Through-thickness characterization of thick composite laminates

P. M. Schubel*, J. J. Luo, Isaac M Daniel

*Corresponding author for this work

Research output: Chapter in Book/Report/Conference proceedingConference contribution

10 Scopus citations


Interlaminar stresses and strength in composite materials have long been a focus of research because they are related to the common failure mode of delamination. However, the determination of the through-thickness properties of composite materials is not a straightforward process. The through-thickness characterization of composite laminates is becoming increasingly critical for the reliable and robust design of thick composite components used in structural applications. Additionally, the out-of-plane strength parameters of composite laminates are of great importance in the verification of three-dimensional failure theories. In characterizing the through-thickness mechanical properties of a composite, the objective is to produce a state of stress in the test specimen which is uniform and will repeatedly measure the true properties with accuracy. In this study, specimens were machined from thick (∼25 mm) laminates of woven carbon fabric/epoxy and tested in compression, tension and shear. Straight-sided, waisted and V-notched specimens were used for direct load application using specially designed fixtures. In addition to obtaining reliable through-thickness properties of the material (F 3c, F 3t, F 31, etc.), off-axis loading configurations produced a more general 3D state of stress in the test specimen. These through-thickness strength data were used for detailed analysis of the delamination failure process in composite materials and in the development of a new delamination failure theory.

Original languageEnglish (US)
Title of host publicationProceedings of the 2006 SEM Annual Conference and Exposition on Experimental and Applied Mechanics 2006
Number of pages8
StatePublished - Oct 31 2006
EventSEM Annual Conference and Exposition on Experimental and Applied Mechanics 2006 - Saint Louis, MO, United States
Duration: Jun 4 2006Jun 7 2006


OtherSEM Annual Conference and Exposition on Experimental and Applied Mechanics 2006
Country/TerritoryUnited States
CitySaint Louis, MO

ASJC Scopus subject areas

  • Engineering(all)


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