基于虚拟源的楔块斜入射全聚焦超声成像  

Total focusing method for ultrasonic imaging for inclined wedge based on virtual source

作　　者：李延伟 于志勇 胡威 胡家元 龙盛蓉[3] LI Yanwei;YU Zhiyong;HU Wei;HU Jiayuan;LONG Shengrong(Hangzhou Yineng Electric Power Technology Co Ltd,Hangzhou 310014,China;Electric Power Science Research Institute of Zhejiang Electric Power Company of State Grid,Hangzhou 310014,China;Key Laboratory of Nondestructive Testing of the Ministry of Education,Nanchang Hangkong University,Nanchang 330063,China)

机构地区：[1]杭州意能电力技术有限公司,浙江杭州310014 [2]国网浙江省电力有限公司电力科学研究院,浙江杭州310014 [3]南昌航空大学无损检测教育部重点实验室,江西南昌330063

出　　处：《传感器与微系统》2023年第6期34-38,共5页Transducer and Microsystem Technologies

基　　金：江西省教育厅项目(GJJ180525);江西省自然基金资助项目(20171BAB206039);杭州意能电力技术有限公司科技项目(EPRD2020—10)。

摘　　要：在楔块斜入射检测工况下,为获得更好的缺陷成像质量,提出一种全聚焦(TF)和虚拟源(VS)相结合的超声成像方法。首先,利用楔块和被检工件界面之间的回波飞行时间在界面上构建VS;然后,借助所建VS,计算双层介质下各阵元的延时时间;最后,对成像区域中的各点进行延时叠加处理,得到斜入射检测工况下的TF图像。结果表明:构建VS引起的信号相位偏差不超过π/2,因而VS-TF图像能够准确呈现出楔块倾角和缺陷的位置。In order to obtain better defect imaging quality under detection condition of wedge oblique incidence,a new ultrasound imaging method,combining total focusing(TF)method and virtual source(VS)technique,is presented.Firstly,the echo time-of-flight between wedge and the checked workpiece is used to build VS at the interface.Then,in virtue of the VS,the delay time of all array elements are calculated in double-medium.Finally,each point in the imaging region is processed by delay stacking,TF image using inclined wedge is obtained.The result shows that phase deviation of signals caused by creating VS is less thanπ/2.Therefore,the wedge angle and the defect location are displayed accurately in the VSTF image.

关 键 词：虚拟源 全聚焦 楔块斜入射 超声成像 

分 类 号：TP212[自动化与计算机技术—检测技术与自动化装置] TG115.28[自动化与计算机技术—控制科学与工程] TH878[金属学及工艺—物理冶金]