Electronic speckle pattern interferometry has been used to calculate KI and J for compact tension specimens. Automated fringe pattern analysis enables the full field of data to be used with the minimum of operator intervention. Measurements are shown to be accurate to within 10 per cent. The J-measurement procedure employed could form the basis of an automatic fault detection system.
Get full access to this article
View all access options for this article.
References
1.
DudderarT. D.GormanH. J.The determination of mode 1 stress intensity factors by holographic interferometry’, Exp. Mechanics, 1973, 13 (13), 145–149.
2.
MarshallS. J.RixonR. C.CaulfieldM. M.MacKenzieP. M.‘The application of automatic fringe analysis in fracture mechanics’, Optics and Lasers in Engng, 1987, 7, 175–193.
3.
HuntleyJ. M.FieldJ. E.‘Measurement of crack tip displacement field using laser speckle photography’, Engng Fracture Mechanics, 1988, 30 (6), 779–790.
4.
ButtersJ. N.LeendertzJ. A.‘Holographic and video techniques applied to engineering measurement’, J. Measmt and Control, 1971, 4, 349–354.
5.
HolscherC.GulkerG.HinschK.KramerA.NeunaberH.‘The investigation of natural stones under test-conditions by ESPI’, inProceedings of the Society of Photo-optical Instrumentation Engineers, Vol. 863. 1987 (SPIE, Bellingham, Washington), pp. 162–166.
6.
MooreA. J.TyrerJ. R.‘Surface strain measurement with ESPI applied to fracture mechanics’, inProceedings of hologram interferometry and speckle metrology, 1990 (The Society for Experimental Mechanics, Bethel, Connecticut), pp. 192–198.
7.
KobayashiA. S.‘Photoelasticity techniques’, inExperimental techniques in fracture mechanics, Edited by KobayashiA. S., 1973 (Iowa State Press), pp. 126–142.
8.
American Society for Testing and Materials, ‘El290–89 Standard test method for crack-tip opening displacement (CTOD) fracture toughness measurement’, 1989.
BarkerD. B.SanfordR. J.ChonaR.‘Determining K and related stress-field parameters from displacement fields’, Expl Mechanics, 1985, 25 (12), 399–407.
11.
SanfordR. J.‘A critical re-examination of the Westergaard method for solving opening-mode crack problems’, Mechanics Res. Commun., 1979, 6 (5), 289–294.
12.
RiceJ. R.RosengrenG. F.‘Plane strain deformation near a crack tip in a power-law hardening material’, J. Mechanics and Physics of Solids, 1968, 16, 1–12.
13.
TimoshenkoS. P.GoodierJ. N.Theory of elasticity, Third Edition, 1970 (McGraw-Hill), equations 134 and 26, 27.
14.
IrwinG. R.KiesJ. A.‘Critical energy rate analysis of fracture strength’, Welding J., 1954, 33 (4), 193s—198s.
