EFFECT OF RESIDUAL-STRESSES ON PLASTIC BUCKLING OF CYLINDRICAL-SHELL STRUCTURES

Weld-induced residual stresses in shell structures tend to give earlier onset of plastic yielding and to reduce the critical buckling load. Geometrical imperfections may also have a detrimental effect on the load carrying capacity. The interaction between these two kinds of imperfections is studied here for various longitudinally welded cylindrical shell structures, with focus on short wave local buckling modes. It is found that structures with reduced bifurcation loads due to residual stresses show less sensitivity to geometrical imperfections, and after buckling mode deflections of the order of the shell thickness, the residual stresses play no role at all. © 1990.