Edinburgh Napier University

  During the past three decades, a large amount of research results on the analysis and design of stiffened plates has been reported. Most of the methods used in the analyses include finite element [1,2,3], finite strip [4,5,6] and boundary element [7,8] analyses.
In this paper, an effective semi-analytical method is proposed based on the finite element approach to obtain an accurate analysis of stiffened plates. The proposed method can be used effectively and conveniently to solve the problem of a stiffened plate with irregular shape and openings, multi-connective-domain or discontinuous material property and arbitrary oriented stiffeners, but involving much less unknown variables as compared to the general finite element methods. Moreover, it has been shown that the proposed method has more flexible geometry adaptability than the finite strip method by utilising the naturally existed intrinsic relationship among the nodes on the same nodal line with one analytical expression.

The higher efficiency of the proposed method has been found on reducing the unknown variables as compared to the boundary element method. By employing the proposed analytical transformations instead of the traditional matrix inverse, a significant saving in computation time as compared to the static condensation method can be achieved.

Although the proposed approach is based on the finite element method, only a few modifications to the original FEM programming are needed when immigrating the FEM to proposed method. Furthermore, if the nodal line concept is extended to the boundary of an element, it is predicted that the proposed method can be used to develop super elements.

It has been shown in the numerical investigations that proposed method provides an efficient, yet accurate, means of analysing general stiffened plates. The predictions of the proposed analysis for the example structures show very good agreement with the finite element method and experiment results.