Characterization of Fatigue Behavior of Non-Crimp Fabric Composites

Abstract

Experimental characterization was performed to investigate the fatigue life of non-crimp fabric (NCF) at stress ratio 0.1 and frequency 1Hz. Three types of NCFs were investigated: carbon fiber biaxial [0/+45], glass fiber unidirectional and triaxial with balanced [0/+45/-45] and unbalanced [0/+25/-45] configurations. Effect of two stitching patterns (tricot and chain tricot), areal weights (thin and thick), and layups (symmetric and double symmetric) on fatigue life of carbon fiber biaxial NCF were identified. For glass fiber, the effect of seven different stabilization patterns on unidirectional NCF and the effect of angle on balanced and unbalanced triaxial NCF were also examined. The static and fatigue properties are presented with 95% confidence calculated by ASTM E739. A significant difference caused by stitching patterns, areal weights, and layups has been found in the static and fatigue properties of biaxial carbon fiber. In glass fiber unidirectional NCF, lower fiber and bundle volume fractions resulted in low static strength and stiffness but higher fatigue life. The balanced triaxial laminate has also been found with lower static properties but higher fatigue life when compared with an unbalanced triaxial laminate.