Flexural performance of steel fiber reinforced concrete filled stainless steel tubular trusses

The stainless steel tubular truss is known for dealing with corrosion problem of tubular truss, and mechanical properties of tubular truss can be improved ulteriorly by filling concrete to effectively avoid local buckling of steel tubular. To study the influence of the filling position of steel fiber reinforced concrete (SFRC) on flexural behavior of stainless steel tubular truss, four-point bending tests were carried out on four specimens. The specimens consist of three SFRC-filled stainless steel tubular trusses and a hollow section stainless steel tubular truss as control group. The experimental results show that filling the chord with SFRC can significantly improve the bearing capacity of the stainless steel tubular truss. At the same time, the internal mechanism of SFRC improving the bearing capacity of the structure is analyzed from the perspectives of failure mode, overall deformation characteristics and strain development of material. The effects of several different SFRC filling methods on improving the mechanical performance of specimens were compared. Finally, the finite element method is used to analyze the tested specimens. The accuracy of the proposed finite element modeling is proved, and the optimal filling method to make full use of the material property of SFRC is obtained through stress analysis.