An Inverse Analysis in Ultrasonic Testing of Closed Cracks

Masumi Saka, Yasuyuki Takanaka

Research output: Contribution to journalArticlepeer-review

3 Citations (Scopus)


An inverse problem to determine the crack size in nondestructive testing of closed cracks by ultrasonics is analyzed. Ultrasonic testing using a normal incident longitudinal wave is treated for sizing a crack which exists parallel to the measuring surface. Ultrasonic waves pass through the closed crack surfaces, and hence usual techniques applied to open cracks cannot be applied to size closed cracks. Reflection of the wave at the closed crack surface is analyzed based on dynamic elasticity by introducing a model of crack closure with unknown parameters. The unknown parameters are determined along with the unknown location of the crack tip by the inverse analysis, which compares the intensity of the reflected wave obtained through both theory and experiment. The ultrasonic measurements for a cracked specimen under several compressive loadings have shown that the present analysis offers a powerful tool for precise sizing of closed cracks.

Original languageEnglish
Pages (from-to)1736-1743
Number of pages8
JournalTransactions of the Japan Society of Mechanical Engineers Series A
Issue number528
Publication statusPublished - 1990


  • Closed Crack
  • Fracture
  • Inverse Analysis
  • Longitudinal Wave
  • Model of Crack Closure
  • Reflection
  • Ultrasonic Testing

ASJC Scopus subject areas

  • Materials Science(all)
  • Mechanics of Materials
  • Mechanical Engineering


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