A numerical analysis on the interaction of twin coplanar flaws

In several practical situations, structural components present more than one crack. Such multiple cracks should be considered simultaneously since the interaction phenomenon could produce higher stress-intensity factor (SIF) values with respect to the case of a single crack. In the present paper, the influence of two identical coplanar semi-elliptical surface flaws in a plate with finite width and thickness under various stress distributions perpendicular to the crack faces is numerically analysed. Then the results for such elementary stresses are used to obtain the SIFs for real load cases. Due to the interaction effect, the SIF distribution along the crack front is asymmetric and dependent on the distance δ between the two surface cracks. The distance of non-interaction is evaluated as a function of the crack shape and the crack depth.