Indian Journal of Science and Technology
Year: 2009, Volume: 2, Issue: 12, Pages: 25-28
T. Pramila, Anita Shukla, N.N. Kishore1 and V. Raghuram1
Dept. of Physics, Christ Church College, Kanpur;
1Indian Institute of Technology Kanpur, Kanpur, India
*Author for the correspondence:
Dept. of Physics, Christ Church College,
E-mail: [email protected]
This paper deals with the determination of the elastic constants of aluminium from the analysis of laser generated ultrasonic bulk waves. A pulsed Nd:YAG laser (1064 nm) is used for ultrasonic generation in a thick stepped Al sample and a He-Ne laser is used for heterodyne detection of the generated signals. Ultrasonic signals obtained at epicenter and at off-epicenter position of the detection points are analyzed using wavelet transforms. Here the identification and of pressure as well as shear waves and the estimation of their velocities are done successfully. From the estimated velocities the elastic constants (Young’s modulus, shear modulus, bulk modulus, Lames constant and Poisson’s ratio) are calculated. The agreement of these constants with the standard values confirms the identification of shear waves at off-epicenter position. The work presented in this paper brings out the applicability of the study of laser generated bulk waves for the determination of elastic constants of any bulk material.
Keywords: Laser based ultrasonics, wavelet transforms, pressure waves, shear waves, elastic constants, Al.
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