Experimental study on the charpy impact failure of 3D integrated woven spacer composite at room and liquid nitrogen temperature

The charpy impact experiments on the 3D integrated woven spacer composites with six types of core heights are performed at room and liquid nitrogen temperatures (as low as −196 °C). Macro-fracture morphology and SEM micrographs are examined to understand the deformation and failure mechanism. The results show that the impact energy increase with the increase of the core height at both room and liquid nitrogen temperatures. Meanwhile, the impact properties at liquid nitrogen temperature have been improved significantly than that at room temperature. Moreover, at room temperature, the penetration fracture of the face sheets, the tearing and pulling out of the core fibers as well as the cracking of the matrix is the main damage and failure patterns. However, at liquid nitrogen temperature, the matrix crushing dominates the failure. Less fibers fracture and brittle fracture feature becomes more obvious. In addition, with the increase of the core heights, the damage of composites has been reduced significantly at room and liquid nitrogen temperatures.