BOUNDARY EFFECT AND WELD REINFORCEMENT OF LARGE OPENING WITH FLUSH NOZZLE IN ELLIPSOIDAL HEAD PRESSURE VESSEL

摘要

By the analysis of the single and double boundary effect of the large opening structure with flush nozzle in pressure vessel with ellipsoidal head in terms of Thin Shell Theory, stress distribution of the two cases are obtained in this paper. Then numerical and experimental verifications are carried out by finite element method (FEM) and experiments. Comparing theoretic and numerical results with experimental data respectively; it is found that FEM or theoretic results accord with the experimental data well, while there is some non-consistence between the FEM or theoretic results and the experimental data within joint range. According to the consistence between the analysis results of FEM and those of thin shell theory in weld roots, a newly weld reinforce effect calculation approach of the welt joint is proposed by considering the size of the weld joint and using the results of thin shell theory in the roots of the weld. Example presented indicates that, as a quick and convenient evaluation means, using the results of thin shell theory in weld root to evaluate joint strength is available and reliable.