The research of Lamb wave dispersion removal by linear reconstruction of phase spectrum
Received:February 13, 2020  Revised:July 08, 2020
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DOI:10.7511/jslx20200213002
KeyWord:Lamb wave  linear reconstruction of phase spectrum  dispersion  array beamforming and damage imaging  damage location
  
AuthorInstitution
徐彩军 江苏省建筑工程质量检测中心有限公司, 南京
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Abstract:
      Lamb wave is widely used for damage detection in plate and shell structures, but the dispersion of Lamb wave makes it difficult to accurately extract the time-of-flight information of the damage scattering signals in a plate structure, that affects the array beamforming damage imaging algorithm for damage imaging effect and precision.Linear reconstruction of phase spectrum is proposed, by expanding the phase spectrum at the center frequency and then linearizing it, which can effectively remove the dispersion in the excitation signal.This method guarantees that the signal components at the center frequency do not change, which lays the foundation for the research of array beamforming damage imaging algorithm for accurate damage imaging.Numerical simulation and experiment methods were used to verify the effect of the proposed linear reconstruction of phase spectrum method to remove the dispersion, further combined with the array beamforming damage imaging method to analyze the effect and accuracy of damage imaging location.The result shows that the adopted dispersion removal method can improve the signal-to-noise ratio of the scattered signals, and improve the result and accuracy of the array beamforming damage imaging method on the location of damage imaging.