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RESIDUAL LIFE ASSESSMENT OF ELBOW WITH VOLUMETRIC SURFACE DEFECT UNDER CYCLIC INNER PRESSURE. Yukhymets Petr Sergejevich Paton Welding Institute (Kiev) yukhymets@paton.kiev.ua. Stress concentation factor. Defect and its modeling with half-ellipsoid. Fatigue curve. RESIDUAL LIFE ASSESSMENT.
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RESIDUAL LIFE ASSESSMENT OF ELBOW WITH VOLUMETRIC SURFACE DEFECT UNDER CYCLIC INNER PRESSURE Yukhymets Petr Sergejevich Paton Welding Institute (Kiev) yukhymets@paton.kiev.ua
Stress concentation factor Defect and its modeling with half-ellipsoid Fatigue curve RESIDUAL LIFE ASSESSMENT Cyclic stress range [N]
Nominal strains elbow (circular ring, h=const) straight pipe (circular ring, h=const) ei
Torus geometry Elbows measuring results Elbow III thickness distribution extended zone Thicness, mm φ, rad compressed zone
Experimental and calculated strains NNP NNP corrected σφ, MPa φ, rad
Experiment details Fatigue crack Strain rate on the defect surface(P=0.1 MPa) Load history
Fatigue damage estimation Fatigue curve (σt = 524 MPa,σy = 327 MPa, Ψ = 49%) σa, MPa N, cycle