In this paper by using the theory of elasto-plastic processes and adjacent-equilibrium criterion the governing equations of the elasto-plastic stability problem of conical shells are derived. The Bubnov-Galerkin’s method combined with the loading parameter method are applied in solving the mentioned problem. The influence of the hardening characteristics of material on the critical load is investigated.

Vietnam Journal of Mechanics, VAST, Vol. 27, No. 2 (2006), pp. 111-119