Improved Stress Intensity Solutions Developed for the Multiple Site Damage Scenario: Two Unequal Through Cracks on Either Side of an Open Hole, Multiple Through Cracks, and Through Cracks Approaching an Open Hole.

摘要

This report documents work performed to develop new, improved stress intensity factor (K) solutions for geometries that may be useful as components of a more complex solution for the multi-site damage geometry. These solutions include: * Two, unequal through cracks on either side of an open hole in an infinite plate * Multiple through cracks along a plane in an infinite plate * Through crack approaching an open hole in an infinite plate. The solutions were developed using existing handbook solutions (where possible) and were modified as needed based on K-solutions obtained from finite element (FE) validation models. A wide range of geometric parameters, compatible with typical hole spacing values used in actual aircraft structures, were used for the FE models. The improved solutions for all three cases are shown to be within 3 percent of the FE model results obtained as a part of this effort. The majority of the cases are within 1 percent of these results.