Experiment and Finite Element Simulation for Laser Ultrasonic Measurement of the Elastic Constants of Metal Materials

doi:10.12068/j.issn.1005-3026.2018.09.029

Abstract

Abstract: The elastic constants of aluminum plates were inversed by the wave velocity of various modal ultrasonic waves induced by lasers. In the experiment， the pulse laser was focused into the line source to induce the ultrasonic wave on the surface of the aluminum plate， and the dual channel non-contact method was used to receive the time domain information of the surface wave and then its velocity was measured. In the finite element analysis， the laser was equivalent to the pulse load that is satisfied with the Gaussian distribution both in time and space. A thermal coupling analysis model was built to simulate the process of laser induced ultrasonic. The time domain information of the ultrasonic signals were received to calculate the surface wave’s and longitudinal wave’s velocities. Then the elastic constants of aluminum plates were obtained by using the acoustic elastic equation. The numerical results agreed with the theoretical values， which indicates that the established laser ultrasonic model can effectively simulate the physical process of ultrasonic induced by lasers， and provide the basis for further studies on the mechanical properties of the materials by laser ultrasonic techniques.

Key words: laser ultrasonic, elastic constants, finite element simulation, surface wave, longitudinal wave

CLC Number:

O341

ZHAN Yu， LIN Zhong-ya， LIU Chang-sheng. Experiment and Finite Element Simulation for Laser Ultrasonic Measurement of the Elastic Constants of Metal Materials[J]. Journal of Northeastern University Natural Science, 2018, 39(9): 1363-1368.

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