Geometrically nonlinear analysis of composite stiffened plates using finite elements

Composite stiffened plates have been analysed for large deflection using the finite element method. An eight noded isoparametric laminated stiffened plate bending element developed earlier has been used. The element has the capability of including transverse shear deformation for the plate and the stiffener and incorporating one or more stiffeners anywhere within the element. The finite element analysis has been made using Mindlin's formulation and with the assumption of small rotation. The nonlinear equilibrium equations are solved by the Newton-Raphson iteration procedure. Plates and stiffened plates of isotropic and anisotropic material with different boundary conditions have been analysed and results have been compared with those available. Parametric studies have also been carried out.