Applications of Sandwich Plate System for Ship Structures 1 KVRamakrishnan
Sandwich Plate System (SPS) is an alternative to conventional stiffened plate construction. Sandwich plate system is a lightweight material that consists of two metal plates separated by a core. Plates, usually made of steel, are joined via perimeter bars on the edges of the plate. Polyurethane elastomer core transfers shear and bending forces between plates and dissipates strain energy over a large area, reducing load concentrations and the possibility for permanent deformations. Sandwich plate system eliminates the need for secondary stiffeners, making the structure less complex and flush. Considering the high strength to weight ratio, ease of construction, blast and ballistic properties of the material, availability of a flush surface etc. SPS has been widely used in building bridges, stadiums, floors, blast walls etc. SPS panels have also been used in ship repair as an overlay on existing structures, converting them conventional steel to sandwich plates. The concept of complete hull structure made of SPS is a big challenge. At present, no thorough study over complete ship bull sandwich structure is available, mainly due to the non availability of design tools for the SPS concept. However, the introduction of Class rules has brought in the use of sandwich structures in marine construction. It is roughly estimated that weight reduction possibilities of SPS over the conventional structure varies from 10 to 70% In this paper, the advantages of SPS are examined. The scope for SPS panels in shipbuilding, and various areas where further research and progress could be made is also recommended.