LAUSR

Abstract This paper aims to investigate the local joint flexibility (LJF) of tubular X-joints with collar plates subjected to axial load. A total number of 136 FE models were generated and analyzed to investigate the effect of collar plate size and joint geometry (η, τc, β, γ, and τ) on the local joint flexibility factor (fLJF). Also, the weld profiles and the contact between the chord wall and the collar plates were modeled in the numerical simulations. Results showed that the increase of the collar plate thickness and length results in the decrease of the fLJF. Despite the difference between the fLJF of unreinforced and collar plate reinforced X-joints, there has not been any study on the fLJF of the X-joints reinforced with collar plate. Also, there is no design equation for determining the fLJF of the collar plate reinforced X-joints. Thus, the results of the parametric study were used to develop a design formula, to determine the fLJF of X-joints reinforced with collar plates under axial load.