In N-494,by using specially defined L r as sbacissa, the scatter of FAC for piping containing circumferential crack is reduced compared to that using S r as sbacissa,especially for θ/π≤0 5.The N-494 FAC can assure ...In N-494,by using specially defined L r as sbacissa, the scatter of FAC for piping containing circumferential crack is reduced compared to that using S r as sbacissa,especially for θ/π≤0 5.The N-494 FAC can assure the safety and reasonableness of assessment when θ/π≤0 5.But the applicable range for N-494 FAC is limited in θ/π≤0 5, otherwise the assessment accuracy is worse. Since the material stress-strain relationship used in N-494 is weaker than that of real material, so that the FAC is over conservative. Therefore, more accurate FAC for piping containing circumferential crack of any size should be developed.展开更多
Two kinds of FACs which contain the crack configuratrion parameter were developed, to reflect the fact that the exact J-integral FACs of the circumferentially cracked pipe for different crack configuration are wide sc...Two kinds of FACs which contain the crack configuratrion parameter were developed, to reflect the fact that the exact J-integral FACs of the circumferentially cracked pipe for different crack configuration are wide scattering, especially for load with bending moment. One is the FAC described by material stress-strain parameter and crack configuration parameter, which is similar to R6 op.2 FAC. Another is the general FAC containing crack configuration parameter, which is similar to R6 op.1 FAC. The accuracy and the science significance of those FACs were idscussed in detail in this paper. Not only those FACs take on the advantages of R6 FACs, but also the accuracy of them is better than R6 FACs for defect assessment of piping containing circumferential flaws.展开更多
文摘In N-494,by using specially defined L r as sbacissa, the scatter of FAC for piping containing circumferential crack is reduced compared to that using S r as sbacissa,especially for θ/π≤0 5.The N-494 FAC can assure the safety and reasonableness of assessment when θ/π≤0 5.But the applicable range for N-494 FAC is limited in θ/π≤0 5, otherwise the assessment accuracy is worse. Since the material stress-strain relationship used in N-494 is weaker than that of real material, so that the FAC is over conservative. Therefore, more accurate FAC for piping containing circumferential crack of any size should be developed.
文摘Two kinds of FACs which contain the crack configuratrion parameter were developed, to reflect the fact that the exact J-integral FACs of the circumferentially cracked pipe for different crack configuration are wide scattering, especially for load with bending moment. One is the FAC described by material stress-strain parameter and crack configuration parameter, which is similar to R6 op.2 FAC. Another is the general FAC containing crack configuration parameter, which is similar to R6 op.1 FAC. The accuracy and the science significance of those FACs were idscussed in detail in this paper. Not only those FACs take on the advantages of R6 FACs, but also the accuracy of them is better than R6 FACs for defect assessment of piping containing circumferential flaws.
