Development of Composite Sandwich Structures for Arctic Region

Abstract

A cone-shaped steel-concrete composite structure has been proposed for Arctic offshore structures. This type of cone structure is able to withstand the ice forces imposed thereon by impinging ice sheets and other larger masses of ice wherein the structure has an upper conical portion coaxially positioned relative to a lower cylindrical portion. This study explores the use of curved steel concrete- steel (SCS) sandwich system in the proposed arctic cone structure. SCS sandwich system, which combines the beneficial effects of steel and concrete materials, has shown promising benefits over conventional plates and stiffeners design and heavily reinforced concrete design because of their high strength to weight ratio. Shear connectors has been proposed to connect steel face plates and cementitious core material. The proposed SCS sandwich system can reduce structural complexity in particularly the number of weld joints which are prone to fatigue and corrosion, hence increase service life, cut down the cost of fabrication, and reduce the manpower cost to operate, inspect and maintain the structure in the long run. Considering local ice load, the punching shear strength of the SCS sandwich composite shell was studied experimentally. The SCS specimens were designed using the ISO ice pressure. The experimental results show that they possess far higher resistance against patch load caused by ice. Moreover, the load-deflection behavior of the curved SCS sandwich system is ductile and it can absorb a great deal of energy at failure.