Experimental and nonlinear analytical of the flexural performance of timber-filled steel tubular composite beams

Steel-timber composite structures present excellent and stable engineering performance. This study presents a novel timber-filled steel tubular composite beam consisting of cold-formed thin-walled rectangular steel and timber.Eleven timber-filled steel tubular composite beams were prepared with various section parameters. A four-point bending test was conducted to evaluate the flexural behaviour of the beams. The failure mode, deflection deformation, and load-carrying capacity were analysed based on the test phenomena and data; the influences of the various parameters on the flexural behaviour were explored.Finally, a simplified mechanical model for flexural bearing capacity was established based on the assumption of plane section and the ideal elastic-plastic.The results show that compared to the timber-filled steel tubular composite beams with composite connection combined the shear screw and the epoxy resin viscose, the beam with a simple epoxy resin adhesive connection has high bearing capacity and deformation performance. The screws have little effect on the bearing capacity and bending stiffness of the composite beam, but can effectively improve the residual bearing capacity of the beam.