Real-time electrical impedance resonance shift of piezoelectric sensor for detection of damage in honeycomb core sandwich structures

• Mechanical impedance resonance shift was induced by moving a proof mass on top of the structure.
• Mechanical impedance resonance shift changes due to difference in cross sectional area of structure.
• This change can be reflected by measuring the real-time electrical impedance of PZT sensor.
• The proposed method is simple and accurate because no baseline is required to identify the defect.

A simple and low cost method for structural health monitoring of honeycomb composite shaped in cantilever beam was reported. A lead zirconate titanate (PZT) sensor was attached to the cantilever beam and vibrated resonantly. The real-time imaginary part of electrical impedance of PZT sensor was measured to correlate with the induced mechanical impedance resonance shift of cantilever beam when a proof mass was moved on top of cantilever beam. When a defect was present, it caused a disrupted change of imaginary part of electrical impedance. Such detection is real-time so that no baseline is required to identify the defect accurately.