In one CANDU® nuclear station, a few feeder piping failures have occurred because of stress corrosion cracking. All the cracks were located in tight-radius bends. Root cause analyses indicated that the residual stress played a significant role in these failures. Residual stress measurements using the neutron diffraction technique have been performed to quantify the residual stresses for a large number of feeder bends. Numerical simulations have also been performed to supplement the measurement data. This paper presents the modeling work carried out for 2.5” warm-bent tight-radius feeder bends using LS-DYNA®. The warm-bending process was divided into heating, bending, springback and cooling stages. The simulation results were compared to the measurement data using the neutron diffraction technique. Good agreement was achieved between the trends of simulation results and the measured residual stresses in feeder bends. Additionally, it was found that the predicted cross-sectional shape and wall thickness distribution agreed well with the measurements. Limitations of the simulation work were summarized and recommendations for future research were made based on this study.
Residual Stress Modeling of Warm-Bent Tight-Radius CANDU Feeder Bends
- Views Icon Views
- Share Icon Share
- Search Site
Ding, Y, & Yetisir, M. "Residual Stress Modeling of Warm-Bent Tight-Radius CANDU Feeder Bends." Proceedings of the ASME 2008 Pressure Vessels and Piping Conference. Volume 7: Operations, Applications and Components. Chicago, Illinois, USA. July 27–31, 2008. pp. 449-455. ASME. https://doi.org/10.1115/PVP2008-61113
Download citation file: