Analysis of stiffened rectangular plate

Abstract

Observations of structures created by nature indicate that in most cases strength and rigidity depend not only on the material but also upon its form. This fact was probably noticed long ago by some shrewd observers and resulted in the creation of artificial structural elements having high bearing capacity mainly due to their form such as girders, arches and shells. Adding stiffeners to the plate complicates the analysis and several assumptions must be made in order to facilitate a solution to the problem. In the present study, a simulation model for large deflection static analysis of a thin rectangular stiffened plate under transverse loading has been presented. The mathematical formulation is based on variational form of energy principle, where the displacement fields are assumed as finite linear combination of admissible orthogonal functions, satisfying the corresponding flexural and membrane boundary conditions of the plate. Geometric nonlinearity has been incorporated through consideration of nonlinear strain-displacement relationship. The resulting nonlinear set of governing equations is solved through a numerical procedure involving direct substitution method using relaxation parameter. Entire computational work is carried out in a normalized square domain, which is divided into subdomains depending on the number, orientation and location of the stiffeners. The domain decomposition technique is specially developed to introduce adequate number of computation points around the location of stiffeners and boundaries of the plate. Validation of the present method and solution technique has been carried out successfully with available results. Various results are presented using different types of stiffeners attached to plate. Different results have also been furnished for variation of stiffener location.