Lateral-torsional buckling curves for monosymmetric steel cross-sections

Abstract

The stability design of beams and columns is generally treated in international design codes, such as Eurocode-3, by using –for all buckling cases- the same curves used for column buckling. One prominent example is the use of the European column buckling curves for the design of steel members against Lateral-Torsional Buckling. During the national implementation of Eurocode-3, the code provisions for the design of steel members against LT-Buckling have once again come under scrutiny by the scientific community. The work presented in this thesis is to be seen in the context of this scrutiny. Expanding on recent findings of the Institute for Steel Structures and Shell Structures at Graz University of Technology on the LT-Buckling strength of bi-symmetric I- & Hsections, this thesis aims at providing the numerical basis for the development of a Eurocode-conform design formulation for monosymmetric steel cross-sections subjected to bending loads that is mechanically more consistent and accurate than the current regulations. For this purpose, the following steps will be taken: 1) Review of existing design concepts: literature study, code comparison. 2) Development of appropriate numerical (FEM) models using the software package ABAQUS and a tool that automates the numerical processes. 3) Numerical parametric study of the global buckling mode, both in terms of elastic critical buckling loads and of realistic GMNIA elasto-plastic buckling loads. The parametric study will clarify the differences in behaviour of mono- and bi-symmetric cross-sections, and highlight the discrepancies between the actual behaviour and the code regulations. 4) Development of specific Lateral-Torsional Buckling curves for monosymmetric steel cross-sections for possible implementation in design codes and recommendations