Effect of Temperature on Mode I Interlaminar Fracture of IM7/PETI-5 and IM7/977-2 Laminates

Abstract

The mode I critical strain energy release rates, G_IC, of two polymer matrix composites were experimentally measured at temperatures ranging from -196°C to 160°C. The two composite materials investigated in this study were IM7/PETI-5 and IM7/977-2. Double cantilever beam specimens were manufactured with a °[0°₇/ ± 3°/0°₇] lay-up. The experimental results showed that G_I had a strong dependence on temperature above 25°C and minimal dependence on temperature below 25°C. In addition, it was found that IM7/PETI-5 was significantly tougher than IM7/977-2 at all the temperatures investigated. These materials can be considered suitable, in the future, for manufacturing cryogenic fuel tanks in space applications; therefore, understanding critical composite properties such as the interlaminar toughness at such temperatures is very important.

Keywords

cryogenic temperature interlaminar toughness double cantilever beam specimens.

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References

Cytec , `Cycom 977-2 Toughened Epoxy Resin', http://www.cytec.com/business/EngineeredMaterials/Datasheets/CYCOM%20977-2.pdf

Johnson, W.S. and Mangalgiri, P.D. (1987). Investigation of Fiber Bridging in Double Cantilever Beam Specimens, Journal of Composites Technology & Research, 9(1): 10-13.

Melcher, R.J. and Johnson, W.S. (2003). Fracture Mechanics of Adhesively Bonded Polymer Matrix Composites in Cryotank Environments, In: The 14th International Conference on Composite Materials, 14-18 July, San Diego, CA.

ASTM D 5528-01 (2003 ). Standard Test Method for Mode I Interlaminar Fracture Toughness of Unidirectional Fiber-reinforced Polymer Matrix Composites, In: Annual Book of ASTM Standards, Vol. 15.03, pp. 280-291, ASTM, USA.

Reeder, J. (1993). Bilinear Failure Criterion for Mixed-mode Delamination , In: Camponeschi, E.T. (ed.) Composite Materials: Testing and Design, ASTM Special Technical Publication, ASTM Philadelphia, Pittsburgh, PA, No. 1206, pp. 303-322.

Melcher, R.J. and Johnson, W.S. (2007). Mode I Fracture Toughness of an Adhesively Bonded Composite-composite Joint in a Cryogenic Environment , Composite Science and Technology, 67: 501-506.