Study of ratchet limit and cyclic response of welded pipe

Puliyaneth, M., Barbera, D., Chen, H. and Xuan, F. (2018) Study of ratchet limit and cyclic response of welded pipe. International Journal of Pressure Vessels and Piping, 168, pp. 49-58. (doi: 10.1016/j.ijpvp.2018.09.004)

Abstract

Ratcheting and low cycle fatigue are failure mechanisms observed in components subjected to cyclic temperature and mechanical loads. Ratcheting is a global failure mechanism which leads to an incremental plastic collapse of the component whereas low cycle fatigue is a localized mechanism which leads to crack initiation. It is exacerbated by grooves, notches and changes in the geometry of the component. To estimate the remaining life of the component and predict its failure mechanism, it is important to understand how it responds to various combinations of cyclic loads. This paper includes investigation of the ratchet limit and the plastic strain range, which is associated with the low cycle fatigue, of a circumferential butt-welded pipe by using the ratchet analysis method which includes Direct Steady Cycle Analysis (DSCA) within the Linear Matching Method Framework (LMMF). The pipe is subjected to a constant internal pressure and a cyclic thermal load. The investigation is carried out by varying 1) material properties of the weld metal (WM); 2) ratio of inner radius to wall thickness; 3) weld geometry. Within the specified ranges, yield stress and the ratio of inner radius to wall thickness affect the ratchet limit curve. The cyclic thermal load plays a crucial role compared to the internal pressure in influencing the ratchet limit curve. It is observed that the pipe experiences thermal ratcheting in the absence of pressure load at lower yield stress values of the WM. The results obtained are combined to create a limit load envelope, which can be used for the design of welded pipes within the specified ranges.

• Item Type: Articles
• Additional Information: The authors gratefully acknowledge the support of the University of Strathclyde, the East China University of Science and Technology, the Natural Science Foundation of China (Grants No.: 51828501) and the 111 Project (B13020) during the course of this work.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Barbera, Dr Daniele
• Authors: Puliyaneth, M., Barbera, D., Chen, H., and Xuan, F.
• Subjects: T Technology > TJ Mechanical engineering and machinery
• College/School: College of Science and Engineering > School of Engineering > Systems Power and Energy
• Journal Name: International Journal of Pressure Vessels and Piping
• Publisher: Elsevier
• ISSN: 0308-0161
• ISSN (Online): 1879-3541
• Published Online: 05 September 2018
• Copyright Holders: Copyright © 2018 Elsevier Ltd.
• First Published: First published in International Journal of Pressure Vessels and Piping 168: 49-58
• Publisher Policy: Reproduced in accordance with the publisher copyright policy