The Analysis On Elastic And Plastic Stability Of Cylindrical Shells

In this paper, some major research directions in the stability theory of thin shells were introduced, as well as the progress of research in plastic stability field. Both the isotropic-hardening J2 flow theory and the J2 deformation theory were established, and then comparison were given between the two theories. By spreading the incremental stress-strain expressions of both the two theories, some uniform matrix expressions were obtained.The cylindrical shell is the most common structural form of shells, Compared with general shells, since for cylindrical shells the geometrical equations are mostly simplified in forms, so the buckling of cylindrical shells is playing an important role in structural stability, which has increased great development in the theories of structural stability.Based on the nonlinear geometric equations, equilibrium relations, and the two plastic constitutive relations obtained respectively, as well as the linearized buckling mode, the basic equations of plastic buckling were presented, and the simplified buckling equations were also obtained for the axisymmetric case.With the ordinary boundary conditions, the numerical solution was presented for the problem of axisymmetric buckling. By the iterationalgorithm, variable coefficients of buckling differential equations became const coefficients, so that with the method of Galerkin the eigen system solution was available for the limit loads of the buckling problem. Finally the numerical results were compared with the existing testing results in the same case of cylindrical shells.