Buildup panels for the commercial aircraft fuselage subjected to the axial com pression load are studied by both experimental and theoretical methods. An integ ral panel is designed with the same overall size and weight as the buildup str ucture

and finite element models (FEMs) of these two panels are established. Ex perimental results of buildup panels agree well with the FEM results with the nonliearity and the large deformation

so FEMs are validated. FEM calculation results of these two panels indicate that the failure mode of the i ntegral panel is different from that of the buildup panel

and the failure loa d increases by 184％ up to postbuckling. Furthermore

the integral structure is optimized by using the multiisland genetic algorithm and the sequential quadratic progr amming. Compared with the initial design

the optimal weight is reduced by 87 ％ and the strength is unchanged.