The Effect of Uniform and Non-uniform Torsion in Thin-Walled Structures

Abstract

In the recent time, the application of thin-walled structures has become more common as a construction element for the steel structures for buildings, bridges or other complex structures. The thin-walled structures has the advantage of reduced self-weight and thus helps to minimize the building materials. As the thin-walled sections are made of slender plates and have different stresses, modes of failure and deformations than the standard hot rolled sections, the effect of torsional loading is an important aspect to study as the thin walled open sections has low torsional rigidities and thus torsion has been the subject of theoretical and practical interest and this research field is still in development from the contribution of the basic theories of Saint Venant to Vlasov theory of torsion to the development of computer simulations. In case of uniform torsion, the warping displacement and the angle of twist rate remains constant in all cross-sections, but in more realistic cases, when the beam are assigned with boundary conditions, the angle of twist rate and the axial displacement along the axis do not remain constant and such structures experience warping moments and warping torques. Thus torsion is an important aspect to be considered in the accurate design of such members as the warping of sections cannot be neglected. So in the present work an attempt has been made to study the effect of uniform and non-uniform torsion on thin-walled beam structures and the different approaches adopted to analyse such problems with two different numerical examples of pure torsion and calculation of stresses.