Degree of bending in X-connections retrofitted with different types of fiber-reinforced polymers subjected to axial load
Hossein Nassiraei, Behrouz Asgarian, Pooya Rezadoost
Abstract
In marine engineering, specifically regarding offshore jacket constructions, the stress experienced by tubular connections' chord thickness emerges from both bending and membrane stresses. The Degree of Bending, defined as the ratio of bending stress to total stress, is important in evaluating the fatigue resistance of these structural joints . This study delves into the Degree of Bending of tubular X-joints with diverse fiber-reinforced polymers (FRPs) under axial load . 116 FE simulations were created to evaluate the impacts of FRP attributes (like the type of material, the number of layers, and the orientation) alongside the joints’ non-dimensional geometric parameters on the Degree of Bending. In the FE models , the Solid, Shell, and Contact elements were used for modeling the joints. The outcomes suggest a marked reduction in both membrane and bending stresses due to FRP application . Furthermore, elevations in both the Longitudinal Young’s modulus of FRP and the quantity of FRP sheets notably enhance fatigue resistance. The findings reveal that the stress intensity factor is decreased by 83.9 % compared to the equivalent un-enhanced connection. Finally, following the detailed parametric study , a novel equation is proposed to accurately estimate the Degree of Bending for such scenarios.