Development of Structural Evaluation Criteria for Bellows
A method of calculating bounds for the accumulated membrane and bending strains due to creep ratcheting in convoluted bellows was derived for Atomics International Division of North American Rockwell. The solution includes the effects of internal pressure and cyclic displacement loads, each of which produce both membrane and bending stresses in the curved wall of the bellows.
Bounds on the incremental inelastic strains were obtained for both elastic-plastic and creep conditions. The combined rupture damage and creep fatigue damage was kept under acceptable limits to obtain the desired operating life.