RESEARCH ON THE STATIC STRENGTH OF SQUARE TUBULAR T-JOINTS REINFORCED WITH COLLAR PLATE UNDER AXIAL COMPRESSION

The fundamental research work on the square tubular T-joints reinforced with collar plate is carried out incluing theoretical analysis, experimental tests and finite element simulation. Firstly, the equation for predicting the static strength of a collar plate reinforced square tubular T-joint under axial compression loading is deduced based on the yield line model. Thereafter, two collar plate reinforced square tubular T-joints and two corresponding unreinforced T-joints are analyzed through experimental tests and finite element simulation. It is found that the collar plate can improve the bearing capacity of the T-joints significantly. Additionally, a total of 18 square tubular T-joints are analyzed by using the finite element method. The results show that the static strength of collar plate reinforced T-joints, compared with the corresponding unreinforced T-joints, has a significant improvement, and the equation for predicting the static strength of a collar plate reinforced square tubular T-joint is reasonably accurate when the collar plate has enough stiffness and the failure mode is mainly local buckling.