SYMPOSIA PAPER Published: 01 January 1991
STP17717S

Mixed-Mode Fracture in Fiber-Polymer Composite Laminates

Source

Mode I, Mode II, and Mixed-Mode I/II interlaminar tests on unidirectional carbon-fiber composites have been conducted using beam specimens. Both a thermosetting-based (an epoxy resin) matrix and a thermoplastic-based (poly(ether-ether ketone)) matrix have been employed. The fracture energy, Gc, has been ascertained and the various correction factors that need to be applied if accurate results are to be obtained are described. Where Mixed-Mode I/II loadings may have been present, the measured value of Gc has been partitioned into the separate GI and GII components. The experimental results all suggest that the partitioning of G on a global energy basis, as opposed to using local stress-field solutions, is the most appropriate for the laminates. Thus, the differences in energy absorption are a consequence of opening as opposed to sliding, and the symmetry, or otherwise, of these motions is not important. It is thus apparent that a global energy analysis is entirely satisfactory and appropriate for these types of systems. Finally, it is also shown that when the failure locus is plotted in the form of GI versus GII then it may be theoretically described by a simple interaction parameter model, where the interaction parameter, Ii, has a linear dependence upon the value of GI/G.

Author Information

Hashemi, S
Imperial College of Science, Technology, and Medicine, University of London, United Kingdom
Kinloch, AJ
Imperial College of Science, Technology, and Medicine, University of London, United Kingdom
Williams, G
Imperial College of Science, Technology, and Medicine, University of London, United Kingdom
Price: $25.00
Contact Sales
Related
Reprints and Permissions
Reprints and copyright permissions can be requested through the
Copyright Clearance Center
Details
Developed by Committee: D30
Pages: 143–168
DOI: 10.1520/STP17717S
ISBN-EB: 978-0-8031-5169-7
ISBN-13: 978-0-8031-1419-7