疲労負荷を受ける擬似等方性CFRP積層板のトランスバースクラック発生における応力比の影響

抄録

Carbon fiber reinforced plastic (CFRP) laminates are expected to be expanded as structural members due to their excellent mechanical properties. It is essential to evaluate theirfatigue propertiesto ensure long-term reliability and durability. The fatigue damage growth behavior of CFRP laminates differs greatly depending on the load condition, laminate configuration and dimensions. In particular, it is necessary to predict the initiation of transversal crack since they are become a starting point of fiber breakage and delamination. In this study, the fatigue tests were performed using quasi-isotropic CFRP laminates with stress ratios of R = 0.1 and -1. Then, the fatigue life to the transversal crack initiation was predicted using a modified Walker model. In addition, the results were compared with those of cross-ply CFRP laminates previously performed by the authors. As a result, it was found that if the stress applied to the 90° layers is a tension-tensile condition, the initiation of transverse cracks can be predicted regardless of the laminate configuration and the stress ratio.