Pre‐ and postbuckling response of curved, thin, composite panels with cutouts under compression

Analytical predictions of the postbuckling response of curved composite panels are difficult, especially under in‐plane compression, because of the presence of snap‐back with a steep negative slope beyond the bifurcation point. In this study, the pre‐ and postbuckling response of curved laminated panels with cutouts is investigated by developing a new finite element based on the free formulation. This trianguiar, flat, shell element, in conjunction with the updated Lagrangian form of the co‐rotational approach, accounts for the coupling terms arising from general material anisotropy, as well as large displacements and rotations. The analysis predictions correlate well with the corresponding experimental data available in the literature. Review of the studies in this subject area reveal that none of the available methods, including the STAGS‐C1 finite element program, is capable of providing the full description of the postbuckling phenomenon beyond bifurcation for curved composite panels with small cutouts.