Method of Analysis of Laterally Loaded Columns

A numerical method is described for the determination of the critical lengths of homogeneous steel beam columns, the critical length being defined as the length for which the applied axial force becomes the maximum force the member can sustain. In this method, prediction is made of the distribution of the bending moments along the compression members by the use of analytical expressions which describe their slopes. To obtain these analytical expressions, the moment-curvature-thrust relationships of the cross section must be represented by algebraic functions in which the curvatures are expressed explicitly in terms of the moments. The method is general and can be used whenever the moment-curvature-thrust relationships are available. Several examples of columns under the action of end-moments and symmetrical lateral loads have been solved by the proposed approach and comparison with available solutions has shown excellent agreement.