Study on Mechanical Properties of Carbon Nanotube Reinforced Composites

In this study, carbon fiber composite laminates were modified by carbon nanotube films. In-plane and out-of-plane compression tests were carried out in a wide strain rate range (10(−3)–10(3)/s). Results display that the out-of-plane compressive properties are improved by CNT interlaminar toughening because CNT can hinder the propagation of interlayer cracks; however, the dynamic in-plane compression performance is decreased due to the lack of resin in CNT film that leads to delamination inside of CNT film in advance. To optimize the material preparation process, two methods were used to prepare the mode I fracture test: (a) curing the prepreg by autoclave process; and (b) curing of resin preform by vacuum resin-transmitted molding (VARTM). Results showed that CNT prolonged the crack propagation path and improved the interlaminar fracture properties when the preform was infiltrated with resin and cured by VARTM. In addition, it was found that the interlaminar thickness was almost linear with the number of CNT layers.