Efficient Analysis of 3D Mixed-Mode Cracks of a Pressure Vessel Based on Schwartz-Neuman Alternating Method

Abstract:

The Schwartz-Neuman alternating method is employed to analyze 3D cracks in structural components with complicated geometries.The SIFs of Mode I, II and III for the mixed-mode cracks under complicated stress state are obtained from the alternating computing scheme between finite element method solution for the uncracked body and the symmetric Galerkin boundary element method solution for the crack in an infinite body. The SIFs of the different surface cracks postulated at a regular pipe and elliptical surface cracks at the nozzle-cylinder intersection of a typical reactor pressure vessel are investigated by using the Schwartz-Neuman alternating method. The comparison with other analysis models and results reported in the literature shows that the Schwartz-Neuman alternating method can efficiently and accurately evaluate SIFs of surface cracks of different shapes and depths with much smaller computational models, which indicates that the Schwartz-Neuman alternating method is an efficient method in the evaluation of the SIFs of 3D cracks.

• Periodical: Applied Mechanics and Materials (Volume 853)
• Pages: 266-271
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.853.266
• Online since: September 2016
• Authors: Qing Du, Guang Yu Shi*
• Keywords: 3D Fracture Mechanics Model, Efficient Fracture Analysis Model, Mixed-Mode Surface Crack, Pressure Vessel, Schwartz-Neuman Alternating Method, Stress Intensity Factor

References

[1] Z D Han, S N Atluri. SGBEM (for cracked local subdomain)-FEM (for uncracked global structure) alternating method for analyzing 3D surface cracks and their fatigue growth, CMES: Comput. Model. Eng. Sci. 3 (2002) 699-716.

[2] G P Nikishkov, J H Park, S N Atluri. SGBEM-FEM alternating method for analyzing 3D non-planar cracks and their growth in structural components, J. CMES: Comput. Model. Eng. Sci. 2 (2001) 401-422.

[3] Chinese Institute of Aviation Research Manual of Stress Intensity Factors, Science Press, Beijing, 1993. (in Chinese).

[4] U T Murtaza, M J Hyder. The effects of thermal stresses on the elliptical surface cracks in PWR reactor pressure vessel, J. Theor. Appl. Fract. Mec. 75 (2015) 124–136.

DOI: 10.1016/j.tafmec.2014.12.001

[5] K Kiss, L Dunai. Fracture mechanics based fatigue analysis of steel bridge decks by two-level cracked models, J. Comput. Struct. 80 (2002) 2321-2331.

DOI: 10.1016/s0045-7949(02)00254-7

[6] ASME Boiler and Pressure Vessel Code, Section III, Division 1, Appendix G: Fracture toughness criteria for protection against failure. New York, (2010).