A Note on the Effects of Voids Upon the Hygral and Mechanical Properties of AS4/3502 Graphite/Epoxy

Abstract

This paper presents the results of an experimental investigation of the effects of voids upon the hygral and mechanical properties of AS4/3502 graphite/epoxy. Simple uniaxial tension tests were employed to determine the effects of voids upon ply moduli E ₁₁, E ₂₂ and G ₁₂, and the Poisson ratio ν₁₂. The matrix dominated moduli E ₂₂ and G₁₂ were found to depend significantly upon void content while little dependence was noted for the fiber dominated properties E ₁₁ and ν₁₂. Moisture conditioning experiments showed that both the rate and the equilibrium level of moisture sorption depend upon void content. In addition, non-Fickian diffusion anomalies were observed in high void content specimens while specimens with low void content displayed classical Fickian behavior.

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