1、 I 摘 要 声发射( Acoustic Emission，AE) 是材料中局域源快速释放能量而产生瞬态弹 性波的一种现象，有时又称作应力波发射。传统的压电声发射传感器体积大，频 带窄，受电磁干扰比较严重，在强电场、高温环境下其有效性受到很大制约。而 光纤 AE 传感器具有体积小、频带宽、灵敏度高、损坏阈值高、不必与被测物体接 触、适用于恶劣环境等优点。因此，光纤声发射检测技术有很重要的研究意义。 基于光纤 Sagnac 干涉效应，建立一套光纤声发射传感系统,并分析其系统构成 和测量原理，建立标准声发射采集系统并进行室内实验。完成对三个声源信号： 断铅信号、摩擦信号和敲击信号的采集测试，以及激
2、励源的脉冲信号分析。实验 结果表明，与传统声发射检测系统相比，新型光纤声发射检测系统具有整体简单， 操作简易，设备体积小，获得测量信号更贴近真实信号等优点。 关键词： 声发射 ；光纤声发射检测；Sagnac 干涉效应 II ABSTRACT Acoustic Emission means the phenomenon that partial fast release energy with the transient elastic wave in different materials, sometimes it is also called stress wave emission. T
3、raditional piezoelectric acoustic emission sensor is large, frequency band is narrow, and have serious electromagnetic interference, in high temperature environment or in a strong electric field, its effectiveness is limited. The optical fiber AE sensor has the advantages of small volume, wide frequ
4、ency band, high sensitivity, high damage threshold, not contact the measured object ,suitable for harsh environment. Therefore, the research on optical fiber acoustic emission detection technology has a very important significance. Based on the interference effect of Sagnac, a set of optical fiber a
5、coustic emission sensor system is established, and the system structure and measuring principle are analyzed. Complete the acquisition and testing of three sound source signals: the signal of lead, the friction and the signal, pulse signal analysis of excitation source The experimental results show
6、that compared with the traditional acoustic emission detection system, the new fiber optic acoustic emission testing system has the advantages of simple operation, simple operation, small equipment etc. Key words: Acoustic emission; fiber optic acoustic emission detection; the effect of fiber Sagnac interferome III 目 录 第第 1章章 绪论绪论. 1 1.1 选题背景及意义. 错误错误!未定义书签。未定义书签。 1.2 传统声发射的发展历程和研究现状. 2 1.3 光纤声发射技术国内外研究现状. 3 1.3.1 光纤声发射技术国外研究现状.3 1.3.2 光纤声发射技术国内研究现状.5 1.4本课题的主要研究内容5 第第 2章光纤声发射检测系统理论基础章光纤声发射检测系
