Experimental and numerical investigation of T-stub plastic resistance

In structural robustness studies, column loss scenarios may be considered. Such scenarios require the structure to be calculated in its deformed configuration if a ductile response of the structure can be ensured. In case of such scenario, joint response plays a crucial role. However, nowadays, the component method for characterising joints has been essentially developed to predict (i) the elastic stiffness and (ii) the plastic resistance; in terms of ductility, only general recommendations to guarantee a sufficient ductility to perform a plastic analysis are provided. So, researches are currently being carried out on components to extend this method to predict their behaviour up to failure. However, it appears that some components such as the t-stub are still not fully mastered even in the elastic domain and their plastic resistance appears as significantly underestimated.

This article addresses the problem of predicting the plastic resistance of short unstiffened T-stubs under monotonic loading. First, a review of the current analytical models is proposed. The accuracy of these models is compared against experimental results available in the literature. Through first comparisons, it appears that assumptions made in the Eurocode mode 1 model are too conservative, leading to a significant underestimation of the plastic resistance. Therefore, a numerical model using Abaqus© is validated against the experimental tests and uses to perform a parametric analysis Allowing to realise a critical assessment of the Eurocode model assumptions.