numerical modelling, a bend, a plate, a stiff-plastic model, applicability, an elastoplastic model, a geometrically linear statement, a geometrically nonlinear statement, static deformation, dynamic deformation, the limiting conditions (states).

This work is devoted to a research of a dynamic and quasistatic bend of plates at small and big deflections using elasto-plastic and stiff-plastic deformation models in the geometrically linear and nonlinear statements. The decision of the problems of a bend was carried out by a numerical method on the basis of a model of the covers of Timoshenko’s type theory. As a result of the comparative analysis it is shown that the stiff-plastic model at classical geometrically linear statement is inapplicable for an estimation of the maximum deflections of the elasto-plastic plates. The applicability borders of the stiff-plastic models are defined at the considerable deflections of the simply supported round plates.