This project developed intelligent flaw interaction rules that can account more accurately the impact of multiple cracks without being overly conservative. These rules use the principles of equivalent impact among multiple interacting cracks and represent the magnitude of the impact by a single virtual crack. These rules do not rely on a critical spacing to determine whether there is an interaction. The magnitude of the interaction is a continuous function of the size of adjacent cracks and the spacing between them.
There is a related webinar.