A Simplified Method to Estimate Elastic-Plastic Fracture Mechanics Parameters under Combined Primary and Secondary Stresses

Abstract:

Detailed two- and three-dimensional finite element analyses are performed to develop an engineering method to estimate elastic-plastic J for cracked structures under combined primary and secondary stresses, based on the V-factor. Extensive analyses with a wide range of geometry and load combination are considered. The results suggest important factors affecting the value of the V-factor. The most important one is the load magnitude, parameterized by the proximity of plastic yielding. The second one is the relative magnitude of the secondary stress to the primary stress. Although the effect of material, in particular materials with Lüders strain seems to be present, such an effect could be neglected, compared to those of the above two parameters. Based on the present results, an engineering method to estimate J for combined primary and secondary stress can be proposed using bilinear equations in terms of the above two parameters.

• Periodical: Key Engineering Materials (Volumes 306-308)
• Pages: 655-660
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.306-308.655
• Online since: March 2006
• Authors: Yun Jae Kim, Chang Gyun Oh, Jong Sung Kim, Tae Eun Jin
• Keywords: Combined Primary and Secondary Stress, Finite Element Analysis (FEA), Ĵ-Integral, V-Factor

References

[1] ASME P&PV Code Section III, Division 1, (2004).

[2] R5: an assessment procedure for the high temperature response of structures. Revision 2, British Energy; (1999).

[3] Kumar V, German MD and Shih CF. Development of a procedure for incorporating secondary stresses in the engineering approach. EPRI report NP3607, (1985).

[4] R6: assessment of the integrity of structures containing defects. Revision 3, British Energy.

[5] Smith S D. Comparison of the PD 6493 r-factor with FEA results. TWI report, SINTAP/TWI/1-2, (1997).

[6] Ainsworth RA, Smith SD and Wiesner CS. Treatment of thermal and residual stress in defect assessments. BEGL report, EPD/GEN/REP/0423/99, British Energy, (1999).

[7] R6: assessment of the integrity of structures containing defects. Revision 4, British Energy; (2001).

[8] Ainsworth RA. The assessment of defects in structures of strain hardening materials. Engineering Fracture Mechanics 1984; 19: 633-42.

DOI: 10.1016/0013-7944(84)90096-1

[9] ABAQUS Version 6. 2-1. User's manual. Hibbitt, Karlsson and Sorensen, Inc, RI; (2001).