Monotonic Loading Tests on Semi-Rigid End-Plate Connections with Welded I-Shaped Columns and Beams

8 specimens of beam-to-column bolted end-plate connections with various details and welded I-shaped section columns and beams were tested under monotonic loads. Based on the specification for the end-plate connection rotation proposed, the contribution of the panel zone and the gap between the end-plate and column flange to the joint rotation have been obtained. The influences of both flush and extended types, column stiffeners, end-plate rib stiffeners, bolt sizes and end-plate thicknesses etc on the joint behaviour have been compared. The test results indicate that all these connections tested are typically semi-rigid. For the flush and extended end-plate connection, the joint rotation mainly derives from the relative deformation between the end plate and the column flange and the shearing deformation of the panel zone respectively. Using a special method to measure bolt strain, the bolt tension forces and their development and distribution have been depicted and studied, and two bolt tension force distribution models for end-plate connections using pretensioned bolts are recommended.