Finite element analysis of bolted T-stubs undergoing large displacement: A preliminary study

Background: In recent years, there have been increased interests by the steel structures community to characterise the large-deformation response of T-stubs to evaluate the deformation capacity of bolted joints. However, little information exists on the influence of second-order effects on the response of bolted T-stubs and, consequently, there are no existing guidelines on how to include these effects in design. Objective: In this paper, we assess the influence of second-order effects in T-stubs bolted to a rigid support through a parametric investigation, using finite element analysis. Methods: Both material and geometrical non-linearities were considered since they are known to have a critical impact upon the performance of T-stubs. A benchmark model is first generated and validated and then used to carry out a parametric investigation. A method to assess the contributions of membrane forces to the overall deformation response of a T-stub is also proposed based on the introduction of a non-dimensional parameter Ψ. Results: The combination of geometric parameters that are most affected by second order effects, induced by large displacement, was identified. A direct correspondence was found between the extent of second order effects that has developed and the index Ψ: a higher index implies a greater influence by second order effects.