Application Cases

Bolts are temporary connectors, and bolted connections are the primary method for connecting timber structures, widely used in construction, transportation, and other fields. However, during long-term use, bolted connections may experience issues such as reduced pre-tightening force, misalignment at the connection interface, or even loosening, which can seriously threaten the structural integrity and functionality of the bolted connection system. Therefore, regular monitoring of bolt loosening is necessary. Among various piezoelectric materials, piezoelectric ceramics (PZT) are widely used in vibration control and non-destructive testing of structures due to their low cost, lightweight, simple structure, and strong energy harvesting capability. PZT can be utilized to monitor the load of pin-connected structures.

Aigtek's high-voltage amplifiers are widely used in the field of power electronics. Depending on the parameters of different piezoelectric materials, there are suitable instruments that can drive most piezoelectric ceramics on the market.

Experimental Name: Design of a Bolt Connection Loosening Detection System for Timber Structures

Experimental Principle:
Two piezoelectric ceramics (PZT) are attached to two bolted timber structures. One PZT generates an ultrasonic signal, while the other PZT converts the transmitted ultrasonic signal into an electrical signal. After time reversal, the ultrasonic signal is regenerated, and the transmitted ultrasonic signal is collected again. By connecting a computer, data acquisition card, piezoelectric ceramics, and a high-voltage amplifier, the hardware of the bolt loosening detection system is established. System software with Lamb wave impact signal generation and secondary digital trigger acquisition functions is implemented on the LabVIEW platform. By applying different pre-tightening forces to the timber structure, the relationship between the focused signal amplitude and the bolt axial pre-tightening force is tested.

Experimental Block Diagram:

Laboratory Setup Photo:

Experimental Process:
Set specific signal wave commands in the LabVIEW software, and generate specific monitoring signals through the data acquisition card. The monitoring signal is amplified by the ATA-2021B high-voltage amplifier to excite the PZT, generating ultrasonic signals. The ultrasonic signals propagate within the monitored timber structure and are received by another PZT. The received ultrasonic signals are converted into electrical signals and collected by the data acquisition card. The collected electrical signals are displayed and analyzed in the LabVIEW software to assess the tightness of the bolted connection.

Application Fields:
Architectural Structures, Furniture Manufacturing, Wood Product Processing

Application Scenarios:
Bridge Structure Monitoring, Ancient Building Preservation, Furniture Quality Inspection, Wood Product Transportation Safety

Product Recommendation: ATA-2000 Series High-Voltage Amplifier

Figure: ATA-2000 Series High-Voltage Amplifier Specifications and Parameters

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