ABSTRACT
Exact analysis of a thin-walled member requires us to treat it as a continuous folded plate, but the mathematical complexities of such an analysis are very cumbersome. Analysis of the buckling behaviour of flat plates loaded by forces acting in their middle plane is rather complex because they are affected by two kinds of non-linearity: geometrical and mechanical. The behaviour of cross-sections and their ideal uses in structural analysis is related to the capability of reaching a given limit state which corresponds to a particular assumption about the state of stress acting on the section. Design codes generally suggest using buckling coefficients that correspond to simple support or free conditions. For a buckling load within the elastic-plastic range, the effect of the stress-strain relationship must be properly taken into account in determining the critical stress.
