Application Cases

Experiment Name: Application of High-Voltage Power Amplifier in Research on Hydrochloric Acid Corrosion and Simulated Damage Monitoring of Aluminum Plate Structures

Research Direction: Nondestructive Testing

Test Objective: Transducers excite Lamb wave signals within the structure. When Lamb waves encounter damage or boundaries during propagation, scattering and reflection phenomena occur. Based on these phenomena, damage localization algorithms can be designed.

Testing Equipment: ATA-4052 High-Voltage Power Amplifier, Signal Generator, Oscilloscope for Monitoring Input Signals, Prototype of Flexible Valve Piezoelectric Pump, Beaker for Containing Fluid, Electronic Balance for Mass Measurement.

Experimental Procedure: USB data cables are used to establish USB communication connections between the programmable multi-channel charge amplifier (referred to as programmable amplifier) and the system controller (Signal Flow 1). The system controller controls the arbitrary waveform generation card to generate a five-peak modulated sinusoidal signal with an amplitude of 4V and a center frequency of 50 kHz, which is then output to the power amplifier (Signal Flow 2). This voltage signal undergoes 20× voltage amplification via the power amplifier and is output to the programmable amplifier (Signal Flow 3). The programmable amplifier selects appropriate piezoelectric elements as actuators to excite Lamb waves within the structure and selects appropriate piezoelectric elements as sensors to detect data within the structure.

Experimental Results: Figures (a) and (b) respectively show the baseline signals and damage signals when damage is close to the sensing path (1B-2B) and when damage is far from the sensing path (1B-1D). From Figure (a), it can be observed that when damage is close to the sensing path, there are significant differences in amplitude between the baseline signal and the damage signal, further reflected in the uncorrelation coefficient defined by standard deviation. Therefore, the monitoring system is highly sensitive to corrosion damage. Conversely, when damage is far from the sensing path, the baseline signal and damage signal are almost identical, indicating that this path is insensitive to damage.

To analyze the influence of different degrees of corrosion damage on the uncorrelation coefficient Δ, the damage states of the test specimen were divided into three conditions: (a) No damage; (b) Mild corrosion; (c) Severe corrosion. The uncorrelation coefficient A for all sensing paths when transducer m2C was used as the driving element was extracted, with values for different paths represented by different markers. The closer the corrosion damage is to the sensing path, the larger the uncorrelation coefficient value; the farther the corrosion damage is from the sensing path, the smaller the uncorrelation coefficient value. This validates the feasibility of using standard deviation to define the uncorrelation coefficient as proposed in this paper. Additionally, it can be observed from the figure that as the corrosion degree progresses from no damage to mild corrosion and then to severe corrosion, the uncorrelation coefficient values for the corresponding paths gradually increase.

Figure: ATA-4052C High-Voltage Power Amplifier Specifications and Parameters