Plastic buckling of cylindrical shells under biaxial load

The plastic buckling of cylindrical shells under biaxial load was studied using rigid-linear hardening model of anisotropic materials. The constitutive equations were linear when the initial calculation point was assumed to be at the original position of the hardening line. For this suppose, basic equations were established for the plastic buckling of cylindrical shells. A plastic buckling case was then solved for a cylindrical shell with frictionless pin-jointed at the four side boundary by these equations, and an analytical expression of the minimum buckling load was given on the condition of weak anisotropy.