Acoustic Emission testing

Acoustic emission testing of zip bridge

Update time：2006-04-18 09:21　　　 Viewed：次

Abroad, acoustic emission health monitoring technology has an extensive practice. The feasibility of the cablestayed bridge and suspension bridge wire fracture monitoring of acoustic emission has been confirmed in practice, and has been gradually used in the field. Acoustic emission can be used to fix the broken wires. The maximum position error is less than 50% % sensor distance, minimum positioning error can be less than + / - 0.5 meters. Acoustic emission has been maturely applied in corrosion detection and monitoring of some structure, such as pressure vessel, oil and gas pipeline and the reinforced concrete structure and so on, but has yet directly use acoustic emission to wire corrosion monitoring. According to experience, it is a little difficult to conduct online corrosion monitoring wire rope by acoustic emission, which is mainly because of the corrosion process of steel cable is said some of the structure of the corrosion process is relatively slow, the corrosion characteristic signals are broken wires signal characteristics, and the environmental noise monitoring for corrosion monitoring device for broken wires of wire will also compare the effect of impact. Of course, the ultrasonic, acoustic emission method of cable corrosion testing may be more effective.

Acoustic emission is used to online monitoring of wire rope broken wires. This online monitoring is similar to other areas of online monitoring, putting multiple acoustic emission sensor wire in axial position. These sensors are connected to an acoustic emission system connected to the Internet or telephone line controlled by a computer. The system controls data acquisition, processing, analysis, alarm and remote computer network communication. Its working principle is: broken wire process will produce strong acoustic emission signal of significant characteristics, which is captured and spread to acoustic emission sensor system, conducting noise removal filter, feature extraction and analysis and the sound source localization and so on, to discriminate positioning and alarm of broken wire. Broken wire positioning is obtained by acoustic emission signal to reach in two adjacent sensors time. Remote monitoring, data analysis and expert's report can also be realized. The key of the reliability of acoustic emission monitoring system lies in the following aspects: proper sensors, acoustic emission system of high speed high quality , noise filtering technology, effective waveform feature extraction and processing technology, effective frequency domain feature extraction and analysis techniques, reliable judgment criteria , effective and continuous monitoring data processing and management software for a long time.
(Editor：admin)

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