VIBRATION OF GEOMETRICALLY IMPERFECT PANELS SUBJECTED TO THERMAL AND MECHANICAL LOADS

The results of a study of the vibration response of transversely isotr opic flat and curved panels subjected to temperature fields and to mec hanical loads into the postbuckling load range are presented, The resu lts were obtained using a higher-order transverse-shear-deformation th eory of shallow shells that includes the effects of geometric nonlinea rities and initial geometric imperfections, The results focus on the i nteraction between the temperature field, the applied mechanical load, and the fundamental frequency associated with small vibrations about the prebuckling and postbuckling equilibrium states. Results are prese nted for a wide range of temperatures and mechanical load magnitudes a nd of geometric parameters. The results show that transverse-shear fle xibility has a significant effect on the analytical prediction of pane l response and that the fundamental frequency of a panel may be substa ntially overestimated in the prebuckling load range and underestimated in the postbuckling load range, Results are also presented that indic ate that the fundamental frequency of flat panels generally increases as the initial geometric imperfection amplitude increases for both the prebuckling and postbuckling load ranges, The results, however, also indicate that the fundamental frequency of curved panels generally dec reases in the prebuckling load range and increases in the postbuckling load ranges.