Investigating the T-stub connection with different web-to-flange joint configurations

Abstract

This article evaluates the impact of different web-to-flange joints in the T-stub connection. Mechanical properties of T-stub components were evaluated by experimental tests and by finite element simulations. Three different web-to-flange junctions are evaluated: laminated components, fillet welding and full penetration welding. Generally, laminated and fillet welded T-stub profiles have been considered in the past to study the behavior of the tension zone in the end plate connections. However, in structures predominately subjected to low and high cycle dynamic loads, and susceptible to a fatigue crack, is mandatory full penetration welds execution. This article evaluates the influence of full penetrated welding in the behavior of the full component, and not only in the mechanical capacity of the weld and the weld area. This article analyses how the increment of the free span between the bolt position and the web modifies the position of plastic hinges in the vicinity of the web, with the consequent reduction of strength and stiffness. A total of 72 experimental samples with 8 different geometries were tested to evaluate the different behavior of the web-to-flange joint configuration. A detailed finite element model of the T-stub component has been developed for each joint configuration. The model has been calibrated with experimental results, and it is able to accurately capture the full range behavior of the T-stub featuring any failure model. From the results of the experimental tests and their validation by finite element analysis, it can be concluded that the welded T-stub connection has a lower mechanical resistance, with no significant differences between fillet welding and full penetration welding. And the effect of the type of welding is only seen in ductility, and not in resistance or stiffness. On average, the typologies with full penetration welding have a maximum displacement 1.43 times higher than the fillet welded one.