Edinburgh Napier University

  In current design practice, analysis of plate and grid structures in civil engineering, such as waffle slabs, ribbed plates and slab-girder bridges, is based largely on code-specified approximate methods, and deflections of these systems are rarely evaluated owing to the complexity of calculations. A semi-analytical method is presented for bending and deflection analyses of plate and grid structures subjected to vertical loads. The proposed approach is derived based on the finite element method and can be used to solve conveniently and effectively the problem of the stiffened plates with irregular shape and openings, in which far fewer unknown variables will be involved in comparison with the finite-element method and less computation time will be required by employing the analytical transformations instead of the traditional matrix inverse. It was shown from the numerical investigations that the proposed method provided an efficient, yet accurate, means of analysing the stiffened plates. The results of the proposed approach for the example structures show good agreement with those from the finite-element method and experiments.