Ductility of the double-sided bolted steel end-plate joint with column web openings under column loss scenario

Abstract

The load capacity and the rotational stiffness of the joints are the main parameters required in the design of steel-framed structures in a persistent design situation. In an accidental situation, high ductility of the joints is required to create and develop catenary action under the column loss scenario. Numerical parametric analyses of double-sided bolted steel end-plate joints were performed, focusing on the increase in the ductility of the joints by applying openings to the web of the column. The circular and longitudinal shapes of the openings were applied in two- and multi-configuration arrangements. Advanced 3D FEM models of the steel substructure were created using Abaqus software and validated versus the own experimental tests. The results demonstrate that application of column web openings in most cases allowed for a significant increase in ductility, which for steel joints means rotation capacity. In flush end-plate joints, an increase in ductility of joints was obtained in the range of 2–72 %. In extended end-plate joints, ductility improved in the 4–50 % range. An increase in the load capacity of the joints was obtained mainly in the case of extended end-plate joints, where a maximum improvement of 20 % was reached. The openings in the column web also change the failure mode of the joint, allowing the avoidance of premature destruction of the bolts. Some practical recommendations for choosing column openings in the design process are also presented.