Simplified thick plate analogy for the analysis of all-steel sandwich panels

An all-steel sandwich panel consists of two steel facing flat plates spot-welded onto a core of stiffeners, which may consist of zed sections, tophats, channels or corrugated sheeting.Such panels have been studied extensively, and both numerical and analytical comparisons have been reported. This paper presents a modified thick plate approach for the analysis of sandwich panels. To better appreciate the development of the proposed method, a brief review of the previous modelling techniques-i.e. closed-form solution, grillage analogy and the conventional finite element modelling-is given. At the present time, the closed-form solution is not amenable to analysis of panels with penetration or support conditions other than simply-supported all round. Response predictions using the grillage analogy necessitates a regular grid, and, for a panel with small penetration, a very fine grid is required. The advanced finite element package is ideal as a research tool but it requires significant computing time and memory. The proposed modified thick plate analysis reported here obviates the difficulties mentioned above. In this technique,it is assumed that the three layers of steel plates i.e. the top and bottom facing plates and the core, may be 'compacted' into an equivalent single layer of characteristics of the sandwich panel are preserved. Comparisons of deflections are presented for the different methods. Available experimental data are also provided to verify the proposed technique.