Interlaminar shear stresses in balanced and symmetric laminates with free edges and failure due to these stresses were studied. It was shown that the average in terlaminar shear stress τxz near the free edge is linearly related to the mismatch of the extension-shear coupling of the top and bottom sublaminates separated by the interface of interest. A simple failure criterion based on the mismatch of the extension shear coupling was introduced to predict laminate failure stress and strain. The validity of this criterion was verified by experiments using AS4/3501-6 graphite/epoxy composite laminates.
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References
1.
Pipes, R.B. and N.J. Pagano1970 "Interlaminar Stresses in Composite Laminate under Uniform Axial Extension," J. Composite Materials, 4.538-548.
2.
Rybicki, E.F.1971. "Approximate Three-Dimensional Solutions for Symmetric Laminates under Inplane Loading," J. Composite Materials, 5:354-365.
3.
Pipes, R.B. and I.M. Daniel.1971. "Moire Analysis of the Interlaminar Shear Edge Effect in Laminated Composites," J. Composite Materials , 5:255-259.
4.
Pagano, N.J. and R.B. Pipes.1973. "Some Observations on the Interlaminar Strength of Composite Laminates," International J. Mechanical Sciences, 15:679-688.
5.
Wang, A.S.D.1977. "Some New Results on Edge Effect in Symmetric Composite Laminates," J. Composite Materials , 11:92-106.
6.
Hsu, P.W. and C.T. Herakovich .1977. "Edge Effects in Angle-Ply Composite Laminates," J. Composite Materials, 11:422-428.
7.
Newaz, G. M., ed. 1991. Delamination m Advanced Composites. Lancaster, PA: Technomic Publishing Company, Inc.
8.
Sun, C.T. and S.G. Zhou.1988. "Failure of Quasi-Isotropic Composite Laminates with Free Edges," J. Reinforced Plastics and Composites , 7:515-557.
9.
Zhou, S.G. and C.T. Sun.1990. "Failure Analysis of Composite Laminates with Free Edge," Journal of Composites Technology & Research , 12(2):91-97.
10.
Soni, S.R. and R.Y. Kim.1986. "Delamination of Composite Laminates Stimulated by Interlaminar Shear," in Composite Materials: Testing and Design Seventh Conference, ASTM STP 893, J. M. Whitney, ed., Philadelphia: American Society of Testing and Materials, pp. 286-307.
11.
Herakovich, C.T. , A. Nagartar and D.A. O'Brien.1979. "Failure Analysis of Composite Laminates with Free Edge," Modern Developments in Composite Materials and Structures, Winter Annual Meeting of ASME, pp. 53-66.
12.
Herakovich, C.T.1982. "Influence of Layer Thickness on the Strength of Angle-Ply Laminates," J. Composite Materials , 16:216-227.
13.
Herakovich, C.T.1981. "On the Relationship between Engineering Properties and Delamination of Composite Materials," J. Composite Materials, 15:336-348.
