Stiffness and fracture analysis of laminated composites with off-axis ply matrix cracking

Maria Kashtalyan, C. Soutis

Research output: Contribution to journalArticlepeer-review

59 Citations (Scopus)


Matrix cracks parallel to the fibres in the off axis plies is the first intralaminar damage mode observed in laminated composites subjected to static or fatigue in-plane tensile loading. They reduce laminate stiffness and strength and trigger development of other damage modes, such as delaminations. This paper is concerned with theoretical modelling of unbalanced symmetric laminates with off axis ply cracks. Closed-form analytical expressions are derived for Mode I, Mode II and the total strain energy release rates associated with off-axis ply cracking in [0/theta](s) laminates. Stiffness reduction due to matrix cracking is also predicted analytically using the Equivalent Constraint Model (ECM) of the damaged laminate. Dependence of the degraded stiffness properties and strain energy release rates on the crack density and ply orientation angle is examined for glass/epoxy and carbon/epoxy laminates. Suitability of a mixed mode fracture criterion to predict the cracking onset strain is also discussed. (c) 2006 Elsevier Ltd. All rights reserved.

Original languageEnglish
Pages (from-to)1262-1269
Number of pages7
JournalComposites Part A: Applied Science and Manufacturing
Issue number4
Publication statusPublished - Apr 2007


  • laminates
  • fracture
  • mechanical properties
  • analytical modelling
  • transverse cracking
  • degradation
  • growth
  • glass
  • microcracks
  • behavior
  • damage


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