Column Buckling Investigation of Plane Frames

Abstract

This paper deals with elastic stability analysis of the plane frame structures. The main aim is to investigate the accuracy of related parts of European and domestic codes for steel and concrete structures. Numerical analysis of frame structures is performed using the self-developed Matlab computer program. Matrix analysis of the whole structure according to the second order theory, based on the application of trigonometric shape functions, is applied. As opposed to that, the dominant approach given in most structural codes is based upon the stability analysis of compressed structural elements isolated from the structure as a whole. Several numerical examples are given in the paper and comparative analyses presented herein show that, in some cases, solutions given in domestic and European codes are rather inaccurate. For example, the error in the determination of the effective buckling length of frame columns can sometimes exceed even 100%. Finally, it is concluded that innovation of actual codes should be done in the part where the effective buckling length of frame columns is considered. Improvement of this calculation could be achieved using the global stability approach and the corresponding calculation of the critical load for complete structure, as it is presented in the paper.