LAUSR

Abstract Tube–gusset plate joints with multiple ring stiffeners are commonly used in steel tube towers. The load on the gusset plate can be distributed to each stiffener according to its Tension and Compression (T&C) stiffness. The ultimate state of joints with multi-stiffener plates can be equivalent to that of the stiffener plate. In this study, an experimental investigation and theoretical analysis of the failure mode and T&C stiffness of ring stiffener under symmetrical loading were performed. The experimental programme included material tests and 10 groups of static loading tests of the ring stiffener plates. Then, finite-element models were developed and validated against the test results. The validated numerical models were utilised to perform numerical investigations of 280 different single-ring stiffener plate specimens with D/ t = 32 .3–55.9 and R/ t r = 6–33.3. Using the experimental and numerical results, the parameters affecting the T&C stiffness of the ring stiffener plates were identified. According to the deformation characteristics of the ring stiffener plates, a T-shaped ring beam calculation model was established, along with the corresponding calculation formula. Calculation results based on the formula were compared with the numerical analysis results, and the results indicated that the theoretical model can accurately calculate the T&C stiffness of the ring stiffener plate. Thus, the proposed calculation method for the T&C stiffness of a ring stiffener can be used to guide the design of joints in actual engineering projects.