ABSTRACT
Steel-concrete composite structure fully utilizes the high tensile strength of steel and high compressive strength of concrete (Wang 2008). Sause of Lehigh University firstly put forward the concept of tubular flange composite girder which changes the steel flange into the concrete-filled tubular flange (Sause 2003, Dong 2009). Kim studied the application of concrete-filled tubular flange composite girder in straight bridge (Kim 2008); Wang studied the mechanical performance of concrete-filled tubular flange composite girder (Wang 2011). Under the premise of the same steel amount, concrete-filled tubular flange composite girder has characteristics of higher strength, stiffness and stability than I steel girder. But the construction technology is complicated, and the reliability of longitudinal connection is insufficient.
Referring to the previous study of tubular flange composite girder, try to replace the concrete with the internal stiffener and external stiffener. Hollow tubular flange composite girder with concrete top plate has small dead load, convenient construction. Using internal stiffener, external stiffener and transverse stiffeners to prevents overall bulking and local bulking. In order to know the strength, stiffness and stability of hollow tubular flange composite girder, study the mechanical behavior of hollow tubular flange composite girder is necessary.
In this paper, the research on the bending behavior of innovative hollow tubular flange composite girder was carried out. Through analyzing bending behavior test results and the failure model of both circular and rectangular hollow tubular flange composite girder, the mechanical behavior was known; Then the finite element analysis (FEA) software ANSYS was used to simulate the bending behavior of test girder considering material nonlinearity. After checked by the test results, FEA was conducted to simulate the bending behavior of hollow tubular flange composite girder with different design parameters, such as material property, cross section dimension and so on. Based on theory analysis, calculation formula of ultimate bending capacity was proposed based on simplified plastic theory.
