Bending analysis of stiffened laminated plates

Stiffeners are commonly attached to composite laminates to achieve higher stiffness/weight and strength/weight ratios. A layer-wise finite element formulation is developed for the bending analysis of stiffened laminated plates. The laminated plate is discretized into layers in the thickness direction and then the degenerated shell elements are employed to model each layer. The stiffener is modeled using a general 3-D beam element. Interlayer continuity relations are established for all the layers in the thickness direction. The primary advantage of the proposed finite element model lies in its application to both thin and thick laminated plates. Extensive numerical examples are presented for non-stiffened isotropic plates, non-stiffened laminates, stiffened isotropic and laminated plates. Parametric studies are conducted with different aspect ratios, plate width to thickness ratios, ply orientations, and number of layers. The results agree well with the ones reported in the literature.