Mode i and II Interlaminar Fracture in Laminated Composites: A Size Effect Study

Marco Salviato, Kedar Kirane, Zdenek P. Baant, Gianluca Cusatis*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

3 Scopus citations


This work investigates the mode I and II interlaminar fracturing behavior of laminated composites and the related size effects. Fracture tests on geometrically scaled double cantilever beam (DCB) and end notch flexure (ENF) specimens were conducted. The results show a significant difference between the mode I and mode II fracturing behaviors. The strength of the DCB specimens scales according to the linear elastic fracture mechanics (LEFM), whereas ENF specimens show a different behavior. For ENF tests, small specimens exhibit a pronounced pseudoductility. In contrast, larger specimens behave in a more brittle way, with the size effect on nominal strength closer to that predicted by LEFM. This transition from quasi-ductile to brittle behavior is associated with the size of the fracture process zone (FPZ), which is not negligible compared with the specimen size. For the size range investigated in this study, the nonlinear effects of the FPZ can lead to an underestimation of the fracture energy by as much as 55%. Both the mode I and II test data can be captured very accurately by the Baant's type II size effect law (SEL).

Original languageEnglish (US)
Article number091008
JournalJournal of Applied Mechanics, Transactions ASME
Issue number9
StatePublished - Sep 1 2019


  • asymptotic behavior
  • brittleness
  • damage
  • delamination
  • ductility
  • fiber-polymer composites
  • fracture mechanics
  • fracture process zone
  • fracture testing
  • scaling
  • size effect law
  • textile reinforcement

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering

Fingerprint Dive into the research topics of 'Mode i and II Interlaminar Fracture in Laminated Composites: A Size Effect Study'. Together they form a unique fingerprint.

Cite this