Applications of iterative elastic techniques for elastic-plastic analysis of pressure vessels

The paper presents an application of iterative elastic techniques for the d etermination of elasto-plastic stress-strain fields, limit and shakedown lo ads. The iterative elastic method relies on iterative modification of elast ic modulus in regions at which elastically tically calculated effective str ess exceeds material yield strength. The technique is applied first to thic k spherical and cylindrical shells under combined pressure and thermal grad ient. Results showed good correlation with analytical elasto-plastic soluti ons. The elastic compensation technique is then applied to predict elasto-p lastic stresses and shakedown loads of thin spherical shell with cylindrica l nozzle subjected to internal pressure or end-thrust landing. Predicted sh akedown loads were found to be in good agreement with the well-known Leckie and Penny results adopted in pressure vessel codes.