Stress Intensity Factor Calculation of Ultrahigh Pressure Elbow with Semi-elliptical Cracks

Ultrahigh pressure elbow is a key part of ultrahigh pressure pipeline, because of the processing modeling complexity of ultrahigh pressure elbow, there are some cracks on the surface of inside wall of ultrahigh pressure elbow, so under the effect of internal pressure, the stress field was very complex, Finite element analysis software was used to analyzed ultrahigh pressure elbow with semi-elliptical cracks, the stress distribution near the cracks was gained, and mainly studied the stress intensity factor of ultrahigh pressure elbow with semi- elliptical cracks and analyzed the effect factor, the result showed that the major effect factors on the stress intensity factors of ultrahigh pressure elbow are inside diameter and outside diameter ratio, the dimension of crack, crack angle, and the depth of crack and thickness ratio, and effect on the stress intensity factors of Ro/Ri was maximal, in engineering should be emphatically to consider the impact.