Advancing measurement of zero-group-velocity Lamb waves using PVDF-TrFE transducers: first data and application to in situ health monitoring of multilayer bonded structures. (July 2023)

• Record Type: Journal Article
• Authors: Liu, Qijian; Li, Yehai; Guan, Ruiqi; Yan, Jiajia; Liu, Menglong; Luo, Guojie; Su, Zhongqing; Qing, Xinlin; Wang, Kai
• Is Part Of: Structural health monitoring. Volume 22:Number 4(2023)
• Page Start: 2641
• Page End: 2650
• Publication Date: 2023-07
• Subjects: Zero-group-velocity waves -- PVDF-TrFE transducers -- in situ health monitoring -- multilayer bonded structure -- disbond defects; Structural health monitoring -- Periodicals; Structural stability -- Periodicals; Strength of materials -- Periodicals; Nondestructive testing -- Periodicals; Constructions -- Stabilité -- Périodiques; Résistance des matériaux -- Périodiques; Contrôle non destructif -- Périodiques; Electronic journals; 624.17
• DOI: 10.1177/14759217221126812
• Languages: English
• ISSNs: 1475-9217

Abstract

Driven by the rapid advancement in manufacturing technologies, engineering structures with complex geometries are increasingly applied in various industries, posing challenges to the applicability and adaptability of existing structural health monitoring methods based on guided ultrasonic waves. To fulfill the characterization of defects in complex structures, a novel approach featuring a conjunction of zero-group-velocity (ZGV) Lamb waves and polarized poly(vinylidenefluoride-co-trifluoroethylene) (PVDF-TrFE) transducers is proposed. In this approach, the PVDF-TrFE solvent is deposited and in situ polarized on the structure surface to form thin and flexible coatings, with which the ZGV waves can be excited efficiently and measured reliably. On this basis, the defect can be characterized by investigating the defect-induced alteration in ZGV wave features. In experimental validations, disbond defects in multilayer bonded structures are evaluated using the ZGV waves measured with fabricated PVDF-TrFE transducers. For the first time, the ZGV waves are measured in a contact and in situ manner. Compared with conventional noncontact measurement of ZGV waves, the proposed approach features a remarkably improved reliability, convenience for narrowband excitation, immunity to measurement uncertainty and capability of in situ monitoring. The proposed approach can advance the ZGV wave-based methods toward the in situ health monitoring and enable the defect evaluation in emerging complex structures.