Importance of Acoustic Chaos in Sonic IR Imaging NDE
2004; American Institute of Physics; Linguagem: Inglês
10.1063/1.1711663
ISSN1935-0465
Autores Tópico(s)Ultrasonics and Acoustic Wave Propagation
ResumoIn the Sonic IR imaging NDE technique, a short ultrasonic pulse (typically a fraction of a second) is applied to the target to excite the defects to heat up, while an infrared camera images the time evolution of the heating effect to identify the defective areas in the target. Although the ultrasonic sources we use in our systems ordinarily provide only a single frequency, the non‐linear coupling between the ultrasonic transducer tip and the target can cause acoustically chaotic vibrations in the target, namely producing other frequency components that are multiples of rational fractions of the driving frequency. The vibrational behavior is monitored by laser vibrometers. We discovered that this acoustic chaos enhances the IR signal of defects. In this paper, we present examples of the generation of chaotic vibration from the application of an ultrasonic excitation pulse when coupled non‐linearly to a specimen under inspection by sonic IR imaging.
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