A new method of buckling resistance evaluation of laterally restrained beam-columns

This paper deals with a consistent application of the Ayrton-Perry formulation for the in-plane behavior resulting from flexural buckling and one directional bending of I or H section members. A new analytical model is developed for establishing design criteria. It is based on the decomposition of bending first-order deformations into two components, namely related to the symmetrical loading in case of the first component while the second component is related to the anti-symmetrical loading. The former component is amplified in relation to the lowest bifurcation force amplification factor, while the latter - to the second lowest bifurcation force amplification factor. The results yielding from the developed model are verified using numerical FEM results based on the shell finite element modeling technique. The comparisons of results made available by proposed analytical model and those obtained with use of Eurocode's design criteria are also given. Finally, concluding remarks for future research are also drawn.