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An investigation of the losipescu and asymmetrical four-point bend tests

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Abstract

The Iosipescu shear test, utilizing a notched specimen in bending and a modification—the asymmetrical four-point bend (AFPB) test—were evaluated as shear tests for composites. This paper summarizes the results of an extensive numerical and experimental investigation of the Iosipescu and AFPB test methods. Finite-element analyses were conducted to assess the influence of notch parameters and load locations on the stress state in the specimen. The shear moduli and the shear strengths were experimentally measured for a quasiisotropic graphite/epoxy laminate using both the Iosipescu and the AFPB test methods. The tests were conducted for various combinations of notch parameters and load locations. The test results indicate that changes in the notch geometry and load locations aimed at improving the stress distribution in the test section resulted in unexpected changes in the failure mode.

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Authors and Affiliations

  1. Aviation Applied Technology Directorate, ARTA (AVSCOM), 23604-5577, Ft. Eustis, VA

    B. S. Spigel (Aerospace Engineer)

  2. Department of Mechanical Engineering and Mechanics, Old Dominion University, 23508, Norfolk, VA

    R. Prabhakaran (Professor)

  3. Thermal Structures Branch, NASA Langley Research Center, 23665, Hampton, VA

    J. W. Sawyer (Aerospace Engineer)

Authors
  1. B. S. Spigel
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  2. R. Prabhakaran
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  3. J. W. Sawyer
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Spigel, B.S., Prabhakaran, R. & Sawyer, J.W. An investigation of the losipescu and asymmetrical four-point bend tests. Experimental Mechanics 27, 57–63 (1987). https://doi.org/10.1007/BF02318864

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  • DOI: https://doi.org/10.1007/BF02318864

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