Applications of Iterative Elastic Techniques for Elastic-Plastic Analysis of Pressure Vessels

Abstract

The paper presents an application of iterative elastic techniques for the determination of elasto-plastic stress-strain fields, limit and shakedown loads. The iterative elastic method relies on iterative modification of elastic modulus in regions at which elastically calculated effective stress exceeds material yield strength. The technique is applied first to thick spherical and cylindrical shells under combined pressure and thermal gradient. Results showed good correlation with analytical elasto-plastic solutions. The elastic compensation technique is then applied to predict elasto-plastic stresses and shakedown loads of thin spherical shell with cylindrical nozzle subjected to internal pressure or end-thrust loading. Predicted shakedown loads were found to be in good agreement with the well-known Leckie and Penny results adopted in pressure vessel codes.