Mechanical performance of GFRP-profiled steel sheeting composite sandwich beams in four-point bending

This study proposed a novel GFRP-profiled steel sheeting composite sandwich beam (GPSS beam) composed of glass fiber reinforced polymer (GFRP) skins, a lightweight polyurethane (PU) foam core and a 0.9-mm-thick profiled steel sheeting. The interaction between the GFRP skins and the profiled steel sheeting was enhanced by the use of stainless steel core rivets. The flexural performance of the GPSS beams was studied through experimental and analytical methods. Eight beam specimens, including a control specimen, were tested in 4-point bending tests to verify the efficiency of the profiled steel sheeting to improve the stiffness, ultimate load-bearing capacity and energy dissipation capacity of the beams. Test results demonstrated that the bending stiffness and ultimate load-bearing capacity can increase up to 306% and 158%, respectively compared to those of the control specimen. The energy dissipation ability of GPSS beams was increased greatly by using stainless steel core rivets. Additionally, unlike the control specimen, the GPSS beams collapsed in a ductile manner. Analytical formulas for predicting the bending stiffness and ultimate load-bearing capacity of GPSS beams were proposed and captured these effects reasonably accurately. The flexural stiffness of the GPSS beams with the profiled steel sheeting were equivalent to those of the same size RC beams with a moderate to heavy reinforcement ratio of 1.0-2.4%, but the GPSS beams were 25.5-65.1% higher in ultimate load-bearing capacity and 5-8 times lighter in weight.