Isogeometric buckling analysis of composite variable-stiffness panels

Variable-stiffness panel with curvilinear fibers is a promising structural concept compared to constant-stiffness designs. However, for the traditional finite element analysis (FEA), there is no guarantee that the fiber angle is continuous and smooth due to element discretization. In this study, on the basis of Mindlin plate theory, the buckling behavior of composite variable-stiffness panels is investigated based on isogeometric analysis (IGA), whose main feature is that the continuity of fiber angle on the whole panel is guaranteed. In particular, since geometric stiffness matrix has a significant influence on the buckling behavior, it is obtained by performing a static analysis prior to the buckling analysis herein, which can further improve the prediction accuracy of current methods. Different fiber path functions, ply number, geometric parameter, as well as various boundary and loading conditions are adopted to verify the proposed buckling analysis method. Finally, the prediction accuracy, total degree-of-freedom and CPU time are compared with the traditional FEA, which indicates that the isogeometric buckling analysis method can provide an adequate accuracy in a more efficient manner.