205 平織CFRP擬似等方積層板の疲労挙動に及ぼす吸水の影響と応力比の影響(OS6-(2) 複合材料の変形と破壊およびマルチスケール計算技術,オーガナイズドセッション)

Abstract

The effect of water uptake on the constant amplitude fatigue behavior of a quasi-isotropic plain-woven CFRP laminate at different stress ratios has been examined. First, constant amplitude fatigue tests are performed at room temperature on the specimens immersed in hot water until saturation and on the specimens that are not exposed to water environment. The fatigue strength due to water uptake was about eleven percent which was independent of stress ratio. Then, the full shapes of the constant fatigue life (CFL) diagrams for the laminates in dry and wet environments were identified using the fatigue test data obtained at different stress ratios, which are characterized by asymmetry, nonlinearity and gradual change in shape. Finally, the anisomorphic CFL diagram approach for composites, which was developed in an earlier study, was tested on the dry and wet CFRP laminates. It is demonstrated that the anisomorphic CFL diagram approach succeeds in adequately predicting the CFL diagrams for the quasi-isotropic laminate in wet as dry environment.