Vibration testing based on impulse response excited by laser ablation

Itsuro Kajiwara, Naoki Hosoya

Research output: Contribution to journalArticle

33 Citations (Scopus)

Abstract

This paper proposes an innovative vibration testing method based on impulse response excited by laser ablation. In conventional vibration testing using an impulse hammer, high-frequency elements of over tens of kilohertz are barely present in the excitation force. A pulsed high-power YAG laser is used in this study for producing an ideal impulse force on a structural surface. Illuminating a point on a metal with the well-focused YAG laser, laser ablation is caused by generation of plasma on the metal. As a result, an ideal impulse excitation force generated by laser ablation is applied to the point on the structure. Therefore, it is possible to measure high-frequency FRFs due to the laser excitation. A water droplet overlay on the metal is used to adjust the force magnitude of laser excitation. An aluminum block that has nine natural frequencies below 40 kHz is employed as a test piece. The validity of the proposed method is verified by comparing the FRFs of the block obtained by the laser excitation, impulse hammer, and finite element analysis. Furthermore, the relationship between accuracy of FRF measurements and sensitivity of sensors is investigated.

Original languageEnglish
Pages (from-to)5045-5057
Number of pages13
JournalJournal of Sound and Vibration
Volume330
Issue number21
DOIs
Publication statusPublished - 2011 Oct 10

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ASJC Scopus subject areas

  • Acoustics and Ultrasonics
  • Condensed Matter Physics
  • Mechanical Engineering
  • Mechanics of Materials

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