f-k域内混凝土结构损伤的时间逆转成像算法研究  

TIME REVERSAL IMAGING METHOD OF CONCRETE STRUCTURE DAMAGE IN FREQUENCY-WAVENUMBER DOMAIN

作　　者：赵国旗[1] 陈晓君[1] 骆英[1] 徐桂东[2] 徐晨光[2] 

机构地区：[1]江苏大学土木工程与力学学院,江苏镇江212013 [2]江苏大学理学院,江苏镇江212013

出　　处：《建筑技术》2017年第1期92-94,共3页Architecture Technology

基　　金：国家自然科学基金项目(11272138);高等学校博士学科点专项科研基金优先发展领域课题(20123227130002)

摘　　要：将频率波数(f-k)域的快速逆时损伤成像方法应用于混凝土结构损伤检测中。在f-k域内,基于纵波波动方程与格林函数获取了入射波场与逆转散射波场的解析表达式,利用有限元法模拟含损伤的混凝土结构中的超声波场,并得到散射回波,进而采用互相关成像条件评价混凝土结构损伤。该法成像速度比时域内已有时间逆转法提升约2个数量级。将时间逆转互相关成像结果与多重信号分类(MUSIC)法成像结果进行比较。结果表明,相比于多重信号分类法,时间逆转互相关成像法能提供更多损伤的几何信息。The time reversal cross-correlation imaging method is used to detect damages in concrete structures in the frequency-wavenumber （f-k） domain. Based on the wave equation and Green＇s function, both incident wavefield and scattered wavefield are derived. Numerical simulations are conducted to simulate the ultrasonic wavefield in concrete structures including damages. After collecting the scattered wave data, a fast damage imaging method has been developed by using the cross-correlation between the back-propagated scattered wavefield and the incident wavefield in the frequency domain. At the same time, this method has higher imaging efficiency which is about two orders of magnitude faster than the traditional time reversal method in the time domain. Comparing to the MUSIC method, time reversal cross-correlation imaging method has higher efficiency and it can also localize the damage more accurately.

关 键 词：混凝土结构 时间逆转法 频率波数域 互相关成像 

分 类 号：TU317.5[建筑科学—结构工程]