Numerical analysis of the axial strength of CHS T-joints reinforced with external stiffeners

• A reinforcement method which uses external stiffeners welded to the CHS T-joint is investigated.
• A finite element model by shell element is established to compute the ultimate axial capacity of unreinforced and reinforced CHS T-joints with the external stiffeners and the model is verified by experiment.
• A numerical parametric study is performed to evaluate the reinforcement effect of the external stiffeners on the ultimate strength of CHS T-joints.

This study reinforced circular hollow section (CHS) T-joints with external stiffeners and analyzed the axial strength of both the unreinforced and reinforced T-joints. The SHELL181 element in ANSYS was used to establish FE models of the T-joints. A comparison between the experimental results indicated that the numerical method could be used to compute the strength for the unreinforced and reinforced CHS T-joints. To further investigate the reinforcement effect of the external stiffeners, a numerical parametric study was conducted. The study then evaluated the variations in strength of differently sized stiffeners. It was found that the joint strength increased significantly as the size of the stiffener increased. The reinforcement effect is more dependent on the stiffener length than on the stiffener height, but it is reasonable to adopt stiffeners with equal lengths and heights since this shape is commonly-used in engineering projects.