Non-contact Measurement of Elastic Modulus by using Laser Ultrasonic
http://link.springer.com/article/10.1007/s12541-015-0118-x
Non-contact measurement of elastic modulus by using laser ultrasound
Abstract
Non-contact measurement of elastic modulus is necessary for the in-line assessment of material in harsh environments such as high temperature. In this paper, a fully non-contact method to measure elastic modulus is proposed based on the laser ultrasonic technique (LUT) that uses a short-pulsed laser to generate ultrasound and the other laser coupled to an interferometer using a photorefractive crystal to detect the ultrasonic wave displacement. Basically, this method measures velocities of shear wave and longitudinal wave to obtain the elastic modulus. The uniqueness is that the velocity of shear wave is measured in the thermo-elastic regime first and then the velocity of longitudinal wave is measured in the ablation regime. This is because the strong mode of generated ultrasound is the shear wave in the thermo-elastic regime while the longitudinal wave in the ablation regime. Regime change can be achieved simply by switching the laser power, with no change in the measurement setup. In order to demonstrate the usefulness of the proposed method, the elastic modulus of aluminum casting alloy has been measured and the results were compared with a conventional contact method and a destructive tensile test. They showed good agreement with each other, which verified the usefulness of the proposed noncontact elastic modulus measurement method.
Keywords
Elastic modulus Laser ultrasound Non-contact Non-destructive- 한국도로공사 교통데이터 공모전 - 대한교통학회 회장상 수상 (김진수)
- 한국ITS학회 - 우수논문상
- 비파괴검사학회지 우수 논문상 (김정석, 남태형, 최성호, 장경영)
- 비파괴검사학회지 - 우수논문상
- 비파괴검사학회지 - 우수 논문상
- 대한기계학회 - 우수 학생 논문상
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- KSME-SEMES 오픈 이노베이션 챌린지 동상 수상 - 윤성희
- JMST - JMST Contribution Award