A Sensitivity Study of Different Actuators for the Electromechanical Impedance Method in 3D-Printed Material

The electromechanical impedance (EMI) technique assesses the health of structures in the frequency domain using piezo-actuators. EMI employs a high-frequency range and is a promising method to be used for the evaluation of lightweight structures. This study focuses on understanding the comparative sensitivity of different actuators to damage presence in additively manufactured (AM) polymer structures. An acrylonitrile butadiene styrene (ABS) plate printed with horizontal layup was used for the investigation, where 2 PZT and 1MFC actuators were fixed on the surface. Initially, damage was simulated by moving small magnets away from the actuators on both sides of the plate. Further, an impact damage was created at the center of the plate to compare the damage sensitivity of the three actuators. While both actuator types have shown a good damage sensitivity and coverage, a better sensitivity was observed in the case of the MFC actuator, as compared to PZTs. The attained damage index results of impedance and conductance are promising for the assessment of AM polymer structures.