A simplified one-dimensional model of thermoelastic vibration in multilayered structures generated by the photoacoustic effect has been developed. When an intentity-modulated laser beam is incident on a multilayer, periodical temperature variation is excited by the optical absorption and it is propagated due to the thermal diffusion. The temperature distribution is calculated by solving the thermal diffusion equation, considering the boundary conditions at each interface within the multilayer. If there is asymmetrical distribution of the temperature in depth direction, bending motion will be excited by the thermal expansion. Therefore we assume that the amplitude and phase of the bending vibration is represented by those of the temperature moment. In a preliminary verification of this theory, the modulation frequency dependence of the temperature moment in a five layered structure of (air/Cu/air/Cu/air) was calculated and it was compared with experimental results. A good agreement was obtained.
|Number of pages||7|
|Journal||Kikai Gijutsu Kenkyusho Shoho/Journal of Mechanical Engineering Laboratory|
|Publication status||Published - 1991 Jul 1|
ASJC Scopus subject areas
- Mechanical Engineering