Investigation Of Quasi-Static And Low-Velocity Impact Responses Of 12k Im7/5320-1 Laminates Toughened With Vertically Aligned Carbon Nanotubes

Composite structures have become an attractive material selection for researchers and industries such as in aerospace, automotive, naval, and green energy due to their high strength to weight ratios and custom tailor ability through material selection. With the increasing selection of composites as the material of choice for most of these industries understanding their failure mechanisms is imperative to the continued success and implementation of these structures. This failure mostly originating from the resin-rich regions which bond the adjacent ply-to-ply surfaces together which have much weaker mechanical properties than those of the high modulus fibers. In this report commercially available Vertically Aligned Carbon Nanotubes (VACNTs) were purchased and implemented within those resin-rich regions to improve the strength and damage tolerance of composite materials. Their morphological parameters were chosen after a thorough investigation of their length and diameters yielded adverse strengthening effects on composites reinforced by them. Roll-to-roll manufacturing was used to transfer to VACNTs from the large wafers of which they were grown on to the fibers themselves using a combination of heat and pressure. This process has large commercial viability which is a rare commodity in interlaminar reinforcements with the possibility of a high efficiency rate into large batch industrial processing. An in-depth analysis of the microstructure of both pre- and post-tested samples through Scanning Electron Microscopy (SEM), Ultrasonic C-scans, and Micro CT scans were conducted to characterize the structural integrity and the strengthening effects of the VACNTs on unidirectional Carbon Fiber Reinforced Polymer Matrix Composites (CFRPs). The characterized microstructures along with the material performance of the composites yielded valuable insights into how effective the VACNTs were in improving the performance of composites reinforced with them. To the authorâ??s knowledge this is the first study of its kind on this fiber/matrix combination.