Testing the 2-3 shear strength of unidirectional composite

Joel S. Fenner*, Isaac M. Daniel

*Corresponding author for this work

Research output: Chapter in Book/Report/Conference proceedingChapter

1 Scopus citations


In this study, the objective was to measure the “out-of-plane” 2-3 shear strength of unidirectional composite, working within constraints in supplied material geometry. Unidirectional carbon/epoxy composite material was tested using a sandwich-type beam specimen under 3-point bending with a low span-to-thickness ratio to achieve failure under 2-3 shear. Specimens were carefully designed to deliberately cause shear failure near the midplane, avoiding other possible failure mechanisms. A photoelastic coating and post-mortem microscopy were used to verify failures. Results were compared with a simple analytical description of failure and found to have good agreement. Notably, this approach was able to accommodate the limitations of the supplied material (thin sheets) while still providing an accurate means of obtaining the F23 shear strength of the material. The results also imply the possibility of testing the transverse tensile strength (F2t) in lieu of performing a shear test, which is far simpler, and inferring the out-of-plane shear strength F23.

Original languageEnglish (US)
Title of host publicationConference Proceedings of the Society for Experimental Mechanics Series
PublisherSpringer New York LLC
Number of pages8
StatePublished - 2019

Publication series

NameConference Proceedings of the Society for Experimental Mechanics Series
ISSN (Print)2191-5644
ISSN (Electronic)2191-5652


  • Composites
  • Interlaminar
  • Photoelasticity
  • Shear strength
  • Test methods

ASJC Scopus subject areas

  • Engineering(all)
  • Computational Mechanics
  • Mechanical Engineering


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