The plastica: The large elastic-plastic deflection of a strut

An extension of the theory of the Elastica is developed to determine the shape of a strut (or a cantilever) which undergoes large plastic deflection. The equations governing such a behaviour and known as the Plastica equations are set up and then solved by a perturbation method and by numerical integration. The post-buckling elastic-plastic deformation of a strut after initial elastic buckling is analysed, and some numerical results are given to show the variation of its load-carrying capacity with the development of the plastic region.