Numerical studies on steel-UHPC-steel sandwich beams with novel enhanced C-channels

Abstract

Firstly, this study developed a new type of sandwich composite beam using ultra-high performance concrete (UHPC) and novel enhanced C-channels (ECs). Then, this study developed a nonlinear finite element model (NFEM) for steel-UHPC-steel sandwich beams with ECs (SUSSB-ECs) using general software package ABAQUS. The developed NFEM detailed simulated the novel sandwich composite beams including the complex geometry of ECs, the complex interactions between the ECs and UHPC core, and nonlinearmechanical properties of UHPC and steel. The comparisons of NFEM simulation results with eight four-point bending tests indicated that the NFEM simulated well the ultimate strength behaviour of SUSSB-ECs in terms of load versus strain/deflection curves, deformations and cracks in UHPC, and stiffness/strength indexes. Parametric studies were then performed with the developed NFEM to study the key parameters influencing the ultimate strength behaviour of SUSSB-ECs. The parametric studies showed that increasing the thickness of tension and compression steel faceplates had significant influences, but the spacing of ECs had marginal influences on ultimate strength behaviours of SUSSB-ECs. Reducing the shear span ratio did not change the flexural failure, but reduced the flexural bending resistance of SUSSB-ECs. Increasing the grades of steel faceplates had ignorable influences on the stiffness, but significantly increased the bending resistance of SUSSB-ECs.