Static strength of collar plate reinforced tubular T/Y-joints subjected to tensile loading

So far, some methods to enhance the static capacity of steel tubular joints have been introduced. Most of these techniques can only be used for structures during the design (e.g. joint can, ring, rack/rib, and doubler plate), But there are only a few methods which can be used during both design and service (e.g. collar plate and FRP). These methods can be valuable methods for such rehabilitation purposes in old and new structures. An existing tubular joint can be reinforced by introducing plates to the outside of the chord resulting in what is called collar plate reinforced joint. In this study, a set of analyses was performed on 210 steel T- and Y-joint finite element (FE) models subjected to tensile brace loading. Also, failure mechanisms of the reinforced joints are investigated. Based on the results of collar plate reinforced T/Y-joints FE models which verified against experimental data provided by Choo et al. [3], a comprehensive ultimate strength database was prepared and finally through nonlinear regression analysis, a parametric equation was proposed.