Bending performance of an innovative CHS T-joint connecting with ring plates in narrow-based towers

Abstract

The paper introduced an innovative CHS T-joint connecting with ring plates (i.e., CHS-TR) and focused on its bending performance. To analyze the failure mode and bearing capacity, six groups of specimens were designed for testing, including three free extended widths of ring plate and two specifications of brace. Subsequently, the finite element model was established and verified to further analyze the deformation characteristics of the chord and ring plate. Additionally, the influence of diameter-to-thickness of brace γ_b, diameter-to-thickness of chord γ_c, diameter ratio of brace and chord φ, width-to-thickness of ring plate n, axial compression ratio β on the bearing capacity of CHS-TR was further revealed. The research results indicate that CHS-TR exhibits excellent bending performance. The ring plate not only plays a role in force transmission, but also enhances the constraint on the chord. Specifically, the ring plate has a significant effect in the transition regions of −30 °∼-90 ° and 30 °∼90 °. The bearing capacity of CHS-TR is closely related to two failure modes. On the one hand, when both the chord and the ring plate fail, the bearing capacity decreases with the increase of γ_c and β, and increases with the increase of n, regardless of γ_b and φ. On the other hand, if local buckling occurs on the compressive side of the brace, the bearing capacity is inversely proportional to γ_b and directly proportional to φ. Finally, a bearing capacity calculation method of CHS-TR was proposed based on the code.