Environmental Durability of F/A-18 Graphite/Epoxy Composite

Abstract

An environmental durability trial is being conducted on F/A-18 graphite epoxy composites at five tropical test sites in Australia and Malaysia. Two types of specimen have been exposed in the external tropical environment for periods of up to 9 years and measurements have been made of moisture absorption levels, fatigue durability and residual strength. The maximum level of moisture absorption recorded has been 1.0 wt%. Sandwich beam specimens representative of an aircraft structure, containing different types of damage or simulated repairs, have withstood over 106 fatigue cycles at close to nominal design limit load in the tropical environment. This result indicates that F/A-18 composite structure should be very durable under long term tropical conditions.

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