title: Applications of a nanocomposite-inspired in-situ broadband ultrasonic sensor to acousto-ultrasonics-based passive and active structural health monitoring.
abstract: A novel nanocomposite-inspired in-situ broadband ultrasonic sensor previously developed, with carbon black as the nanofiller and polyvinylidene fluoride as the matrix, was networked for acousto-ultrasonic wave-based passive and active structural health monitoring (SHM). Being lightweight and small, this kind of sensor was proven to be capable of perceiving strain perturbation in virtue of the tunneling effect in the formed nanofiller conductive network when acousto-ultrasonic waves traverse the sensor. Proof-of-concept validation was implemented, to examine the sensor performance in responding to acousto-ultrasonic waves in a broad frequency regime: from acoustic emission (AE) of lower frequencies to guided ultrasonic waves (GUWs) of higher frequencies. Results have demonstrated the high fidelity, ultrafast response and high sensitivity of the sensor to acousto-ultrasonic waves up to 400kHz yet with an ultra-low magnitude (of the order of micro-strain). The sensor is proven to possess sensitivity and accuracy comparable with commercial piezoelectric ultrasonic transducers, whereas with greater flexibility in accommodating curved structural surfaces. Application paradigms of using the sensor for damage evaluation have spotlighted the capability of the sensor in compromising "sensing cost" with "sensing effectiveness" for passive AE- or active GUW-based SHM.
authors.affiliation: Department of Mechanical Engineering, The Hong Kong Polytechnic University, Kowloon, Hong Kong Special Administrative Region.
authors.forename: Menglong
authors.initials: M
authors.lastname: Liu
authors.affiliation: Department of Mechanical Engineering, The Hong Kong Polytechnic University, Kowloon, Hong Kong Special Administrative Region; CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, The National Center for Nanoscience and Technology, Beijing 100190, PR China; University of Chinese Academy of Science, Beijing 100049, PR China.
authors.forename: Zhihui
authors.initials: Z
authors.lastname: Zeng
authors.affiliation: School of Aeronautics and Astronautics, Faculty of Vehicle Engineering and Mechanics, State Key Laboratory of Structural Analysis for Industrial Equipment, Dalian University of Technology, Dalian 116024, PR China.
authors.forename: Hao
authors.initials: H
authors.lastname: Xu
authors.affiliation: Department of Mechanical Engineering, The Hong Kong Polytechnic University, Kowloon, Hong Kong Special Administrative Region.
authors.forename: Yaozhong
authors.initials: Y
authors.lastname: Liao
authors.affiliation: Department of Mechanical Engineering, The Hong Kong Polytechnic University, Kowloon, Hong Kong Special Administrative Region.
authors.forename: Limin
authors.initials: L
authors.lastname: Zhou
authors.affiliation: CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, The National Center for Nanoscience and Technology, Beijing 100190, PR China.
authors.forename: Zhong
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: Department of Mechanical Engineering, The Hong Kong Polytechnic University, Kowloon, Hong Kong Special Administrative Region. Electronic address: Zhongqing.Su@polyu.edu.hk.
authors.forename: Zhongqing
authors.initials: Z
authors.lastname: Su
mesh_terms: D002138:Calibration; D004867:Equipment Design; D008855:Microscopy, Electron, Scanning; D008991:Monitoring, Physiologic / Q000295:instrumentation*; D053761:Nanocomposites / Q000737:chemistry*; D011145:Polyvinyls / Q000737:chemistry; D012815:Signal Processing, Computer-Assisted; D053260:Soot / Q000737:chemistry; D014159:Transducers; D014465:Ultrasonics; D005465:Fluorocarbon Polymers
chemical_list: D011145:Polyvinyls; D053260:Soot; C024865:polyvinylidene fluoride; D005465:Fluorocarbon Polymers
keywords: Acoustic emission; Acousto-ultrasonics; Guided ultrasonic waves; Nanocomposite sensor; Structural health monitoring; Ultrasonic sensor