摘要
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。
The onset time picking is one of the most important procedures of ultrasound testing of rock, which is always a time-consuming effort. The picking precision is easily influenced by artificial factors. To improve the accuracy and the efficiency of acoustic velocity measurement of rock, the location of acoustic emission and ultrasonic tomography, the technique of AIC for automatic onset time picking, widely used in seismology, is introduced to the ultrasound testing of rock and is improved appropriately. In this paper, the onsets of simulated and actual signals are picked with AIC and improved AIC, respectively; and all the picking results are compared with the actual arrival time （just for simulated signals） and onset time picked by artificial and STA/LTA method. According to the experiment results, the AIC is superior to the STA/LTA method, for signals with low SNR; the AIC works better for signals with sharp onset and fast amplitude variation, and improved AIC is more suitable for signals with gentle onsets to pick the first arrivals; and the picking results of the latter are closer to the artificial results than the former.
出处
《CT理论与应用研究（中英文）》
2015年第2期225-238,共14页
Computerized Tomography Theory and Applications
基金
国家自然科学基金(41104117)
