GLOBAL RATCHETING BY ELASTIC-PLASTIC FEA ACCORDING TO ASME SECTION VIII RULES

摘要

A framework of global ratcheting is developed for which the ratcheting measure is incremental permanent change of shape of a vessel or component. The changes of shape are such that they reduce the resistance to collapse, and, upon extended cycling, can lead to eventual failure by collapse. A ratcheting check is designed to prevent this failure. This framework fits the ratcheting rules that are currently in the 2010 Section VIII of the ASME B&PV Code. Tools are provided for ratcheting assessment based on this framework, and examples are presented that illustrate their application.