Development of a physics-based theory for mixed mode I/II delamination onset in orthotropic laminates

Z. Daneshjoo, L. Amaral, R. C. Alderliesten*, M. M. Shokrieh, M. Fakoor

*Corresponding author for this work

Research output: Contribution to journalArticleScientificpeer-review

16 Citations (Scopus)
110 Downloads (Pure)


This paper demonstrates how the critical strain energy density in the delamination tip vicinity may be used to explain the physics of delamination growth under mixed mode I/II. A theory previously proposed to physically relate mode I and mode II delamination growth is further extended towards describing the onset of mixed mode I/II delamination. Subsequently, data from the literature is used to demonstrate that this new concept of the critical strain energy density approach indeed explains, based on the physics of the problem, the strain energy release rate level at which crack onset occurs. This critical strain energy density for the onset of delamination appears to be independent of the opening mode. This means that, in order to characterize the fracture behaviour of a laminate, fracture tests at only one loading mode are necessary. Because the load level at which the physical delamination onset occurs at the microscopic level is much lower than the traditional engineering definition of macroscopic onset, further work must reveal the relationship between the macroscopically visible delamination onset, and the microscopic onset.

Original languageEnglish
Article number102303
Number of pages10
JournalTheoretical and Applied Fracture Mechanics
Publication statusPublished - 1 Oct 2019

Bibliographical note

Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.


  • Delamination
  • Laminated composite
  • Mixed mode I/II loading
  • Strain energy density


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