Edinburgh Napier University

  The results of small and large-scale torsion tests on rectangular section tubes with circular wall perforations are presented and discussed. Perforations are shown to cause the torsional resistance to be re-duced by up to 60% and stiffness to be reduced by up to 40%. The perforated zone is shown to be much more flexible than the unperforated section, which results in severe deformations in this region. Small holes cause small reductions in the torsional resistance and stiffness, but in some instances result in a large reduction in the torsional ductility of the member. The experimental results are favourably compared to the predictions of finite element models, which are then used to demonstrate the importance of the boundary conditions for the asymmetrical cases, and to study in more detail the stress distributions around the openings.