Abstract
Experimentally determined crack-opening displacements of stationary and running cracks and of inclined stationary cracks in centrally notched plates are reported in this paper. The moiré-fringe technique was used for the determination of displacement fields in test specimens of magnesium, 7075-T6 and 7178-T6 aluminum alloys. Experimentally determined crack-opening displacements were compared with corresponding re ults based on theoretical models of Westergaard, Dugdale, Craggs and Craggs-Dugdale. In addition, normal-strain fields derived from the moiré-fringe data were compared with static or dynamic strain fields of these theoretical models. The results of this investigation indicate that while the Dugdale crack is a fair model of a stationary crack in ductile materials, the Craggs crack appears to be a better representation of a running crack in the ductile materials investigated.
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Kobayashi, A.S., Engstrom, W.L. & Simon, B.R. Crack-opening displacements and normal strains in centrally notched plates. Experimental Mechanics 9, 163–170 (1969). https://doi.org/10.1007/BF02326565
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DOI: https://doi.org/10.1007/BF02326565