Alpha-Cr - Ein Programm zur numerischen Berechnung von Stabilitätsfällen in Anlehnung an den Eurocode 3

Alpha_Cr - A program for the numerical calculation of stability problems according to Eurocode 3.

A possible verification method of stability cases of steel constructions, in accordance with EN 1993-1-1 from Eurocode 3 [1] can be found in the determination of reduction factors (c-procedure), and the reduction of the cross section resistance. For the calculation of the reduction factors the bifurcation loads Ncr and Mcr are needed as input values. The analytical determination of these bifurcation loads becomes very complex, for all cases where general boundary conditions and lateral torsional problems needs to be taken into consideration. The literature or the Austrian national application document ÖNORM B 1993-1-1 from Eurocode 3 [2] includes some analytical solutions for the stability problem flexural torsional buckling. These solutions are, from an engineering viewpoint, difficult to understand and cover just a few simple applications, such as the single-span beam under uniformly distributed load. The desire for planning assistance was given.
To cover a broad spectrum of stability cases, numerical methods are used. A program Alpha_Cr for the determination of bifurcation loads, on basis of the Finite Element Method (FEM), was elaborated. The program arose as a part of a diploma thesis [3] at the Department of Steel constructions, Institute for Construction and Material Science at the University of Innsbruck. The aim was, to provide a simple tool for practical engineers, to carry out stability calculations of the daily assessment with reasonable effort.