抄録
Effects of the difference in stacking sequence on the fatigue strengths of cross-ply CFRP laminates have been studied. Fatigue tests are performed at room temperature on three kinds of non-woven cross-ply laminates, A:[90/0]_<3s>, B:[90_3/0_3]_s, and C:[0_3/90_3]_s, respectively, using unnotched and center-holed (CH) coupon specimens are used By comparing S-N diagrams and fatigue damage development, the stacking sequence dependence of notched fatigue behavior is elucidated. An attempt is also made to develop an engineering method for predicting the notched fatigue strengths of the CFRP laminates. For each of the three kinds of laminates, the fatigue strengths of the notched specimens are lower than those of the unnotched specimens, and they become smaller with increasing notch length. This feature is more appreciable in the type A laminate, because of the highest notch sensitivity. Finally, a fatigue model in which the fatigue exponent is defined as a function of notch size is suggested, and it is demonstrated that the fatigue model succeeds in describing adequately the fatigue strengths of the notched cross-ply laminates.
