Is there a ply thickness effect on the mode I intralaminar fracture toughness of composite laminates?
Journal article, 2020

The apparent crack resistance curves associated with longitudinal tensile failure of carbon fibre reinforced epoxy composite systems with ply thicknesses of 0.075 mm, 0.134 mm and 0.268 mm are determined experimentally from the size effect law of geometrically similar double edge notch tension cross-ply specimens. An increase in notched strength as a function of the ply thickness and a corresponding increase of the measured intralaminar fracture toughness is observed. This increase is shown to be a consequence of the appearance of split cracks in the thicker 0 degrees plies in the vicinity of the notches. The numerical models developed demonstrate that if the notch blunting mechanisms are properly represented, the laminate strength is well predicted for a constant value of the ply intralaminar fracture toughness. This supports the hypothesis that these mechanisms are responsible for the higher strength of the thicker plies, and that the intralaminar fracture toughness of the 0 degrees plies should not be scaled with the ply thickness.

Finite element analysis

Crack resistance curves

Composite laminates

Intralaminar fracture toughness


C. Furtado

University of Porto

A. Arteiro

University of Porto

Peter Linde

Chalmers, Industrial and Materials Science

B. L. Wardle

Massachusetts Institute of Technology (MIT)

P. P. Camanho

University of Porto

Theoretical and Applied Fracture Mechanics

0167-8442 (ISSN)

Vol. 107 102473

Subject Categories

Applied Mechanics

Other Materials Engineering

Composite Science and Engineering



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