Power amplifier based on piezoelectric active sensing technology

Experiment Name: Application of Power Amplifier Health Monitoring Method Based on Piezoelectric Active Sensing Technology

Purpose:

The time inversion method of piezoelectric ceramic sensors is verified to be able to effectively monitor the connection status and stress state of the bolt ball joint connection area.

Experimental equipment: power amplifier ATA-2022H, piezoelectric ceramics, bolt ball, sleeve, data acquisition card, computer.

Experimental content:

This experiment will use piezoelectric ceramic sensors to test the health status monitoring method of the bolt ball node connection area based on time reversal technology through model tests. The peak value of the time reversal focused signal is only related to the transfer function of the propagation path that the signal passes through when it is transmitted on the structure. When the bolts inside the bolt ball node are damaged or not installed in place (damaged state), it is equivalent to a change in the transfer function, and the peak value of the focused signal will also change.

Experimental process:

During the test, the signal is amplified by the power amplifier to excite the piezoelectric ceramic sensor. The signal is transmitted to the rod through the bolt ball and sleeve. The PZT2 sensor on the rod receives the signal and transmits it back to the data acquisition card. The laptop workstation uses LabView for time reversal processing. The time-reversed signal is then applied to the PZT2 sensor on the rod as an excitation signal, and the reversed signal is transmitted to the bolt ball through the rod and sleeve to form a focus signal with a peak value. Finally, the PZT1 on the central bolt ball node receives the focus signal, and the laptop displays the processed signal data.

Test device based on time reversal method

Time reversal analysis signal transfer diagram

Experimental results:

Focus signal peak diagram under noise-free and noise conditions

Focus peak value of noise-free working condition, focus peak value of noise working condition, and rod axial force change diagram

Experimental conclusion:

In summary, regardless of whether there is noise or not, the bolt ball joint connection area based on the time inversion method has the same monitoring results, indicating that the method has strong noise robustness, that is, noise resistance. During the installation and use of actual projects, it is inevitable that it will be affected by factors such as wind load, construction load, and monitoring test error. The good noise resistance of time inversion will ensure that this method is better applicable to actual projects.