Prediction of shape change of corner crack by fatigue crack growth circles

• We develop an efficient new technique for predicting the shape change of a crack.
• The crack growth is perpendicular to both the current and next new crack front.
• Stress intensity factors are interpolated from the values in the database.
• Accurate results can be obtained with much fewer crack front increments.

As a fatigue crack grows, its shape changes. Conventional method for predicting the shape change typically requires the computation of several hundred increments to get accurate results. In this paper, a new finite element simulation technique that uses fatigue crack growth circles is developed. Since the circles are perpendicular to the new crack front as well as to the current crack front, they can represent the real path of the fatigue crack well and yield more accurate results. The new technique is validated by applying it to the case of a quarter-elliptical corner crack in a plate with an open hole subjected to tension loading. The effect of the Paris–Erdogan exponent is also investigated.

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