Numerical simulation of laser-generated ultrasonic waves in layered plates

Thermo-elastic laser-generated ultrasound in layered plates has been studied using the finite element method, after considering the temperature dependence of the thermo-physical parameters of the materials. It is confirmed that the temperature dependence of the thermo-physical parameters has a significant influence on thermo-elastically generated ultrasound with high frequencies. Numerical results calculated in two kinds of two-layer system indicate that the features of the surface acoustic wave (SAW) generated are dependent on the thickness of the surface layer. Numerical results from three-layer systems indicate that the skimming surface longitudinal wave is sensitive to the thickness of the surface layer, while the SAW is much more sensitive to the thickness of the bonding layer, and it can be used to extract the thickness parameter of the bonding layer in an effective way.