Abstract
Measurements of strain near a crak tip with electrical-resistance strain gages do not usually provide a reliable measure ofK I because of local yielding, three-dimensional effects and limited regions for strain-gage placement. This paper develops expressions for the strains in a valid region removed from the crack tip, and indicates procedures for locating and orienting the gages to accurately determineK I from one or more strain-gage readings.
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Irwin, G.R., “Analysis of Stresses and Strains Near the End of a Crack Traversing a Plate,” {jtJ. Appl. Mech.}, {vn24} ({sn3}), ({dy1957}).
Experimental Techniques in Fracture Mechanics, ed. A.S. Kobayashi, SEM Monograph, Iowa State University Press (1973).
Mannog, P., “Schattenoptische Messung der Spezifischen Bruchenergie wahrend des Bruchvorgangs bei Plexiglas,” Proc. Int. Conf. on the Physics of Non-Crystalline Solids, Delft, The Netherlands, 481–490 (1964).
Theocaris, P.S., “Local Yielding Around A Crack Tip in Plexiglas,”J. Appl. Mech.,37,409–415 (1970).
Barker, D.B., Sanford, R.J. andChona, R., “Determining K and Related Stress-Field Parameters from Displacement Fields,”Experimental Mechanics,25 (4),399–406 (1985).
Sanford, R.J., “A Critical Re-examination of the Westergaard Method for Solving Opening-Mode Crack Problems,” {jtMech. Res. Comm.}, {vn6} ({sn5}), ({dy1979}).
Westergaard, H.M., “Bearing Pressure and Cracks,” J. Appl. Mech.,6 (1939).
Chona, R., Irwin, G.R. and Sanford, R.J., “Influence of Specimen Size and Shape on the Singularity-Dominated Zone,” Fracture Mechanics: Fourteenth Symposium — Volume 1: Theory and Analysis, ASTM STP 791, eds. J.C. Lewis and G. Sines, Amer. Soc. Test. and Mat., I-3–I-23 (1983).
Rosakis, A.J. and Ravi Chandra, K., “On Crack Tip Stress States and Experimental Evaluation of Three-Dimensional Effects,” Cal. Inst. of Tech. Rep., FM-84-2 (March 1984).
ASTM-Standard E399-83, “Standard Test Methods for Plane-Strain Fracture Toughness of Metallic Materials,” 1983 Annual Book of ASTM Standards,03.01,ASTM (1983).
Irwin, G.R., “Plastic Zone Near a Crack and Fracture Toughness,” Proc. 7th Sagamore Conf., IV-63 (1960).
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Dally, J.W., Sanford, R.J. Strain-gage methods for measuring the opening-mode stress-intensity factor,K I . Experimental Mechanics 27, 381–388 (1987). https://doi.org/10.1007/BF02330311
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DOI: https://doi.org/10.1007/BF02330311