Application Cases

Experimental Name: Crack Monitoring of PCCP Mortar Protective Layer and Pipe Concrete under External Pressure

Experimental Content: Using a high-voltage power amplifier to amplify the voltage amplitude, exciting PZT transducers to generate Rayleigh waves for monitoring cracks in the PCCP mortar protective layer and pipe concrete.

Research Focus: Structural Non-destructive Monitoring and Safety Assessment

Test Equipment: ATA-4011C high-voltage power amplifier, dynamic data acquisition instrument, battery, PZT, etc.

Figure: Experimental Block Diagram of Crack Monitoring for PCCP Mortar Protective Layer and Pipe Concrete

Experimental Process:
A PCCP with an inner diameter of 1.4 meters was subjected to external pressure loading from 0 to 700 kN. During the 0–300 kN phase, the load was increased in 100 kN increments, with a 3-minute stabilization period after each step. After 300 kN, the load increment was reduced to 50 kN per step to facilitate observation of experimental phenomena. The test was loaded up to 700 kN, at which point the pipe was visibly deformed into an elliptical shape, and the mortar protective layer had separated from the pipe concrete. During the loading process, sinusoidal signals at 5 kHz, 10 kHz, and 20 kHz were selected as excitation signals to monitor cracking in the mortar protective layer and pipe concrete. The voltage amplitude was set to 10 V, and the ATA-4000 high-voltage amplifier was used to achieve a 5× voltage gain.

Experimental Results:

Figure: Experimental Results

The damage indices RPDA and RPDE at frequencies of 5 kHz, 10 kHz, and 20 kHz demonstrated sensitivity to cracking in both the mortar protective layer and the pipe concrete under external pressure loading. Overall, RPDA at 20 kHz is the preferred method for monitoring cracking in the mortar protective layer, while RPDA at 20 kHz and RPDE at 10 kHz are suitable choices for monitoring cracking in the pipe concrete.

Power Amplifier Recommendation: ATA-4011C High-Voltage Power Amplifier

Figure: ATA-4011C High-Voltage Power Amplifier Specifications and Parameters