ABSTRACT
Slip-joint connections are made by joining end-to-end slightly tapered tubes. The method also allows inexpensive fabrication and erection methods to be used. Recently the lighting towers of the Ballymore Stadium in Queensland were upgraded using this method. Their heights ranged from 47.5 m to 53.5 m with diameters up to 1.6 m and thicknesses in the range 6 mm to 12 mm. They are also used to support antennas used by cellular mobile phone services.
The paper describes an investigation into the strength of slip-joint connections, focussing mainly upon the overlap length required to ensure that the full capacity of the tube is utilised. The investigation began with a series of experiments, the results of which were analysed by Buckingham’s Pi-Theorem to give design charts. Some attempts at theoretical analyses of the buckling problem are also described. This buckling problem involves some interesting studies of the theory of developable surfaces.
