Drilling Repair Index (DRI) based on two-parameter fracture mechanics for crack arrest holes. (January 2016)

• Record Type: Journal Article
• Authors: Nateche, T.; Hadj Meliani, M.; Matvienko, Y.G.; Pluvinage, G.
• Is Part Of: Engineering failure analysis. Volume 59(2016:Jan.)
• Page Start: 99
• Page End: 110
• Publication Date: 2016-01
• Subjects: Crack arrest hole (CAH) -- Drilling Repair Index (DRI) -- Two parameter fracture -- T-stress -- Volumetric method (VM); System failures (Engineering) -- Periodicals; Fracture mechanics -- Periodicals; Reliability (Engineering) -- Periodicals; Pannes -- Périodiques; Rupture, Mécanique de la -- Périodiques; Fiabilité -- Périodiques; Fracture mechanics; Reliability (Engineering); System failures (Engineering); Periodicals; Electronic journals; 620.112
• DOI: 10.1016/j.engfailanal.2015.08.035
• Languages: English
• ISSNs: 1350-6307

Abstract

Abstract: The most common method of preventing cracks from growing is by making a "drill stop" or crack arrest hole (CAH) at the crack tip. The objective of drilling a hole is to "blunt" the crack tip and reduce the stress concentration at the crack tip. In this paper the following situations are studied: (i) a single hole drilled at a blunt crack tip, (ii) a single hole drilled at a distance r from the crack tip with an orientation angle θ relative to the crack direction and (iii) a second hole called the "stress concentrator reducer hole" drilled symmetrically to the first near to the crack hole. A Drilling Repair Index (DRI) is proposed for evaluation of the efficiency of the CAH method. It is based on two-parameter fracture mechanics. Highlights: Three configurations of crack arrest hole (CAH) are studied. The stress concentration factor, the notch stress intensity factor and the constraint trough effective T stress have been determined. Reduction of stress concentration is maximum when a second hole is drilled near the crack tip at an optimal angle is also efficient Using Two parameters Fracture Mechanics, Drilling Repair Index (DRI) is defined.