Journal Published Online: 01 July 2000
Volume 22, Issue 3

Scaling of First-Ply Failure and Strength in [+ϑ /−ϑ/−ϑ /90/90 ] Laminates: Experiments and Predictions



An experimental investigation of first-ply failure and strength was conducted on ply-level scaled carbon/epoxy composite laminates having a stacking sequence of [+ϑn/−ϑ/−ϑn/90/902n]s where the constraint ply angle, ϑ, was varied from 0 to 75°, and where the constraint ply angle, ϑ, was varied from 0 to 75°, and n varied from 1 to 4. First-ply failure was shown to depend on the level of constraint and the scale factor, n. The strain energy release rate for matrix microcracking was computed from first-ply failure data of the [02/902]s laminate. Then, first-ply failure for all other layups was predicted using a numerical model that accounted for both constraint and size. Tensile strength was predicted using a strain energy release rate model for delamination of surface angle plies. A delamination energy value for each ply angle was calculated from the thinnest (n = 1) laminates to predict strength of the other sizes.

Author Information

Lavoie, JA
Virginia Polytechnic Institute and State University, Blacksburg, VA
Morton, J
Defence Evaluation and Research Agency, Farnborough, Hampshire, UK
Pages: 8
Price: $25.00
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Stock #: CTR10635J
ISSN: 0884-6804
DOI: 10.1520/CTR10635J