THEORY OF THE THERMOELASTIC GENERATION OF MECHANICAL VIBRATIONS IN INTERNALLY STRESSED SOLIDS BY LASER-RADIATION

An investigation was made of the behavior of transient deformations in solids with internal stresses exposed to time-modulated laser radiati on. The nonlinear theory of thermoelasticity is used to propose a mode l for the excitation of mechanical stresses which takes account of the stress dependence of the thermoelastic coupling parameter. An express ion is derived for the electric signal recorded by a piezoelement when mechanical vibrations are generated in a uniformly deformed sample. T he results are compared with existing experimental data and show quali tative agreement. (C) 1998 American Institute of Physics.