J. Buick Davison

Strength and rotational stiffness of simple connections to tubular columns using flowdrill connectors

Abstract A new thermal drilling technique (the flowdrill process) has made it possible to use ordinary bolts in tapped holes in relatively thin-walled tubes. This in turn has opened the opportunity for traditional partial depth and flush endplate connections to be used to join open section beams to tubular columns in simply designed braced steel frames. The experimental work reported concerns a series of tests conducted to investigate the moment capacity and rotational stiffness of simple joints bolted to tubular columns using flowdrill connectors. Tests show the connections to behave in a manner suitable for use as either pinned or partial strength connections for simply designed braced steel frames. This paper is one of a series; the others deal with moment-resisting connections and the influence of filling the tubes with concrete.

Moment-capacity and rotational stiffness of endplate connections to concrete-filled tubular columns with flowdrilled connectors

A test programme to obtain experimental data on the behaviour of endplate beam to column connections has been conducted. The reported tests concern joints made between universal beams and tubular columns using endplates bolted directly to the column face with ordinary bolts screwed into threaded holes formed using the flowdrill process. Results obtained from tests are presented in a series of three papers; this final paper reports tests conducted with concrete-filled tubes and the results are compared with those from a parallel series of tests in which the tubes were unfilled. Significant differences in strength and stiffness were observed.

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

Abstract 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 be used to secure endplate beam connections to tubular columns. A series of tests was conducted to investigate the strength and rotational stiffness characteristics of joints made in this way. The results of the tests described 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 ductility but the joints have relatively low stiffness for a nominally rigid joint. Connections of this type are ideally suited for use in semi-rigid design methods.