Group delay measurements using modally selective Lamb wave transducers for detection and sizing of delaminations in composites

G. Petculescu*, Sridhar Krishnaswamy, Jan Drewes Achenbach

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

43 Scopus citations

Abstract

A group delay measurement technique is proposed using modally selective Lamb wave transducers for the detection and sizing of delaminations in unidirectional and cross-ply composites. Unlike amplitude or energy based Lamb wave methods, this method is insensitive to transducer coupling. Specifically, modally selective array transducers are used to generate the lowest antisymmetric A0 Lamb mode in a zone with minimal dispersion. The change in the modal group velocity is used as a damage indicator while the accumulated time delay of the traveling ultrasonic wavepacket is used for size estimation of the delaminations. The results are repeatable and consistent, suggesting time delay as a reliable damage parameter for quantitative monitoring of delaminations and impact damage in composites.

Original languageEnglish (US)
Article number015007
JournalSmart Materials and Structures
Volume17
Issue number1
DOIs
StatePublished - Feb 1 2008

ASJC Scopus subject areas

  • Signal Processing
  • Civil and Structural Engineering
  • Atomic and Molecular Physics, and Optics
  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanics of Materials
  • Electrical and Electronic Engineering

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