Design and Characterization of the CLoVER Transducer

for Structural Health Monitoring

Student :

Sponsor :

Ken Salas [Thesis][Profile]

AFOSR

Summary:

Structural health monitoring (SHM) is an integral part of damage prognosis systems. Guided wave (GW) testing methods are attractive for this application due to the ability of GWs to travel over long distances with little attenuation and their sensitivity to different damage types. The Composite Long-range Variable-direction Emitting Radar (CLoVER) transducer was developed as an alternative concept for efficient damage interrogation and GW excitation in GW based SHM systems. The major contributions to date are:

  • Designed and fabricated a new GW transducer, with wedge-shaped sections arranged in a circular array

  • The novel geometry produces larger actuation amplitudes than traditional ring configurations, and can interrogate a complete 360 degree range from a central location.

  • Experimentally simulated the proposed damage interrogation approach using concentrated masses to represent damage. CLoVER sectors were successful in identifying damage primarily within their azimuthal range, signifying efficient use of excitation energy.

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Damage interrogation approach used with CLoVER transducers.

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Out-of-plane displacement field for A0 mode at a frequency thickness product of 208 kHz-mm.

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Sample interdigitated electrode pattern used in CLoVER transducers.

 

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Strain performance comparison among different piezocomposite transducers