Effect of hole on torsional strength for t-shaped joint under torsion

In this paper, the elastic-plastic collapse of T-shaped joints subjected to torsional loading is studied by using the finite element method. The effects of a hole existing in the main tube are investigated. Especially, it is found that when there is no hole in the main tube, the maximum torsion moment M peak is equal to that of the corresponding pure tube, however, when there is a hole, the maximum torsion moment becomes smaller and changes with the width ratio B/b. The cause of the maximum torsion moment fall is because of a deformation δz in z-direction of the upper surface of the main tube. In order to evaluate the influence of the hole quantitatively, parameter Gd showing the geometric characteristic of joint was defined, and a loss ratio μ of the maximum torsion moment is given as a function of G d.