ABSTRACT
This paper provides a review of the continuing development of finite element formulations for the geometrically non-linear analyses of stiffened laminated and sandwich structures to solve a variety of problems including static, stability and dynamic analyses. The effects of geometrical non-linearity, and specific difficulties encountered in non-linear analysis of stiffened structures are presented and discussed. The approaches and idealizations for modelling stiffened structures with the most commonly used methods of solution are reviewed. A finite element formulation is proposed to efficiently model stiffened and un-stiffened laminated and sandwich plates with arbitrarily orientated laminated stiffeners in geometrically non-linear situations. The formulation, which is based on von Kármán’s large deflection plate theory, combines an eight-noded isoparametric quadratic element for the plate and a three-noded curved beam element for the stiffeners by using the concept of equal displacements at the plate-stiffener interface. A variety of stiffener shapes and sizes can be included with the proposed analyses. An iterative solution technique is adopted to solve the non-linear equations. Benchmark examples from the open literature are considered for the validation of the proposed formulation in the linear and non-linear range.
