Evaluation of crack orientation using fatigue crack-induced contact acoustic nonlinearity

Kai Wang, Zhongqing Su, Shenfang Yuan

Research output: Chapter in book / Conference proceedingConference article published in proceeding or bookAcademic researchpeer-review


Based on the two-dimensional (2D)1 and three-dimensional (3D)2 analytical models previously developed for interpreting the contact acoustic nonlinearity (CAN) generated due to the modulation from a "breathing" crack in solid media on propagating guided ultrasonic waves (GUWs), this study proposes a new characterization approach, able to orientate a fatigue crack, even when the crack is at its embryo stage. CAN embodied in the scattered Lamb waves and shear horizontal (SH) waves converted from incident GUWs is extracted upon interaction with fatigue cracks, and the unique scattering pattern of CAN is associated with crack slant via the 3D analytical models, whereby the orientation of a fatigue crack can be pinpointed, without making a reference to the baseline signal. Experimental validation of the characterization approach is implemented, in which an undersized fatigue crack is orientated accurately and visualized in the image.

Original languageEnglish
Title of host publicationHealth Monitoring of Structural and Biological Systems XII
EditorsTribikram Kundu
ISBN (Electronic)9781510616967
Publication statusPublished - 1 Jan 2018
EventHealth Monitoring of Structural and Biological Systems XII 2018 - Denver, United States
Duration: 5 Mar 20188 Mar 2018

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
ISSN (Print)0277-786X
ISSN (Electronic)1996-756X


ConferenceHealth Monitoring of Structural and Biological Systems XII 2018
Country/TerritoryUnited States


  • breathing crack
  • contact acoustic nonlinearity
  • fatigue crack orientation
  • guided ultrasonic waves

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering

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