Thermomechanical effect induced by pulse laser heating

Summary form only. A generalized solution to thermoelastic plane waves in a semi-infinite solid induced by pulse laser heating is formulated in the form of Fourier series. The solution takes into account the non-Fourier effect in heat conduction and the coupling effect between temperature and strain rate, which play significant roles in ultra-short pulse laser heating. Based on this solution, calculations are conducted to study thermoelastic waves induced by different laser parameters. It was found that with the same maximum surface temperature increase, the shorter the pulse width, the stronger the stress. The non-Fourier effect causes a higher surface temperature increase, but a weaker stress wave. In addition, for the first time, it is found that a second stress wave is formed and propagates with the same speed as the temperature wave. Strong dissipation causes the temperature wave and the second stress wave only appear within a short distance from the surface. A time delay can be observed between the surface displacement and the laser pulse during femtosecond laser heating. In contrary, surface displacement and heating occur simultaneously in nano- and picosecond laser heating.