Theoretical Study on Laser-generated Ultrasound in the Structure with Continuous Changes of Near-surface Elastic Property
近表面弹性性质连续变化材料中激光声表面波的理论研究

Taking account of the continuous changes of the near-surface elastic property,a model of multiple gradient layers on the substrate is estabilished.An optimized finite element is developed to simulate the laser thermo-elastic generation and propagation of surface acoustic waves in the system.The effection of the differeot near-surface depth and elastic property to surface acoustic wave is studied.Furthermore,the regular phase velocity is attained and analyzed.