Abstract
Laser generation of Lamb wave in a thin plate is studied numerically. To this purpose, the EFIT (Elastodynamic Finite Integration Technique) is extended to incorporate coupled dynamic thermoelasticity. The energy input by the laser is modeled as a line heat source in the heat conduction equation. Based on this technique, the influence of the coupling term in the heat conduction equation on the temperature variation and the generated ultrasound waveform is evaluated. Moreover, Lamb wave generation behavior due to multiple laser beams is analyzed. It is shown that as the number of line sources increases, the generated AO-mode Lamb wave tends to acquire a narrow-band feature around a frequency determined by the interval of line sources and the dispersion curve of Lamb waves.
