FEM analysis of stability problem of tapered beam-columns

Abstract

This paper deals with theoretical and numerical analysis of tapered beam-columns subjected to a bending moment and axial force. A standard FEM code COSMOS/M has been used for numerical analysis of a critical load factor. The critical force of an axially loaded tapered column has been calculated as for a uniform member just with an additional factor n α . In the same way, a critical bending moment of the tapered column subjected to pure bending has been determined by using an additional factor m α , only. A lot of simulations with a wide range of the ratios of second moments of area have been carried out to determine the correct values of these two factors. For practing engineers, solution of such kind of problems is easier in case, if an equivalent cross-sectional height tr h is used. As a practical example, analysis of the space stability problem of an industrial column with a variable I−section is presented. In this case, an equivalent cross-sectional height obtained from the numerical solution has been effectively applied.