download references

Author information

Correspondence to Muhammad T. Afzal.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Hu, C., Afzal, M.T. A wavelet analysis-based approach for damage localization in wood beams. J Wood Sci 52, 456–460 (2006) doi:10.1007/s10086-005-0783-y

Download citation

Key words

  • Damage detection
  • Wavelet analysis
  • Wood beam
  • Nondestructive test