光纤声发射源定位实验平台的研究与实现
梁艺军，刘俊锋，张巧萍，吴雷，樊晨光
(哈尔滨工程大学理学院，黑龙江哈尔滨150001)
摘 要：为了研究固体中声发射源定位问题，开发了一套成本低廉，适用范围广，检测灵敏度高的声发射源定位实验系统．采用Sagnac光纤干涉仪作为点传感器构成传感阵列，给出了Sagnac光纤干涉仪超声检测及声源定位的原理；光纤传感器布置在矩形钢板上构成阵列，用模拟声源激励钢板上的任意位置，基于单片机的数据采集电路将四路声发射信号发送给计算机，计算机通过VB编写的软件平台对四路信号进行解调处理．根据四路信号的时间差得到声源的位置，并采用时差修正法提高了定位精度．结果表明，此系统利用光纤传感器实现了钢板中声发射源的定位，为材料结构健康检测与监控的研究提供了一种新的方法．
关键词：声源定位；声发射传感器；无损检测；声发射
中图分类号：TP212；TB523 文献标识码：A文章编号：1006-7043(2010)01-0262-06
An experiment optical fiber platform for the location of acoustic emission sources
LIANG Yi-jun，LIU Jun-feng，ZHANG Qiao-ping，WU Lei，FAN Chen-guang
(College of Science，Harbin Engineering University，Harbin 150001，China)
Abstract：A system for locating sources of the acoustic emissions(AE)caused by strain to a structure was developed．It used an array of optical fiber sensors to identify the location of AE sources in solids．The system possesses the advantages of low-cost，a wide range of applications，and high sensitivity．The sensor array was structured of Sagnac interferometers，each using a point sensor．Principles of the optical fiber ring Sagnac interfemmeter used to detect ultrasonic waves and locate the source were reviewed．These optical fiber sensors were placed on segments of a steel plate to structure the sensor array．Simulated acoustic emissions were generated at various positions on the
steel plate．The data acquisition circuit Was based on single chip．It collected signals from four sensors and sent them to a computer．The computer processed the four signals using an algorithm written in Visual Basic language．
It calculated the position of each source from time differences between the four signals，and the time difference correction method was used to increase the accuracy of location．The results showed that this system and its optical fiber sensors allowed accurate location of all acoustic emission source．It provides a new method for detection and monitoring of structural health．
Keywords：location of sound source；optical fiber sensor；nondestructive testing；acoustic emission
