Structural Behavior of Hybrid FRP-Concrete-Steel Double-Skin Tubular Columns

In this paper, a new hybrid FRP-concrete-steel double-skin tubular member recently proposed by the third author is discussed, with the emphasis being on its potential as key lateral and vertical load-resisting members in structures located in seismically active regions. In this new structural member, the three constituent materials are optimally combined: the outer tube is made of fibre-reinforced polymer (FRP), the inner tube is made of steel, and the space in-between is filled with concrete. While such a member may be used as a beam, its advantages are most obvious when used as a column so this new member may also be conveniently referred to as a hybrid FRP-concrete-steel double-skin tubular column (DSTC). A series of preliminary tests have recently been conducted, in which the concentric compressive behaviour and the flexural behaviour of the member were investigated. The test results showed that this new hybrid member exhibits good ductility and energy dissipation capacity