论文部分内容阅读
针对传统声发射定位系统存在的结构复杂、难以组网、定位精度低等问题,设计了一种基于光纤布拉格光栅(FBG)传感器网络和时间反转聚焦成像的声发射定位方法。在对时间反转聚焦定位原理分析的基础上,利用四个FBG传感器构建四点定位系统,并采用窄带激光边缘滤波技术实现信号解调。利用Morlet小波提取信号中特定频率成分,并计算模值和时差。通过建立时间反转聚焦模型实现声发射源定位,并在铝合金板结构上对整套成像定位方法进行验证。实验结果表明,该方法能有效地对400mm×400mm监测区域进行声发射定位成像,定位误差小于20mm,耗时小于2s。为声发射检测和定位提供了一种新的方法。
Aiming at the problems of complex structure, difficult networking and poor positioning accuracy of traditional acoustic emission positioning system, an acoustic emission positioning method based on fiber Bragg grating (FBG) sensor network and time-reversed focusing imaging was designed. Based on the analysis of the principle of time-reversed focusing, a four-point positioning system is constructed by using four FBG sensors, and the signal demodulation is realized by the narrow-band laser edge filtering. The Morlet wavelet is used to extract the specific frequency components in the signal, and the modulus and the time difference are calculated. The acoustic emission source localization was achieved by establishing a time-reversed focusing model and the entire imaging positioning method was verified on the aluminum alloy plate structure. Experimental results show that this method can effectively locate and position the 400 mm × 400 mm monitoring area with acoustic emission less than 20 mm and consume less than 2 s. It provides a new method for acoustic emission detection and localization.