Excitations of thermoelastic waves in plates by a pulsed laser

Acoustic Waves in Phononic Crystal Plates

“…The laser pulse, which is normally incident to the surface of the studied plates, generates the Lamb wave propagating along the x direction. The laser-generated force source f(t) is simulated as a delta function, which is perpendicular to the surface of the plate [25]. The elastic properties of the materials in the numerical calculations are the same as mentioned in above sections; and the thickness of the plates (L) of 1.0 mm.…”

Thermoelastic and Ablative Generation of Ultrasound: Source Effects

“…Laser generation of acoustic waves in the thermoelastic regime has been well characterized [4][5][6][7]. In the low irradiance regime, before vaporization takes place, the amplitude of laser generated acoustic waves shows a linear increase with pulse energy [8].…”

“…and Lv is the latent heat of vaporization. The boundary condition to be evaluated at the liquid-vapor interface is given as: (7) The vapor near the vapor-solid interface is not in translational equilibrium. This is achieved within a few mean free paths by collisions between particles in a Knudsen layer region.…”

An integrated method for material properties characterization based on pulsed laser generated surface acoustic waves

“…Most of theoretical approaches dealing with the generation and propagation of ultrasounds in solids focus on the search of analytical solutions [9][10][11][12][13][14][15]. The numerical approximation achieved by the aid of FEA in such complicated multiphysics problems, provides a convenient tool for the computational study of SAWs.…”