Uncoupled Torsion of Thin-Walled Sections

Abstract

Pure bending-free torsion of a prismatic bar requires that the axis of twist be located at the shear centre of the section. However, finding the position of the shear centre in an asymmetric section is not a trivial task and corresponds to a complete bending or torsion analysis. By isolating the contribution from the axis of twist to the warping displacement distribution, the shear centre is determined from the solution to the related problem with the axis of twist at the origin. It is then necessary only to correct this solution for torsion about the shear centre rather than to re-solve the whole problem. Network theory is employed extensively in the solution.