一方向強化炭素繊維/エポキシ樹脂複合材料の引張破壊特性と疲労に及ぼす水環境効果

概要

論文の詳細を見る
An investigation has been carried out concerning the effects of water absorption on the mechanical properties and fatigue strength of two types of unidirectionally reinforced carbon/epoxy composites, i. e., 130℃ cure-type composite T-1/347 and 180℃ cure-type MM-1/982 X. T-1/347 composites absorb more water than MM-1/982X composites. After long immersion of about seven months, however, MM-1/982X composites absorb water rapidly, and the fatigue strength is considerably decrease. In the case of wet specimens of T-/347 composites preconditioned in water for two months, high amount of water absorption degrades the matrix and decreases the strength of the fiber/matrix interface, thereby decreasing the mechanical properties. For MM-1/982X composites, small amount of water absorption moderately decreases the interfacial strength and increases the ductility of the matrix, thereby increasing the mechanical properties. However, fatigue life of wet specimens of both T-1/347 and MM-1/982X composites is decreased in water, but the one of dry specimens proconditioned in laboratory air is increased in water. In these tests, the synthesized evaluation of acoustic emission (AE) signals using several AE parameters and AE signal location have been done, and the fracture mechanisms are discussed in terms of the observations of internal damages by a scanning acoustic microscope (SAM) and of fracture surfaces by a scanning electron microscope (SEM).
1990-05-25