In Situ Damage Detection for Fiber‐Reinforced Composites Using Integrated Zinc Oxide Nanowires

• Published in: Advanced functional materials 2018-08, Vol.28 (35), p.n/a
• Main Authors: Groo, LoriAnne, Inman, Daniel J., Sodano, Henry A.
• Format: Article
• Language: English
• Subjects: Carbon fibers; Catastrophic failure analysis; Damage detection; Electric potential; Electrical measurement; Energy harvesting; fiber‐reinforced composites; Materials science; Nanowires; Particulate composites; Piezoelectricity; Reinforcing fibers; self‐sensing; Structural damage; Structural health monitoring; Vibration monitoring; voltage emission; Zinc oxide; Zinc oxides; ZnO nanowires
• ISSN: 1616-301X; 1616-3028
• DOI: 10.1002/adfm.201802846

A multifunction material that increases strength is capable of harvesting energy from ambient vibration and acts as a structural health monitoring system is presented. Current in situ damage detection of fiber‐reinforced composites typically uses methods which require external sensors, precise initial measurements for each component under evaluation, or input current to the structure. To overcome these limitations, this work utilizes a multifunctional interphase of piezoelectric zinc oxide nanowires integrated into fiber‐reinforced composites to provide an in situ ability to sense damage. The nanowires are grown onto insulating reinforcing fibers which are sandwiched between carbon fiber electrodes, thus fully integrating the sensing element into the fiber‐reinforced composite. The fully distributed nanowire interphase proves capable of detecting multiple damage modes using passive voltage measurements as demonstrated during multiple loading configurations. This work also analyzes voltage emissions corresponding to damage to provide signal characteristics corresponding to the damage state of the specimen to indicate damage progression and the approach of catastrophic failure. The result of this work is thus a multifunctional structural material with damage detection capabilities. The principles investigated in this work can also be extended to alternative structural composites containing integrated piezoelectric materials in the form of nanoparticles, nanowires, or films. A multifunctional interphase of piezoelectric ZnO nanowires is utilized for damage sensing in a fiber‐reinforced composite material. Damage within the test specimen containing ZnO is shown to result in a spontaneous charge separation that could be detected via voltage output. The voltage emission is thus used to indicate the occurrence of damage, while the accumulation of such events indicates damage progression.