Stability And Load-carrying Capacity Analysis Of Stiffened Composite Panels

At present, stiffened composite panels have been widely used in aviation and other fields. The stiffened structures are always subject to compression, shear loads and so on, which will make the stiffened structures instability. To satisfy the structural safety, stability analysis is often carried on the stiffened structures by engineers, this method is generally called buckling analysis, which is gotten from the results of buckling mode and buckling load. After buckling, the structures have a higher strength capacity, which is called post-buckling behavior. The post-buckling failure mode and failure load are gotten from post-buckling analysis of structures.Buckling and post-buckling analysis of stiffened composite panels is complied on the flat of ABAQUS in this paper, the numerical models are I-section and hat section stiffened composite panels. In order to investigate the buckling mode, buckling load and failure mode of structure, stiffened composite panels which are subject to compression, shear and combination of them are used to analyze buckling and post-buckling behaviors. The structures are composed of skins and stiffeners, with the adhesive between the skin and stiffeners. Skins and stiffeners are considered by composite laminates and cohesive elements between skins and stiffeners are added. Quads failure criteria and Hashin's failure criteria are adopted to identify the buckling and post-buckling behaviors. Also, the buckling loads and post-buckling strength capacity of stiffened composite panels are well predicted to meet the experiment results. Numerical results show that the model is effective. Parametric studies are conducted to find the effects of geometric parameters of stiffeners, such as height and thickness of stiffeners and stiffener numbers on buckling loads and ultimate strength of stiffened composite panels. The results indicate that the buckling load and ultimate strength improved by the increased height, thickness and number of stiffeners, also, the process of adhesive is observed, and finally optimal models are selected. Numerical examples demonstrate the effectiveness of the proposed model and boundary conditions. In this regard, some useful conclusions are given to analyze composite structures.