Popis: |
In this paper, a fatigue test of a X80 pipeline steel specimen with a semi-elliptical defect was performed to study the fatigue propagation stages of the Surface cracks. Based on the obtained test data, a three dimentional finite element procedure was developed for the crack growth estimation of the surface crack in the specimen. In the numerical analysis of crack growth, both the crack depth direction and the surface direction were investigated by using two different evolution equations. The stress intensity factors along the crack front were determined by applying the virtual crack closure technique. The predictions of crack growth were compared with the test data. |