Damage Tolerance Predictions in a Diminishing Stress Field
Abstract: Cracks growing in spar webs are not as damage tolerant critical as typically predicted. Test evidence and fleet history suggest that cracks can slow and possibly even arrest because the crack driving force drops as the crack grows toward the beam’s neutral axis. In this fiscally austere environment, it is desirable to eliminate any unnecessary inspections and focus efforts on more critical areas. A rigorous program has been undertaken to more accurately characterize the growth of cracks in a diminishing stress field with the goal of eliminating unneeded inspections.