Strength and rotational response of moment connections to tubular columns using flowdrill connectors

Using the flowdrill process it is possible to form threaded holes in steel tubes even with wall thicknesses less than 12 mm. Ordinary bolts may then b e used to secure endplate beam connections to tubular columns. A series of tests was conducted to investigate the strength and rotational stiffness ch aracteristics of joints made in this way. The results of the tests describe d on both thick flush endplates and extended endplates show that strengths approaching the plastic capacity of the supported beam and large rotational capacities can be obtained. Deformation of the tube face gives excellent d uctility but the joints have relatively low stiffness for a nominally rigid joint. Connections of this type are ideally suited for use in semi-rigid d esign methods. (C) 1999 Elsevier Science Ltd. All rights reserved.