Implications of Limit Analysis on the Evaluation of Locally Thinned Vessels and Pipes

The evaluation of locally thinned vessels and pipes by Design-by-Analysis is currently not well defined in Section III. The present paper uses limit analysis results to study plastic failure mechanisms in a locally thinned cylinder. Parameters studied include the axial and circumferential extent of the thinned region, the amount of available reinforcement outside the thinned region and the circumferential distribution of thinning. On this basis, the amount of thinning justifiable within Section III margins for limit analysis is studied. Implications for Code primary stress limits are discussed.Copyright © 2009 by Atomic Energy of Canada Limited