Lateral-Torsional Buckling of Shear Deformable Monosymmetric Steel I-Section Arches with Elastic Rotational-End Restraints under a Central Concentrated Load

Abstract

This paper investigates the elastic lateral-torsional buckling of shear deformable circular arches of monosymmetric steel I-section with in-plane elastic rotational end constraints under a central concentrated radial load. In previous studies of monosymmetric arches reported in the literature, their ends were considered to be fix-ended or pin-ended in the plane of their curvature. In practice, the ends of an arch are not always fix-ended or pin-ended. The ends of an arch may have elastic restraints provided by elastic foundations or other adjacent structural elements. In addition, Timoshenko shear deformations, which are inevitable for arches with small and moderate slenderness ratios, are not considered in previous studies of the topic. The major contributions of this article are the following: (1) accurate strains and deformed curvatures for monosymmetric arches, including shear deformations, are derived using position vector analysis; and (2) in-plane analyses, including the influences of the elastic rotational end restraints, are successfully carried out in two steps to obtain the accurate axial compressive force, bending moment, and shear force distributions for lateral-torsional buckling analysis. The theoretical solutions for the lateral-torsional buckling load are obtained by applying the principle of stationary potential energy together with a Rayleigh-Ritz formulation and validated by ANSYS version 15.0 modeling of the problem.