An energy formulation employing total potential energy principles is presented to derive
a governing equation for strength predictions of struts made from materials following
the Ramberg–Osgood constitutive law such as stainless steel, cold-formed steel, and
aluminium alloys. The formula is generic and applicable to arbitrary cross-sections and all
strut slendernesses for which flexural buckling is critical. Extensive comparisons against
experimental data on square and rectangular hollow section struts as well as finite element
simulations demonstrate the accuracy of the developed formula, while the effect of varying
material parameters is examined through comprehensive parametric studies. Owing to
its simplicity and its derivation based on mechanical principles, arbitrary configurations
of material parameters and cross-sections can be analysed, making the formula suitable
for use in design practice, representing effectively a non-iterative alternative to the widely
accepted design load employing the tangent modulus. With the aid of the formula, new
column buckling design provisions are developed, which show excellent agreement with
experimental data and meet the reliability requirements specified within the structural
Eurocodes.