Application Cases

Experiment Name: Application of Power Amplifier in Detection of Hole Crack Defects in CFRP Plates Using Giant Magnetostrictive Transducers

Research Direction: Nondestructive Testing

Test Objective: To verify the effectiveness of magnetostrictive transducers in identifying hole defects in CFRP plates.

Testing Equipment: ATA-2021H high-voltage amplifier, signal source, oscilloscope, transducer, etc.

Experimental Content: A frequency sweep signal was applied to the transducer to determine its optimal operating frequency band. Excitation signals were then applied to the transducer to detect hole defects in CFRP using ultrasonic guided waves, followed by signal processing to locate the defect positions.

Experimental Procedure:
The test plate was made of CFRP, with a side length of 500 mm and a thickness of 2 mm. Excitation waveforms were generated by a signal generator, amplified by a power amplifier, and transmitted as high-energy ultrasonic signals via the magnetostrictive transducer. PZT-5 square patches were used for signal acquisition, and the defect information contained in the guided wave signals was analyzed.

Experimental Results:

(1) Frequency sweeping allows rapid testing of the frequency characteristics of the component. By applying a continuously varying frequency signal to the transducer, the response characteristics at different frequencies were obtained. Since the operating frequency of the giant magnetostrictive material does not exceed 100 kHz, the sweep frequency range was set to 40–100 kHz. The response signal amplitude at the excitation end increased linearly with frequency. After propagating through the composite plate, the sweep signal reached the receiving end. As shown in the figure, at frequencies of 70, 80, and 92 kHz, the signal amplitude exhibited local peaks, representing the relatively optimal excitation frequencies for the transducer.

(2) The final defect cloud map was obtained by applying a short-time Fourier transform to the signals.

Figure: ATA-2021B High-Voltage Amplifier Specifications and Parameters