| Abstract: | The local strains theory provides the basis for an analysis of the equilibrium states of initially imperfect compressed sheets of elastoplastic strain-hardening material. In the presence of initial imperfections of the sheet geometry there is no clearly expressed limit at which the deflection increases sharply. Such a limit, corresponding to the critical stress in the linear theory of plates and shells, emerges as the initial imperfection parameter tends to zero. The difference between the total transverse deflections of the initially imperfect and ideal sheets reaches a maximum at the stress level corresponding to this limit. Beyond this limit the initial imperfection effect is important at leastic and weakly developed plastic strains but diminishes considerably as the plastic strain level develops.Institute of Polymer Mechanics, Academy of Sciences of the Latvian SSR, Riga. Translated from Mekhanika Polimerov, Vol. 4, No. 5, pp. 897–905, September–October, 1968. |
