Early-Stage Damage Detection in Advanced Multifunctional Aerospace Composites Using Embedded Carbon Nanotubes and Flocked Carbon Fibers

Abstract

Early-stage damage detection could provide better reliability and performance and a longer lifetime of materials while reducing maintenance time of a variety of structures and systems. We investigate the early-stage damage formation and damage evolution in advanced multi-functional laminated aerospace composites embedded with a very small amount of carbon nanotubes (CNTs) in the matrix material and short carbon fibers along the Z-direction to reinforce the interlaminar interfaces. The three-dimensional (3-D) conductive network formed by the CNTs and the flocked carbon fibers allows for sensitive in-situ damage detection in materials in addition to providing improved mechanical properties such as superior fracture toughness for damage tolerance. We optimize several parameters such as fiber length, diameter, and density to generate an effective 3-D electrical conductive network, and characterize the responses of these composites under mechanical loading to investigate damage formation and evolution, advancing science and technology towards superior damage-tolerant and zero-maintenance structural materials.

Characterizing the Effect of Transverse Strain on Carbon Nanotube Based Sensing Skins for Structural Health Monitoring

“…This has facilitated tremendous advancement in developing nanostructured hierarchical composites and textiles. Specifically, researchers have widely used carbon nanotubes due to their extraordinary properties for applications such as improving the mechanical properties of composites [3][4][5], self-sensing composites [6][7][8], energy harvesting composites [9,10], wearable strain sensors and flexible pressure sensors [11][12][13][14][15], sensing skin for structural health monitoring [16][17][18] and fatigue crack monitoring [19,20] and damage monitoring of joints [21].…”