Numerical simulations on buckling failure of preloaded cylindrical shell irradiated by high power laser beam

With finite-element software ANSYS 7.0 and simple thermal-mechanical coupling constitutive relations, the buckling failure of preloaded shell irradiated by high power laser beam was studied by numerical simulations. Buckling mode and buckling critical loading were analysed for different pre-loading conditions. The influences of laser intensity, beam irradiation time, preloading conditions, shape and geometric parameters of shell on the buckling mode were discussed. The numerical results showed that: (1) the buckling deformation of the shell was concentrated on the area of laser spot and the radial buckling was the main buckling mode, (2) a linear relationship between buckling eigenvalue and the maximum temperature at the center of laser spot was approached, (3) the buckling failure of shell was attributed to the coupling effect of the material softening and the radial deformation in the laser spot, and hence to raise the stiffness of the material would enhance the ability of anti-irradiation of structure substantially, (4) the effect was more obvious under internal preloading for different shapes of shell, and the cylindrical shell had larger buckling eigenvalue and higher security.