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

Abstract

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.

ZnO Nanostructured Interphase for Multifunctional and Lightweight Glass Fiber Reinforced Composite Materials under Various Loading Conditions

“…For instance, numerous external sensors can now be substituted by embedded sensing of various forms inside composite structures, such as capacitive, 1,2 piezoresistive, 3 and piezoelectric. 4,5 Other functions that have been successfully integrated into composite structures include selfhealing, 6 thermal protection, 7 electromagnetic shielding, 8 and damage monitoring. 5,9 However, the formation of composite structures that exhibit tailored strength across loading rate is a novel multifunctionality that has yet to be realized in fiberglass composites.…”

“…4,5 Other functions that have been successfully integrated into composite structures include selfhealing, 6 thermal protection, 7 electromagnetic shielding, 8 and damage monitoring. 5,9 However, the formation of composite structures that exhibit tailored strength across loading rate is a novel multifunctionality that has yet to be realized in fiberglass composites. Fiberglass composite structures are often applied to naval and aerospace applications, such as engine nacelles, wings, and fuselages, as well as re-entry vehicles that require high structural performance to withstand aerodynamic loads and support other body forces during operation.…”

“…As fiber reinforced composites continue to grow and find use in an increasing number of applications, so is the need to further expand the multifunctionality of these materials to improve system designs and achieve greater reduction in weight and cost. For instance, numerous external sensors can now be substituted by embedded sensing of various forms inside composite structures, such as capacitive, , piezoresistive, and piezoelectric. , Other functions that have been successfully integrated into composite structures include self-healing, thermal protection, electromagnetic shielding, and damage monitoring. , However, the formation of composite structures that exhibit tailored strength across loading rate is a novel multifunctionality that has yet to be realized in fiberglass composites. Fiberglass composite structures are often applied to naval and aerospace applications, such as engine nacelles, wings, and fuselages, as well as re-entry vehicles that require high structural performance to withstand aerodynamic loads and support other body forces during operation.…”

Nanostructured ZnO Interphase for Carbon Fiber Reinforced Composites with Strain Rate Tailored Interfacial Strength

“…[43][44][45] The piezoelectric nature of these nanowires improve the fiber reinforced composites' functionality, allowing it to harvest energy from its surroundings and detect damage during operation. [6,46] Galan et al [47] reported a 228% improvement in IFSS of carbon fiber reinforced polymers at quasi-static conditions, when the ZnO nanowires with optimized aspect ratio were introduced onto the surface of the carbon fibers. It was reported that IFSS increased near-linearly with an increase in both the length and diameter of the nanowires.…”

Editorial for the Special Issue on Advanced Fiber-Reinforced Polymer Composites

“…More recently, researchers have developed methods to integrate non-structural functions in the composites. The new functionalities include energy harvesting, [1,2] force sensing, [3,4] damage detection, [5,6], ballistic impact resistance, [7,8] electromagnetic shielding, [9,10] UV resistance, [11,12], and so forth. In advanced composite materials, the reinforcing fibers can be selected from various synthetic or natural fibers in the form of short fibers, continuous tows, or woven fabrics.…”