Postbuckling of laminated composite plates using NURBS-based isogeometric analysis

In this paper, postbuckling behavior of laminated composite plates is investigated using NURBS-based isogeometric analysis (IGA). A Green strain tensor with small rotations is proposed. Both von-Karman strain tensor and the proposed strain tensor are formulated. Governing equations are derived in the framework of first-order shear deformation theory (FSDT). Finite elements based on NUBRS show the robustness in performing a laminate with intentional imperfections as well as deformed mode shapes. Quadratic NURBS elements (Q9Nurbs) are used to construct physical meshes in C1 continuity. Newton-Raphson scheme is adjusted to geometric imperfections and employed for non-linear analysis procedure. In numerical examples, the postbuckling paths of laminated composite plates in sense of von-Karman strain theory and the proposed strain theory are presented. The obtained results of isotropic, symmetric, antisymmetric angle-ply and cross-ply laminates are verified with those available in literature.