Static capacity of tubular X-joints reinforced with fiber reinforced polymer subjected to compressive load

Abstract

In the present paper, the initial stiffness, the ultimate capacity, the capacity ratio, and the failure mechanisms of the tubular X-joints reinforced with Fiber Reinforced Polymer (FRP) under compressive load are investigated. For these aims, a finite element (FE) model was generated and verified with the available experimental data. Afterward, 109 finite element (FE) models were created to investigate the efficacy of the FRP layers (length, number, and orientation) and the connection geometry (β, τ, and γ) on the static performance of the reinforced X-joints. In the FE models, the effects of the weld profile and the contact between the FRP and the members (chord, weld, and braces) were considered. Results showed that the FRP can remarkably enhance the stiffness, ultimate capacity, and improve failure mechanisms. Despite the notable effect of the FRP on the performance of the joints, there is not any study on the X-joints with FRP. Hence, after the parametric study, the FE results were used to propose a theoretical formula, based on the yield body model, to predict the ultimate strength of X-joints with FRP. In addition, the proposed formula is confirmed by the acceptance criteria of the UK Department of Energy.