Notes on Incremental Collapse in Pressure Vessels

A few simple cases of incremental collapse are reviewed in the context of the design of pressure vessels. Incremental shakedown and limited-life design in terms of an allowable aggregate strain are considered. It is suggested that incremental collapse will commonly impose limitations on design which will be much more severe than high strain endurance. However it is considered that this may not be true if the high strain fatigue is complicated by questions of creep relaxation.Simple results are presented of two selected examples of exploratory experiments, one illustrating incremental collapse in a pipe bend, and the other incremental shakedown in a tie-plate.