High Strength Steel in Buildings and Civil Engineering Structures: Design of Connections

There is an increasing demand for high strength steel in the construction of buildings and civil engineering structures. However, there is a significant lack of knowledge of the behaviour of this type of construction. Research must focuses on the characterization of the strength and ductility of members (tension, compression and flexural members) and joints. In view of the severe deformation demands that are placed on many type of joints, particularly bolted connections, a special emphasis is given to assess current joint design criteria to understand what is expected of the high strength steel material. To address these topics, an experimental investigation was undertaken on moment connections with end plates made from high strength steel S460, S690 and S960 (yield stress of 460 N/mm², 690 N/mm² and 960 N/mm², respectively) to provide insight into the nonlinear behaviour of this joint type. Test results show that the extrapolation of current design philosophy based on the semi-continuous/partially-restrained concept gives accurate strength predictions and that these connections can achieve reasonable rotation demands.