Stayed Column with Initial Imperfection

The effect of an initial out-of-straightness on the buckling strength of a single-crossarm stayed column is investigated. A geometrical study of the stayed column is used to determine the relationship between the applied load, lateral deflection and the tension in the stays. The geometrical nonlinear behaviour is included in the analysis by using the finite element method and a mixed incremental and iterative procedure. Numerical examples are used to demonstrate the influence of varying the stayed column parameters on the buckling load, deflection rate, as well as the minimum effective, optimum and maximum possible pretensions. Experimental results obtained from a single-crossarm stayed colum with various initial pretensions in the stays are presented and compared with theoretical results, and good agreement was obtained. The results indicate that the presence of an initial out-of-straightness changes the deflection rate and can significantly reduce the buckling load.