改良线性调频脉冲压缩在空耦超声混凝土检测中的应用  

Application of improved linear-frequency-modulation based pulse compression in air-coupled ultrasonic concrete testing

作　　者：常俊杰[1,2] 曾雪峰 CHANG Junjie;ZENG Xuefeng(Key Laboratory of Nondestructive Testing,Ministry of Education,Nanchang Hangkong University,Nanchang 330063,China;Japan Probe Co.,Ltd.,Yokohama 2320033,Japan)

机构地区：[1]南昌航空大学无损检测技术教育部重点实验室,江西南昌330063 [2]日本探头株式会社,日本横滨2320033

出　　处：《混凝土》2019年第12期161-164,172,共5页Concrete

基　　金：国家自然科学基金资助项目(11464030);无损检测技术教育部重点实验室(南昌航空大学)开放基金课题项目(F010404)

摘　　要：针对空气耦合超声检测混凝土时检测信号强度低、信噪比低、以及使用普通线性调频脉冲压缩方法可能会产生波形畸变等问题,提出一种改良的线性调频脉冲压缩信号处理方法。阐述了改良线性调频脉冲压缩原理。制备有通孔树脂块试件,使用空气耦合V透射法对试块通孔检测,对比普通脉冲压缩和改良脉冲压缩方法对信号处理结果,验证该方法正确性、稳定性;制作混凝土试样,对比普通脉冲压缩和改良脉冲压缩方法信号处理结果。结果表明:相较于传统超声和普通脉冲压缩方法,使用改良的线性调频脉冲压缩方法后超声信号的灵敏度、信噪比、空间分辨率得到改善。A improved linear-frequency-modulation pulse compression signal processing method is proposed for detecting the low signal strength,low signal-to-noise ratio,and the distortion of waveform caused by the traditional linear-frequency-modulation pulse compression method in the detection of concrete with air-coupled ultrasound.Explain the principle of improved linear-frequency-modulation pulse compression.The through-hole resin block test piece was prepared,and the air-coupling V-transmission method was used to detect the through-hole of the test block.The signal processing results were compared with the ordinary linear-frequency-modulation pulse compression and the improved linear-frequency-modulation pulse compression method to verify the correctness and stability of the method.Making concrete specimens,comparing the results of normal linear-frequency-modulation pulse compression and improved linear-frequency-modulation pulse compression method.The results show that the signal sensitivity,signal-to-noise ratio and spatial resolution of concrete are improved by using improved linear-frequency-modulation pulse compression method compared with ordinary pulse compression method.

关 键 词：空气耦合超声 线性调频 脉冲压缩 混凝土 

分 类 号：TU528.07[建筑科学—建筑技术科学]