Session: CS-16-01 Fatigue and Ratcheting Issues in Pressure Vessel and Piping Design-1

Paper Number: 152062

152062 - Influence of Triaxiality Factor on Low Cycle Fatigue of Pipe Fittings 

Abstract: 

In 2019, ASME Section III and JSME published a remarkable code case (ASME CC N-900/JSME NC1 CC-008) regarding seismic design codes for piping by using elastic-plastic analysis. As shown in PVP2023-107170 "Seismic Design Method of Crossover Piping Across Building Isolation Boundary", while it would be clear that this code case using elastic-plastic analysis allows for a reasonable seismic design of the piping, there are few examples of actual seismic design works by using this code case because of conservative applicable limitations such as fabrication strain limitations and strainbase criteria with applied strain. we have discussed the technical issues to be addressed to revise ASME CC N-900 for actual piping design use and reported some revision proposal on ASME CC N-900. In this paper, we proposed the revisit results on allowable strain amplitude for Reversing Dynamic Load (RDL) with calculation method of applied strain by reversing dynamic loads, based on low cycle fatigue testing and past studies on piping failure mode by Reversing Dynamic Load(RDL). Also, we provided with the sample calculation of triaxiality factor for pipe fittings and fatigue evaluation sample for elbow by Reversing Dynamic Load(RDL) to demonstrate the validity of our revision proposal on ASME CC N-900.

Presenting Author: Kenichi Shibukuwa IHI Corporation

Presenting Author Biography: Kenichi Shibukuwa is a manager at IHI Corporation in Japan. His work focuses specifically on management of maintenance and construction project for Domestic Nuclear Power Plant. He has a lot of expertise in the piping engineering of nuclear power plant for 36 years. Also, He has been active in JSME(The Japan Society of Mechanical Engineers) and JEA(The Japan Electric Association) as code engineer since 2020.

Authors:

Kenichi Shibukuwa IHI Corporation
Jie Wen JENSEN HUGHES