Buckling And Postbuckling Research Of Stiffened Composite Panel Containing Damage

The stiffened composite panel, as a typical engineering structure in aviation, aerospace, machinery and many other fields, has been more and more applications. In actual use, the stiffened composite panel is often subject to compression, and buckling instability is the most common failure mode. Stiffness composite panels have a high post-buckling strength capacity, which is needed for a reasonable use in design. The damage in the stiffeners and skin often occurs. Therefore, in consideration of damage, how to accurately determine the critical buckling load and the post-buckling strength capacity of stiffened composite panels is one of the key problems in composite material structure design.The effective width method that is widely applied in the analysis of isotropic planar stringer-stiffened panels has been extended to handle curved composite structures. The non-linear finite element analysis model of the stiffened composite plates was established with ABAQUS / CAE. The study of composite stiffened panels in compression buckling, shear buckling, and combined compression and shear buckling behavior was carried out, and predicted the more accurate buckling load and post-buckling carrying capacity. To validate this code, predictions obtained by this study were compared with experimental results and with ABAQUS calculations as well. Good agreement between the present proposed method, experiments and ABAQUS was found. Then, in the original state without damage, the impacts of parameters of the ribs height, thickness, and interfacial strength on the buckling load and ultimate strength of stiffened composite plates are discussed using the RIKS method. Finally, on the basis of the previous study, the stiffened curved plate model with impact and crack damage are established, and the microcrack direction position and other parameters influencing the buckling and post-buckling are analyzed. Meanwhile, the influence of the equivalent damage reduction on the post-buckling of impact damage is performed.