Self-sensing piezoelectric composites via generation and reception of ultrasonic guided waves

This article presents a novel family of intelligent piezoelectric
composite structures. Unlike conventional self-sensing composites limited
to passive monitoring and constrained by low actuation capacity, this
study puts forward a novel structure-actuator-sensor integration that
combines with Electro-Mechanical Impedance Spectroscopy (EMIS) active
sensing, while preserving its mechanical performances. The structure is
formed by distributing Pb(Zr0.52Ti0.48)O3 piezo powder and epoxy as the
active component to impregnate glass fibers, enabling every inch of the
material to function as both an actuator and a sensor. To develop an
insight into the EMIS method combined with piezoelectric composites,
coupled-field Finite Element (FE) models are constructed for verifying the
feasibility of the EMIS for damage detection. A Root Mean Square Deviation
(RMSD) damage metric is subsequently utilized to determine the position of
the structural damage. It is found that RMSD metric indicates substantial
deviations in the impedance spectrum near the damage site, while spectrums
at distant locations show minimal change, rendering a high resolution
spatial diagnostic capability. Furthermore, piezoelectric composite plate
specimens are crafted to achieve high degree of sensitivity and
reliability through material parameter optimization and process
refinement. A series of mechanical performance comparative experiments are
conducted to verify the load-bearing competency of the composites.
Finally, experimental validation is performed, demonstrating the
performance of the EMIS active sensing for the damage localization in the
proposed composite structures. The composite system possesses the prowess
for achieving self-awareness through such actuator-sensor-structure
integration, which could be potentially utilized in the next generation of
wing and fuselage structures in aviation industry, high pressure vessels
for hydrogen storage, and smart composite pipelines for transporting gas
and petroleum. The paper finishes with summary, concluding remarks, and
future work.