Application Cases

【Overview】
In this study, the Aigtek ATA-2021B high-voltage amplifier was used to build a stress-wave-based concrete research system. Monitoring the crack surface effect is crucial for evaluating the damage of reinforced concrete structures under dynamic loads. However, traditional methods (such as X-ray and acoustic emission) have limitations, including surface-only monitoring, high cost, or susceptibility to interference. Although piezoelectric smart aggregate (SA) technology shows promise, its application is constrained by the unclear influence of crack surface effects on stress wave propagation and monitoring signals under different axial compression ratios. Furthermore, existing studies mainly focus on unidirectional and static loading conditions. Therefore, this paper employs low-cycle reciprocating loading tests combined with wavelet packet energy analysis to reveal the influence of crack surface effects on stress wave attenuation.

Experiment Name: Monitoring Study on Crack Surface Effect of RC Compression-Bending Column Based on Piezoelectric Smart Aggregates

Experiment Principle:
This study is based on the theory of stress wave propagation in concrete media and the mechanical-electrical coupling effect of piezoelectric smart aggregates. Low-cycle reciprocating loading tests are conducted to simulate seismic actions. The positive and inverse piezoelectric effects of piezoelectric ceramics are utilized to excite and receive stress wave signals. Wavelet packet energy analysis is employed to process the monitoring signals and quantify the energy attenuation at different damage stages. By systematically varying the key parameter of axial compression ratio and combining experiments with signal analysis, the influence of crack surface effects on stress wave propagation paths and energy attenuation is revealed. The experimental results demonstrate that this method can effectively characterize structural damage evolution, providing a new experimental basis for stress-wave-based internal damage monitoring and quantitative assessment of structures.

Experimental Block Diagram:

Experimental Setup Photos:

Experimental Procedure:
Piezoelectric smart aggregates (SAs) were embedded in the plastic hinge region of the RC compression-bending column. Vertical loads with different axial compression ratios (0.1–0.3) and horizontal low-cycle reciprocating displacement loads were applied. During loading, the upper SA transmitted swept-frequency stress waves (100–50 kHz), while the lower SA received the signals, with simultaneous data acquisition. Wavelet packet energy analysis of the signals showed that the monitoring signal energy decreased with damage development, and the attenuation rate was positively correlated with the axial compression ratio. The energy of the corner SAs decreased rapidly and then stabilized when the inter-story drift ratio was less than 1.14%, while the energy of the middle SAs dropped sharply within the drift ratio range of 0.57%–1.14%. This method effectively validated the feasibility of using SA for monitoring the crack surface effect, with the energy attenuation characteristics corresponding well to the macroscopic stages of crack development.

Application Fields:
Seismic damage assessment of building structures, long-term health monitoring of infrastructure, crack evolution monitoring in buildings, safety operation and maintenance, etc.

Application Scenarios:
Piezoelectric smart aggregates; structural health monitoring; reinforced concrete; wavelet packet energy; axial compression ratio; crack surface effect;

Advantages of Aigtek Amplifiers in This Application:

1. Wide bandwidth coverage and flat frequency response – Precisely outputs swept-frequency signals, ensuring consistency in broadband stress wave excitation.

2. High voltage output and low distortion – Generates highly penetrating stress waves, ensuring measurable received signal energy.

3. High output stability and long-term reliability – Supports continuous monitoring throughout the low-cycle reciprocating loading process, ensuring data comparability.

Recommended Products: ATA-2000 Series High-Voltage Amplifier, ATA-7000 Series High-Voltage Amplifier

Figure: Specifications of the ATA-2000 Series High-Voltage Amplifier

Figure: Specifications of the ATA-7000 Series High-Voltage Amplifier

The experimental materials in this article are compiled and released by Xi'an Aigtek Electronics.