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岩石超声检测中最重要的一个环节是初至的拾取,然而该项工作往往费时费力,拾取精度受人为因素影响较大。为提高声波速度检测、声发射定位、以及超声层析成像的应用效率和精度,本研究将地震学中应用比较广泛的AIC初至自动提取技术引入到岩石超声检测中,并进行了适当改进。利用改进前后的AIC方法,自动拾取仿真信号和实际信号的初至,并利用长短时窗比方法(STA/LTA)和手动方法拾取了初至,同时分别与设定的实际初至进行对比。根据实验结果,对于信噪比较低的信号AIC方法要优于STA/LTA方法;改进前的AIC方法适用于起跳干脆、幅度变化大的信号,而改进后的AIC方法则适用于起跳较平缓的信号,且拾取到的初至与手动拾取的初至更加接近。
Rock ultrasonic testing is the most important part of the first pick, but the work is often time-consuming and labor-intensive, the accuracy of the pick-up by human factors. In order to improve the acoustic velocity detection, acoustic emission location and the application efficiency and accuracy of ultrasonic tomography, this study introduced the AIC first-arrival automatic extraction technique, which is widely used in seismology, into the rock ultrasonic testing, and made some improvements. Using the improved AIC method, the first arrival of the simulated signal and the actual signal is automatically picked up, and the first arrival is picked up by using the long / short window ratio method (STA / LTA) and the manual method, and compared with the actual first arrival respectively. According to the experimental results, the signal AIC method with lower signal-to-noise ratio is better than the STA / LTA method; the pre-improvement AIC method is suitable for the signal with simple and large amplitude changes, while the improved AIC method is suitable for taking off relatively flat Signal, and picked up the first arrival and manually picked up the first closer.