Static and dynamic behaviour of non-composite steel-concrete-steel protective panels under large deformation
Steel-concrete-steel (SCS) panels are an effective means for protecting critical infrastructure facilities from the effects of external detonations. Existing designs of SCS panels utilise composite action between the core concrete and the external steel plates which requires mechanical or adhesive connections. This paper presents an experimental programme of research in which the steel skin does not act compositely with the concrete core. High effectiveness in resisting blast and impact loads is achieved through special detailing of the flared end connections that provide axial fixity as well as restraining the relative movement between the concrete core and the external steel plates. From the experimental results it was observed that the failure mode of simply supported non-composite SCS panels was related to failure of the weld connecting the end plate and the faceplates due to shear loads induced by restraint effect. The SCS panels with axial restraints were able to undergo large deformation without weld fracture and to develop the tensile membrane action. The tensile membrane action was observed in all tested panels at large deformation. SCS panels utilising stainless steel skin showed the highest transverse load resistance. The experimental results proved that the axial fixity of the panels enables tension forces to be generated in the load-carrying mechanism under increasing lateral deflections. It has been shown that non-composite SCS panels with axial restraints can provide very significant resistance to the transverse loads through large deformations with the end rotations of up to 20 degrees. This makes non-composite SCS panels with the axially restrained connections a good candidate for designing high-performance protective barrier structures to resist extreme impact and blast loads.