Session: MF-05-02 Fitness-For-Service and Failure Assessment-2

Paper Number: 123421

123421 - Load Carrying Capacities of Small-Diameter Pipe Bends Under Internal Pressure: Analytical and Computational Predictions 

The performance and embedded conservatism of common modeling approaches used for predicting load carrying capacities were evaluated for small-diameter pipe bends typically found in CANDU reactors.  Comprehensive analyses were conducted using both analytical approach and detailed finite element modelling with commercial code ABAQUS.  Small diameter pipe bends, without and with local wall thinning, under the loading by internal pressure were investigated. The adopted modelling approach incorporated variability in pipe bend geometry and characterization of material properties.

 

The results obtained indicate that load carrying capacities of small-diameter pipe bends, either with or without local wall thinning, but characterized with uniform wall thickness and single parameter material strength, are conservatively predicted with analytical models in principle based on the limit load approach.  However, detailed finite element modelling is necessary for obtaining more accurate predictions of plastic instability pressure for pipe bends with local wall thinning.

 

The reported investigation has provided with valuable technical insights into the modelling approaches presently used for predicting load carrying capacities of small-diameter pipe bends under internal pressure loading, and in addition explored embedded conservatism while recognizing the existence of involved uncertainties.  The results obtained emphasize the importance of detailed characterization of pipe bend thickness and material strength in such engineering predictions.

 

Dear Organizer: 

Note there is the third author for this paper, which was not included with this abstract submission.  We are waiting for this author’s internal approval process to be completed.  We will request to add the author’s details afterwards.  Thank you for your understanding and consideration.

Presenting Author: Nick Robinson Carleton University

Presenting Author Biography: Nick Robinson is a graduate research assistant in the department of mechanical and aerospace engineering, Ottawa, Canada.

Authors:

Nick Robinson Carleton University
Xin Wang Carleton University
Bogdan Wasiluk Canadian Nuclear Safety Commission