Detection of subharmonics in ultrasonic inspection of contact surfaces under compression

Issue title: Selected Papers from the 15th International Symposium on Applied Electromagnetics and Mechanics (ISEM 2011)

Article type: Research Article

Authors: Kurihara, Kenji^a | Naitou, Keiichi^a | Sugiura, Toshihiko^{a; *}

Affiliations: [a] Mechanical Engineering, Keio University, Yokohama, Japan

Correspondence: [*] Corresponding author: Toshihiko Sugiura, Mechanical Engineering, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, 223-8522 Yokohama, Japan. Tel.: +81 455 631141; Fax: +81 455 661495; E-mail: sugiura@mech.keio.ac.jp

Abstract: Detection and sizing of a closed crack in structures are difficult by conventional ultrasonic testing. One of promising alternative methods is nonlinear ultrasonic testing which detects subharmonic responses from a closed crack. This study investigates generation of subharmonics at contact surfaces of two specimens, modeling a closed crack, under ultrasonic radiation. Experiments of ultrasonic inspection were carried out by preparing different kinds of surface roughness of the specimens and also by changing compression force acting on the two contacting specimens. Our experimental results show some subharmonic responses from the contact surfaces, which can be influenced by the contact pressure and the contact surface roughness.

Keywords: Nondestructive testing, nonlinear ultrasonic, subharmonics

DOI: 10.3233/JAE-2012-1466

Journal: International Journal of Applied Electromagnetics and Mechanics, vol. 39, no. 1-4, pp. 237-243, 2012