Impact imaging of aircraft composite structure based on a model-independent spatial-wavenumber filter

Lei Qiu, Bin Liu, Shenfang Yuan, Zhongqing Su

Research output: Journal article publicationJournal articleAcademic researchpeer-review

69 Citations (Scopus)

Abstract

The spatial-wavenumber filtering technique is an effective approach to distinguish the propagating direction and wave mode of Lamb wave in spatial-wavenumber domain. Therefore, it has been gradually studied for damage evaluation in recent years. But for on-line impact monitoring in practical application, the main problem is how to realize the spatial-wavenumber filtering of impact signal when the wavenumber of high spatial resolution cannot be measured or the accurate wavenumber curve cannot be modeled. In this paper, a new model-independent spatial-wavenumber filter based impact imaging method is proposed. In this method, a 2D cross-shaped array constructed by two linear piezoelectric (PZT) sensor arrays is used to acquire impact signal on-line. The continuous complex Shannon wavelet transform is adopted to extract the frequency narrowband signals from the frequency wideband impact response signals of the PZT sensors. A model-independent spatial-wavenumber filter is designed based on the spatial-wavenumber filtering technique. Based on the designed filter, a wavenumber searching and best match mechanism is proposed to implement the spatial-wavenumber filtering of the frequency narrowband signals without modeling, which can be used to obtain a wavenumber-time image of the impact relative to a linear PZT sensor array. By using the two wavenumber-time images of the 2D cross-shaped array, the impact direction can be estimated without blind angle. The impact distance relative to the 2D cross-shaped array can be calculated by using the difference of time-of-flight between the frequency narrowband signals of two different central frequencies and the corresponding group velocities. The validations performed on a carbon fiber composite laminate plate and an aircraft composite oil tank show a good impact localization accuracy of the model-independent spatial-wavenumber filter based impact imaging method.
Original languageEnglish
Pages (from-to)10-24
Number of pages15
JournalUltrasonics
Volume64
DOIs
Publication statusPublished - 1 Jan 2016

Keywords

  • Composite structure
  • Impact imaging
  • Lamb wave
  • Linear piezoelectric sensor array
  • Spatial-wavenumber filter

ASJC Scopus subject areas

  • Acoustics and Ultrasonics

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