Plastic collapse moment of 90° long radius elbows with internal circumferential surface crack at intrados under in-plane bending

Plastic limit loads for pipe bends with circumferential through-wall crack under torsion moment

“…It can be seen that for large crack θ/π＞1/2, the limit loads are close to each other, whereas varies a lot for small crack θ/π＜1/2 and the differences become more and more significant with θ/π decreasing. 1.0 r/t=5, R/r=2 r/t=5, R/r=4 r/t=5, R/r=6 r/t=10, R/r=2 r/t=10, R/r=4 r/t=10, R/r=6 r/t=20, R/r=2 r/t=20, R/r=4 r/t=20, R/r=6 r/t=5, R/r=2 r/t=5, R/r=4 r/t=5, R/r=6 r/t=10, R/r=2 r/t=10, R/r=4 r/t=10, R/r=6 r/t=20, R/r=2 r/t=20, R/r=4 r/t=20, R/r=6 In the past years, the weakening factor W is evaluated to express the loading capacity for pipes and pipe bends containing defects [7,42,58]. This factor indicates the weakening effect of flaw structure and here is defined as the ratio of plastic limit loads of cracked pipe bends and plastic limit loads of defect free pipe bends with same geometry.…”

“…Hong et al [41] quantified the effect of internal pressure on plastic loads for elbows based on that proposed by Kim et al [17]. Prabhakaran et al [42] obtained the results of plastic moments of elliptical shaped part-through circumferential cracks at the intrados of elbows under in-plane bending moment which covers most range of elbows in crack size used in the nuclear industry.…”