Experimental characterisation of mixed mode traction-displacement relationships for a single carbon composite Z-pin

M. Yasaee*, J. K. Lander, G. Allegri, S. R. Hallett

*Corresponding author for this work

Research output: Contribution to journalArticle (Academic Journal)peer-review

62 Citations (Scopus)
342 Downloads (Pure)


This paper presents an experimental characterisation of the mechanical performance and behaviour of through-thickness reinforced composite laminates. To achieve this, composite blocks with individual reinforcing pins were manufactured, quality assessed and tested. Individual specimens were inspected using X-ray Computed Tomography and only the specimens with acceptable quality pin insertions were tested experimentally under a range of mode mixities. Two stacking sequences, uni-directional (UD) and quasi-isotropic (QI) were investigated. It was found that the pins inside the UD samples experienced significantly larger pin/matrix bond strength than those in the QI laminates. The resulting experimental data indicates that a non-UD laminate type may experience pin pull-out and thus increased energy absorption for a wider range of mode mixities than a UD laminate type. Energy plots show a clear transition from a pull-out to a pin rupture region for both laminate types. Specimens that experienced pin rupture during low mode mixity tests exhibited similar failure energies to those loaded in pure mode II. © 2014 Elsevier Ltd.

Original languageEnglish
Pages (from-to)123-131
Number of pages9
JournalComposites Science and Technology
Early online date6 Feb 2014
Publication statusPublished - 9 Apr 2014

Structured keywords

  • Composites UTC


  • A. Structural composites
  • B. Delamination
  • C. Damage mechanics
  • C. Fibre bridging
  • Z-pinning

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