Local joint flexibility of tubular K-joints reinforced with external plates under IPB loads

Abstract

In the present paper, the Local Joint Flexibility (LJF) of tubular K-joints reinforced with external plates is investigated. For this purpose, in the first step, a finite element (FE) model was generated and verified with the results of several available experimental tests and equations. In the next step, a set number of 450 FE analysis on the 150 FE models were conducted to investigate the effect of the plate size (η and λ), the joint geometry (γ, τ, ξ, and β), the angle between brace and chord (θ), and the loading conditions on the fLJF and the fLJF ratios (ψ). In the FE models, the welds were generated to join the braces to the chord. The results showed that the fLJF of the reinforced K-joints is remarkably smaller than the corresponding un-reinforced joints. Despite the considerable effect of the plates on the fLJF in K-joints under IPB moments, there is no study or formula on any reinforced K-joints. Consequently, the results were utilized to propose two design formulas for determining the fLJF in K-joints reinforced with plates under different IPB moments.