Application Cases

Experiment Name: Aircraft Wing De-icing Method Based on Piezoelectric Actuators

Experimental Principle:
This study employs lightweight piezoelectric actuators that utilize the inverse piezoelectric effect of piezoelectric crystals. By applying a specific electric field to the piezoelectric crystals, structural vibrations are induced. Appropriate frequencies and vibration modes are selected to achieve deformation and generate shear stress that matches the adhesive force between the wing and the ice layer, thereby achieving de-icing. Aluminum plates were used for modeling and analysis in the study, with a finite element model employed to predict their resonant frequencies and shear stress. Using a Doppler laser vibrometer, the multi-order vibration modes of the structure were observed, and suitable frequencies and modes were selected for experiments on ice-coated models.

Testing Equipment:
Signal generator, ATA-1372A broadband amplifier, Doppler laser vibrometer and its control system, piezoelectric ceramics, aluminum plates.

Experimental Procedure:
First, vibration testing was conducted on a rectangular plate with fixed boundaries on all four sides. The Doppler laser displacement vibration measurement system was controlled by a computer, with the control box generating a 0–2 kHz frequency sweep signal. This signal was amplified by the ATA-1372A broadband power amplifier. As the voltage required for the vibration test was not very high, the signal was amplified to a peak-to-peak voltage of 50 V to drive the piezoelectric patches on the rectangular plate, inducing its vibration. The Doppler laser vibrometer collected information such as vibration modes, displacement, and velocity, which were processed by software and presented graphically. The out-of-plane vibrations, which are crucial for de-icing, were analyzed, and the driving frequency corresponding to larger displacements was selected as the operating frequency for the piezoelectric patches. The experimental block diagram is shown in Figure 1.

Figure 1: Experimental Block Diagram

The Doppler laser vibrometer can obtain the corresponding vibration modes at these resonant frequencies. Comparing the modal shapes obtained from the laser vibrometer with those from ANSYS simulations, it was observed that the second-order mode, being antisymmetric, could not be excited due to the phase difference between the two symmetrically placed piezoelectric patches, which caused amplitude cancellation. Comparing the first few modal shapes obtained from the vibration test with those from ANSYS simulations, it can be seen that, except for the inability to identify the second-order mode due to amplitude cancellation caused by the phase difference of the piezoelectric patches, the resonant modes obtained from the experiment matched well with the simulation results. Observing the maximum displacements of each modal shape obtained from the Doppler laser vibrometer, it was found that the maximum amplitudes were relatively large at 83.4 Hz, 213.8 Hz, and 233.4 Hz. The maximum displacement measured by the Doppler laser vibrometer under a 50 V peak-to-peak voltage is shown in Figure 2.

Figure 2: Maximum Displacement at the First Six Resonant Frequencies

The experiment identified the frequency points with larger amplitudes in the 0–2 kHz sweep range obtained from the Doppler laser vibrometer. Based on the vibration modes, these frequency points were determined to be the natural frequencies of the thin plate, corresponding to their respective vibration modes. These resonant frequencies induced relatively large maximum displacements. These frequencies were selected as the operating frequencies for the piezoelectric patches for the subsequent de-icing experiments.

An aluminum plate with dimensions of 0.40 m × 0.24 m × 0.001 m was constructed using hard aluminum 12, with all four sides fixed. The piezoelectric patches had dimensions of 0.3 m × 0.3 m × 0.0002 m and were made of PZT5. The patch attachment method is shown in Figure 3. The aluminum plate was placed in a low-temperature refrigerator with a temperature range of -35°C to 20°C and a control accuracy of 0.1°C.

Figure 3: Patch Arrangement on a Rectangular Plate with Fixed Boundaries on All Four Sides

Experimental Results:
By exciting different vibration modes using the tested frequency bands, it was observed that the de-icing effect was significant at 233 Hz. From the previous vibration tests, it was evident that this frequency primarily excited the third-order mode. Although other frequencies also showed relatively large vibration displacements in the vibration tests, only the third-order mode achieved de-icing. This is because the third-order mode is a resonant mode. This result aligns closely with the simulation conclusion that only the third-order mode can achieve de-icing.

Figure 4: De-icing Effect of the Third-Order Mode

Figure: Specifications of the ATA-1372 Broadband Amplifier

The experimental materials in this article were compiled and released by Xi'an Aigtek Electronics. For more experimental solutions, please continue to follow the Aigtek official website.