Analysis of Extended Hollo-Bolt connections: Combined failure in tension

This paper investigates the combined failure mode of the Extended Hollo-Bolt (EHB) and the effect of the column thickness on the tensile behaviour of the blind fastener. A three-dimensional Finite Element (FE) model was developed, validated against experimental data and used in a parametric study. The non-linear numerical model, which simulates a single row of two EHB in tension, presents reliable results of the column and bolt failure modes in agreement with experimental data. It is concluded that the failure mode is first controlled by the plastic resistance of the component limited by concrete crushing accompained with hollow section yielding; it is then controlled by the strength of the bolt. An analytical model which predicts the global force-displacement relationships when varying the column thickness is proposed. Therefore, the stiffness and the strength behaviours of this combined mode of failure for the studied blind fastener can be estimated.