ABSTRACT
This paper presents the results of an experimental and analytical investigation into the structural behaviour of an innovative moment-resisting connection to concrete-filled circular hollow sections using Ajax blind bolts. A large-scale T-stub connection with full instrumentation was tested to failure in tension. The favourable strength and stiffness characteristics of this type of connection showed that it could be an alternative to the conventional welded moment connections. A three dimensional finite element (FE) model was developed to simulate the behaviour of blind-bolted T-stub connections. The FE model took into account material nonlinearities, geometrical discontinuities and complex contact interactions among the bolt heads, tube wall, endplate, and nuts. The FE results were found to be in good quantitative agreement with the actual connection behaviour. The cogged extensions to the blind bolts were very effective in relieving the stress concentration on the thin tube wall. Thus, by using the blind-bolted connections with cogged extensions to connect the beam flanges to the column, moment transfer between the beam and column can be effectively achieved within the structural frame of composite construction.
