Torsion of tubes with quasi-polygonal holes using complex variable method

Abstract

In this paper, torsional analysis of hollow bars with specially shaped non-circular cross-sections is presented. The well-known formulation of the torsion problem in complex variable theory is used to obtain an expression for shear stresses, angle of twist and cross-sectional warping. The most important part of the solution of the torsion problem here is to obtain an appropriate closed-form conformal mapping for specially shaped cross-sections. The obtained mapping is used to achieve a solution for torsion problem of bars with specially shaped hollow cross-section. Finally, the calculated results are compared with the finite-element method solution. The presented solution is capable of accurately predicting the angle of twist, warping, and shear stress in the studied hollow bars.