Application of Elastic-Perfectly Plastic Analysis to Assessment of Creep Strain

ABSTRACT:

A cyclic elastic-perfectly plastic analysis method is proposed which provides a conservative estimate to cyclic creep strain accumulation within the ratchet boundary. The method is to check for ratcheting based on an elastic-perfectly material with a temperature-dependent pseudo yield stress defined by temperature, time and stress to give 1% accumulated inelastic strain. It does not require stress classification and is also applicable to a full range of temperature within and below the creep regime. This simplified method could be used as a rapid screening calculation, with full time-dependent creep analysis used if necessary. An ASME Boiler and Pressure Vessel Code, Section III draft Code Case based on this simplified method is introduced.

P. Carter, T.L. Sham and R.I. Jetter, “Application of Elastic-Perfectly Plastic Analysis to Assessment of Creep Strain”, Proceedings of ASME 2012 Pressure Vessels & Piping Conference, PVP2012-78082, Toronto, 2012.