Local damage monitoring system and method based on extrinsic optical-fiber acoustic emission

Abstract

The invention discloses a local damage monitoring system and local damage monitoring method based on extrinsic optical-fiber acoustic emission. The system comprises an acoustic emission sensor apparatus; an optical-fiber transmission apparatus; and a data processing apparatus. The acoustic emission sensor apparatus is used for monitoring acoustic emission signals of a monitored object and for converting the acoustic signals into electric signals. A sending terminal of the optical-fiber transmission apparatus is connected with the acoustic emission sensor apparatus. Electric signals transmitted from the acoustic emission sensor apparatus are subjected to signal conditioning and analog-to-digital conversion, such that the signals are converted into digital signals. The digital signals are modulated into optical signals, and are transmitted to a receiving terminal through optical fiber transmission. With an optoelectronic demodulation module, the receiving terminal restores the optical signals into electric signals. The data processing apparatus carries out data analysis upon the electric signals containing the acoustic emission signals collected on-site by the acoustic emission sensor apparatus; and damage information is picked up, and a processing result is finally generated. The system and the method provided by the invention are rarely affected by work site complexity and harsh environments, and have high interference resistance. The system and the method are advantaged in accurate monitoring. With the system and the method, distant structure-activity defect monitoring can be implemented, and network monitoring can easily be formed. The system and the method are suitable for distant monitoring, and a monitoring procedure is safe.

Description

technical field [0001] The present invention relates to the field of structural fatigue damage and fracture technology, more precisely to the field of non-destructive testing technology for online monitoring of cracks and other active defects. The system can be widely used in the health monitoring and monitoring of mechanical (especially lifting machinery) structures. Diagnostic evaluation. Background technique [0002] Hoisting machinery is the "backbone" of major industrial industries and is widely used in various fields such as metallurgy, chemical industry, electric power, port, construction, and manufacturing. In order to improve operating efficiency, cranes have been developed towards large-scale, high-speed, high-efficiency and low failure rates. The hoisting machinery is subjected to adverse factors such as load, fatigue and material aging during the long service process, and it has been continuously working in a relatively harsh environment for a long time, which g...

AI Technical Summary

Problems solved by technology

Acoustic emission monitoring technology is a better technical means for monitoring structural active defects (such as cracks, etc.), but due to the complex working site of lifting machinery and the harsh environment, the traditional signal transmission method has the disadvantages of limited transmission distance and susceptibility to interference. , which brings difficulties to the traditional acoustic emission monitoring

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