Application Cases

Experiment Name: Application of High-Voltage Amplifier in Damage Identification of Bi-Block Sleeper and Ballast Bed Interface Based on Piezoelectric Ceramics

Experiment Objective:
A placement scheme for simulated thickness-type piezoelectric ceramic patches was proposed for bi-block sleepers, and damage identification research was conducted.

Experimental Equipment:
Piezoelectric actuator, data acquisition card, signal generator, ATA-2022H high-voltage amplifier, test specimens.

Experimental Content:
Five types of sleeper-ballast bed composite specimens were designed and fabricated to represent typical interface conditions between the sleeper and ballast bed: healthy condition, local cracks, partial debonding, complete debonding, and no contact. A method for identifying interface damage between the sleeper and ballast bed was proposed by arranging piezoelectric ceramic pairs near the interface to measure stress waves.

Experimental Procedure:

1. Placement of piezoelectric ceramic patches and platform construction:
   Based on the interface position and transducer vibration mode, appropriate locations on the specimens were selected for attaching the piezoelectric ceramic patches.

   
   

   Figure: Schematic Diagram of Piezoelectric Ceramic Distribution

2. Experimental setup:
   The signal was amplified by the high-voltage amplifier and applied to the actuator. The data acquisition system was used to collect the stress wave responses received by the sensors. The monitoring terminal was used to store and analyze the data.

   

   Figure: Assembly Schematic Diagram

   

   Figure: Experimental Setup

3. Testing process:
   Parameters such as input voltage amplitude and frequency of the excitation signal were selected, and tests were conducted on specimens under five different interface conditions. Using the transmitting-receiving pairs of piezoelectric ceramic patches along paths A-A1, B-B1, and C-C1, five completely separate tests were carried out on the sleeper-ballast bed composite specimens with five different bonding states.

   

   Figure: Schematic Diagram of Test Paths

Experimental Results:
Both sinusoidal excitation and sweep frequency excitation tests were able to identify the conditions of health, local cracks, partial debonding, complete debonding, and no contact. The results were related to the symmetry of the specimens and the arrangement of the piezoelectric ceramic patches.

Figure: Time-domain Amplitude of Response Signals under Sinusoidal Excitation at Different Frequencies

Figure: Total Energy of Response Signals under Sweep Frequency Excitation for Five Different Conditions on the Path

Figure: Specifications of the ATA-2022B High-Voltage Amplifier