Abstract
A detailed experimental evaluation of the losipescu specimen tested in the modified Wyoming fixture is presented. Moiré interferometry is employed to determine the deformation of unidirectional and cross-ply graphite-epoxy specimens. The results of the moiré experiments are compared to those from the traditional strain-gage method. It is shown that the strain-gage readings from one surface of a specimen together with corresponding data from moiré interferometry on the opposite face documented an extreme sensitivity of some fiber orientations to twisting. A localized hybrid analysis is introduced to perform efficient reduction of moiré data, producing whole-field strain distributions in the specimen test sections.
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References
Iosipescu, N., “New Accurate Procedure for Single Shear Testing of Metals,”J. Mat.,2 (3),537–566 (1967).
Adams, D.F. and Walrath, D.E., “Further Development of the Iosipescu Shear Test Method,”Experimental Mechanics,113–119 (1987).
Lee, S. andMunro, M., “Evaluation of In-plane Shear Test Methods for Advanced Composite Materials by the Decision Analysis Technique,”Comp.,17 (1),13–22 (Jan. 1986).
Adams, D.F. andWalrath, D.E., “Current Status of the Iosipescu Shear Test Method,”J. Comp. Mat.,21,494–507 (June 1987).
Abdallah, M.G. and Gascoigne, H.E., “The Influence of Test Fixture Design of Iosipescu Shear Test for Fiber Composite Material,” Test Methods for Design Allowables for Fibrous Composites,2,ASTM STP 1003, ed. C.C. Chamis, 231–260 (1989).
Kumosa, M. and Hull, D., “FEM Analysis of Mixed Mode Fracture in the Iosipescu Shear Test,” Proc. 6th Int. Conf. on Composite Materials/2nd European Conf. on Composite Materials, Elsevier Applied Science, ed. F.L. Matthews, N.R.C. Buskell, J.M. Hodgkinson and J. Morton,3,243–253 (1987).
Barnes, J.A., Kumosa, M. andHull, D., “Theoretical and Experimental Evaluation of the Iosipescu Shear Test, Comp. Sci. and Tech.,28,251–268 (1987).
Sullivan, John L., “The Use of Iosipescu Specimens,”Experimental Mechanics,28 (3),326–328 (1988).
Wilson, D.W., “Evaluation of the V-notched Beam Shear Test Through an Inter-laboratory Study,”J. Comp. Tech. and Res.,12 (3),131–138 (1990).
Lee, S. andMunro, M., “Evaluation of Testing Techniques for the Iosipescu Shear Test for Advanced Composite Materials,”J. Comp. Mat.,24,419–440 (1990).
Ho, H., Tsai, M.Y., Morton, J. and Farley, G.L., “A Comparison of Popular Shear Test Methods for Composite Materials,” Proc. ICCM VIII (July 1991).
Morton, J., Ho, H., Tsai, M.Y. and Farley, G.L., “An Evaluation of the Iosipescu Specimen for Composite Materials Shear Property Measurement,” J. Comp. Mat., in press.
Pindera, M.J., Choksi, G., Hidde, J.S. andHerakovich, C.T., “A Methodology for Accurate Shear Characterization of Unidirectional Composites,”J. Comp. Mat.,21,1164–1184 (1987).
Guild, J., “The Interference Systems of Crossed Diffraction Gratings; Theory of Moiré Fringes,” Oxford at the Clarendon Press (1956).
Czarnek, R., “Moiré Interferometry,”Structural Testing, SEM,30 (2),195–200 (June 1990).
Morton, J., Post, D., Han, B. andTsai, M.Y., “A Localized Hybrid Method of Stress Analysis,”Experimental Mechanics,30 (2),195–200 (June 1990).
Czarnek, R., “New Methods in Moiré Interferometry,” PhD Diss., Virginia Polytechnic Inst. and State Univ. (1984).
Tsai, M.Y., “Application of Localized Hybrid Methods of Stress Analysis to Some Problems in the Mechanics of Composites,” PhD Diss., Virginia Polytechnic Instit. and State Univ. (1990).
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Ho, H., Tsai, M.Y., Morton, J. et al. An experimental investigation of losipescu specimen for composite materials. Experimental Mechanics 31, 328–336 (1991). https://doi.org/10.1007/BF02325989
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DOI: https://doi.org/10.1007/BF02325989