|phmc_10_019.pdf||398.69 KB||August 20, 2010 - 5:54am|
Composites present additional challenges for inspection due to their heterogeneity and anisotropy, and since damage often occurs beneath their surface. Currently successful laboratory non-destructive methods, such as X-ray and C-scans, are impractical for inspection of large integrated structures. It is clear that new approaches for inspection of composites need to be developed. During the present research, multiple carbon nanotube (CNT) based NDE & SHM techniques were investigated to resolve these issues. Aligned CNTs offer excellent mechanical toughness improvements for traditional composite laminates, and additionally enable multifunctional capabilities through piezoresistive properties and greatly enhanced electrical and thermal conductivity. This paper presents results for multiple CNT-enhanced laminates that were electroded using direct-write techniques and subject to impact damage. A resistive-based method was used to create a detailed damage map of the effected zone. Finally, demonstrations are also described for multiple alternative CNT-based NDE approaches that were explored.