| Autor: |
M. Zhang, J. D. Achenbach, I. N. Komsky |
| Rok vydání: |
1996 |
| Předmět: |
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| Zdroj: |
Acoustical Imaging ISBN: 9781461346876 |
| DOI: |
10.1007/978-1-4419-8772-3_121 |
| Popis: |
Thin-walled multi-layered structures, with sealants in-between the layers, may develop interface defects on deeper interfaces. For nondestructive inspection it is desirable to generate a visual indication of such defects by an ultrasonic imaging technique. For aircraft structures the imaging must generally be done with one-sided access only and by the use of contact transducers. A conventional normal incidence reflection technique is not practical because the interference of multiple reflections at the interfaces makes it difficult to extract relevant signals for image generation. In this paper these difficulties have been overcome by the use of an oblique pitch-catch transducer configuration. The parameters in such a configuration are wedge angles for the contact transducers, center frequencies, and the spacing of the transducers in the pitch-catch configuration. These parameters must be selected correctly for optimal penetration into the multi-layered structure and optimal reception of ultrasonic signals. The theoretical background of the technique is discussed and images are presented of second layer corrosion in wing structures. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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