Modeling of non-equilibrium deformation in a double-layered thin film during ultrashort laser heating

An ultrafast thermoelasticity based on hyperbolic two-step heat conduction model with electron-phonon interaction is applied to investigate thermomechanical response on an infinite double-layered metal film impacted under femtosecond laser pulses by using finite element method (FEM). Finite element governing equations are established and solved in time domain directly. The effect of temperature dependence of the coupling coefficient G between electron and lattice is considered, and the results, including electron temperature, lattice temperature, displacements and stresses are presented graphically and analyzed. In addition, characteristics of stresses evolution and displacements development in the thin film are obtained. Finally, the influences of hot-electron blast force on displacements and stresses are studied.