Self-sensing piezoelectric composite structures leveraging dispersed electro–mechanical impedance spectral measurements

Abstract This paper presents a new piezoelectric composite material integrating with dispersed electro–mechanical impedance (EMI) measurements for achieving structural self-awareness. The composite material is meticulously designed and fabricated through homogeneous distribution of piezo-ceramic particulates across an epoxy-based polymeric medium, followed by impregnation into glass fibers. The influence of piezo particles on the mechanical properties of the composite material is systematically investigated through tensile tests. To gain an insight into the EMI active self-sensing integrated with the functional composite structure, finite element modeling is conducted. Subsequently, a root mean square deviation (RMSD) algorithm is adopted for evaluating impedance signal deviations for identifying the damage location. It is found that the RMSD metric indicates substantial deviations in the impedance spectrum near the damage site, while spectra at distant locations show minimal change. Dense electrodes can form dispersed sensing neurons, rendering a high resolution spatial diagnostic capability. Finally, experimental validation is performed, demonstrating the performance of the EMI active sensing for damage diagnostics.