Effect of Fiber Cutting Angle on The Fatigue Behavior of Open-Holed CFRP Laminates with Initially Cut Fibers

抄録

This study investigated the effects of fiber cutting angle on the fatigue behavior of open-holed carbon fiberreinforced plastic (CFRP) laminates with initially cut fibers (ICFs). Three kinds of fiber cutting angles (θ= 22.5, 45, and 90°) were applied to two types of quasi-isotropic ICF laminates: one was fabricated using autoclave (ICF-A) and the other was fabricated using press molding (ICF-P). First, fatigue tests were conducted to obtain S (maximum stress)-N (the number of cycles to failure) curves in order to reveal fatigue strength. The fatigue tests of one specimen for each configuration were interrupted at three prescribed numbers of cycles to observe damage progress. Finally, a semi-empirical equation was proposed to predict delamination area just before the final failure against normalized applied stress. It is found from the experiment result that the fatigue strength in both laminates is the highest when the θ is the smallest (22.5°) although the static strength is the highest when the θ is 90°.In contrast, both laminates with the biggest θ(90°) exhibit the greatest delamination growth around the hole by cyclic loading.