Postbuckling and Failure Analysis of Axially Compressed Composite Panels Using FEM
Stevan Maksimović
In order to improve confidence in composite structure design, a better description of the failure of laminates is necessary. In this paper the buckling and postbuckling behaviour of axially compressed layered composite panels is studied by means of Finite Element Method (FEM). A series of experiments was conducted to verify the FEA-results, but also to address the stability and strength of the composite structure. Combining a geometric nonlinear finite element analysis (FEA) based on the von Karman theory and High Order Shear Deformation Theory (HOST) are used to study the first-ply failure behavior as well as the postbuckling behavior of laminated type composite structures. For this purpose and for the investigation of the failure responses, the improved 4-node layered shell finite elements are used. The finite element formulation is based on the third order shear deformation theory with four-node shell finite elements having eight degrees of freedom per node. A simple method is proposed to predict buckling loads and the post-buckling behaviour. The comparisons between the numerical and the experimental results show quite a good agreement.
Key words: composite materials, panel, fracture mechanics, stability analysis, initial failure analysis, Finite Element Analysis (FEA).