STRAIN RATE-DEPENDENT CHARACTERIZATION OF THE IN-PLANE SHEAR RESPONSE OF A UNIDIRECTIONAL NON-CRIMP FABRIC CARBON FIBER/SNAP-CURE EPOXY COMPOSITE
The dynamic in-plane shear stress-strain response of a unidirectional non- crimp fabric carbon fiber/snap-cure epoxy composite was studied by subjecting 30° and 45° off-axis specimens to compression loading at high strain rates. Tests were performed using a compression split-Hopkinson pressure bar apparatus where an approximate axial strain rate of 305 s-1 was achieved. Images of the deformed specimen surfaces were captured with high-speed cameras and digital image correlation used to obtain a strain map. Pulse shaping was performed using a copper pulse shaper to achieve dynamic equilibrium during the high-rate tests. The results demonstrated that the in-plane shear yield stress and strength increased by 53% and 68%, respectively, when the strain rate increased from quasi-static to 305 s-1.