Integration of piezoelectric transducers (PZT and PVDF) within polymer-matrix composites for structural health monitoring applications: new success and challenges
Résumé
This article investigates the interest of using in-situ piezoelectric (PZT
and PVDF) disks to perform real-time Structural Health Monitoring
(SHM) of glass fiber-reinforced polymer composites submitted to various
tensile loadings. The goal is to evaluate the working range and
SHM potential of such embedded transducers for relatively simple
mechanical loadings, with the long-term aim of using them to monitor
complete 3D structures submitted to more complex loadings. SHM is
performed acquiring the electrical capacitance variation of the
embedded transducers. To study the potential links between the insitu
capacitance signal and the global response of the loaded host
specimens, a multi-instrumentation composed of external
Nondestructive Testing techniques was implemented on the surfaces
of the specimens to search for multi-physical couplings between these
external measurements and the capacitance curves. Results confirmed
the non-intrusiveness of the embedded transducers, and allowed
estimating their working domain. PZT capacitance signal follows well
the mechanical loadings, but the piezoceramic transducer gets
damaged after a determined relatively low strain level due to its
brittleness. The limits of this working domain are extended by using
a stretchable PolyVinylidene Fluoride (PVDF) polymer transducer,
allowing this one to perform in-situ and real-time SHM of its host
tensile specimens until failure.