Ultimate Performance of External End-plate Bolted Joints Under Column Loss Scenario Accounting for the Influence of the Transverse Beam

Steel beam-to-column joints are generally designed and analysed considering the response parame-ters in their main bending plane, disregarding the influence of the connections and the related beams in the transverse direction. However, the 3D response of the joint can be influenced by the presence of the transverse beams in the case of column loss scenario.

The objective of the study is to investigate the influence both the influence of the transverse beams and the potential effectiveness of the design rules developed within the research project EQUALJOINTS in case of column loss scenarios.

A comprehensive set of parametric finite element analyses was carried out. Three external joints were selected, and two types of column loss scenarios were investigated for 2D and 3D joint configurations.

The obtained results show that the presence of the secondary beams is beneficial to arrest the progressive collapse since it increases the resistance of the joint assembly, reducing the plastic demand into the primary moment-resisting joint.

The presence of the secondary beams improves the joint performance under column loss thanks to their torsional stiffness; when the dimensions of the double cleat connection are comparable with those of the primary moment resisting joint, they are also able to increase the stiffness of the entire joint.

Severe plastic deformation can be observed in the double cleat connections in joints directly affected by the column loss. Therefore, these connections should be properly designed in order to guarantee adequate ductility.