Fatigue strength of glass fiber/epoxy angle-ply laminates with different matrix ductility
Angle ply laminates made up of glass fiber/epoxy plies have a good static strength for laminate angles up to about 45 °. This is due to the limitation of transverse strain in the plies due to constraints exerted by neighboring plies. At laminate angles of 50 ° and above the transverse and shear strains in the plies are not sufficiently constrained and cause failure in the matrix material. The constraint effect is present in fatigue but since the polymeric matrix material is sensitive to fatigue loading fatigue failure will occur at much lower strain levels than in static loading. This effect cannot be offset by increasing the ductility of the matrix material. Thus, strain to failure under fatigue loading will be only a small fraction of the static strain to failure for angle ply laminates with ply angles up to around 45 ° where the static strength is due to the constraint effect.
KeywordsFatigue Ductility Polymeric Matrix Static Loading Shear Strain
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- 1.T. R. Smith and M. J. Owen, “Progressive nature of fatigue damage in RP,” Modern Plastics, May 1969.Google Scholar
- 2.L. J. Broutman and S. Sahu, “Progressive damage of a glass reinforced plastic during fatigue,” 24th Annual Techn. Conf. The Soc. of the Plastic Industry Inc., Section IID, pp. 1–12 (1969).Google Scholar
- 3.J. B. Stugeron, Technical report 75135. Roy. Aircrart Establishment. — Farnborough 1975.Google Scholar
- 4.J. B. Stugeron, Proc. 28th Ann. Techn. Conf. Soc. Plastics Industry, pp. 12–13 (1973).Google Scholar
- 5.H. T. Hahn and R. Y. Kim, “Fatigue behavior of composite laminate,” J. Composite Mater., 10, 156–180 (1976).Google Scholar
- 6.J. Awerbuch and H. T. Hahn, “Fatigue of filamentary composite materials,” ASTM STP 636, 248–266 (1976).Google Scholar
- 7.H. T. Hahn, “Fatigue behavior and life prediction of composite laminates,” Composite Materials: Testing and Design. 5th Conf. ASTM STP 674, 383–417 (1979).Google Scholar
- 8.R. Talreja, “Fatigue of composite materials,” Technomic Publishing Company, Lancaster (1987).Google Scholar
- 9.R. Talreja, “Fatigue of composite materials: damage mechanisms and fatigue-life diagrams,” Proc. R. Soc., London, A 378, 461–475 (1981).Google Scholar
- 10.C. K. H. Dharan, “Fatigue of composite materials,” ASTM STP, 569, 171–188 (1975).Google Scholar
- 11.Z. Hashin and A. Rotem, “A fatigue criterion for fiber reinforced materials,” J. Composite Materials, 448–464 (1973).Google Scholar
- 12.A. Rotem and Z. Hashin, “Fatigue failure of angle ply laminates,” AIAA J.,14, No. 7, 868–872 (1976).Google Scholar