Variational principle for global stability of elasto-plastic thin shells (Q1179861)

The global stability of thin elastoplastic shells subjected to arbitrary load is investigated, by means of a variational method. The geometric method is developed and applied to determine the asymptotic expression for the energy of the postbuckling deformation and to formulate the variational principle of the elasto-plastic shells. This principle is applied to the determination of the minimum critical load for cylindrical elasto-plastic shell subjected to axial compression. The comparison between theoretical and experimental results shows a small difference of order about 9-17\%, what confirms the validity of the proposed assumptions of the geometrical method and the correct application of the plastic deformation theory for describing the plastic properties of shell material.