基于小波散射网络的聚乙烯管道热熔接头缺陷太赫兹识别  

Terahertz Identification of Hot Melting Joint Defects in Polyethylene Pipe Based on Wavelet Scattering Network

作　　者：徐继升 任姣姣 张丹丹[1,2,3] 顾健 张霁旸[3] 李丽娟 薛竣文[3] XU Jisheng;REN Jiaojiao;ZHANG Dandan;GU Jian;ZHANG Jiyang;LI Lijuan;XUE Junwen(Key Laboratory of Photoelectric Measurement and Optical Information Transmission Technology of Ministry of Education,Changchun University of Science and Technology,Changchun 130022,China;College of Optoelectronic Engineering,Changchun University of Science and Technology,Changchun 130022,China;Zhongshan Institute of Changchun University of Science and Technology,Zhongshan 528400,China)

机构地区：[1]长春理工大学光电测控与光信息传输技术教育部重点实验室,长春130022 [2]长春理工大学光电工程学院,长春130022 [3]长春理工大学中山研究院,中山528400

出　　处：《光子学报》2023年第1期137-148,共12页Acta Photonica Sinica

基　　金：吉林省科技发展计划(No.20220508032RC)。

摘　　要：采用频率范围为0.25~2.5 THz的反射式脉冲太赫兹时域光谱系统,对聚乙烯管道热熔接头缺陷进行了无损检测。利用PE100板材之间的热熔焊接模拟实际聚乙烯管道的热熔焊接,分别制作了标准热熔焊接和冷焊、过焊、未熔合和夹杂热熔缺陷接头样件。通过太赫兹系统逐点扫描,并对接头位置进行了波形及峰度成像分析。其中未熔合和夹杂热熔缺陷样件与标准焊接样件在波形上有明显差别;冷焊、过焊、未熔合及夹杂热熔缺陷在峰度成像图中可见明显缺陷轮廓。针对标准焊接和夹杂、未熔合热熔缺陷构建第一类小波散射网络-卷积神经网络缺陷识别模型进行缺陷定性分析,其缺陷识别率均可达到98%以上。针对标准焊接和夹杂金属、粗沙、树枝缺陷构建第二类缺陷识别模型进行定量识别,其缺陷识别相对误差均在7.42%以下。Polyethylene pipelines have become the first choice in the field of gas and oil pipelines due to their advantages in corrosion resistance, plasticity and cost performance. Because of their flammable and explosive characteristics, natural gas and oil are prone to safety hazards, so the quality should be strictly controlled in production and use. PE pipes are usually welded on site during laying. Human factors, longterm weathering and corrosion effects in the welding process may lead to defects in the welded joints of pipes. Therefore, the quality inspection of welded joints of pipes is particularly important. At present, the detection methods of hot-melt joints mainly include ultrasonic testing, infrared thermal imaging detection, ray detection, etc. These detection methods have certain limitations in the actual polyethylene pipeline detection.As a non-destructive, non-ionizing, non-contact new detection technology, Terahertz nondestructive testing technology has a strong penetration of non-polar, non-metallic materials. The nondestructive testing technology based on THz imaging technology can obtain the frequency domain, time domain and spatial information of the tested sample, and can clearly image the defects of the material. With high defect detection and positioning ability, it is gradually gaining prominence in the field of nondestructive testing, which can be used as an effective supplement to traditional testing technology.In order to solve the problems of cold welding, over-welding, non-fusion and inclusion defect detection of PE pipe hot-melt joints, reflective pulsed terahertz time-domain spectroscopy with a frequency range of 0.25~2.5 THz is used to detect PE hot-melt joints. The hot-melt welding between PE100 sheets is used to simulate the actual hot-melt welding of polyethylene pipes. Standard hot-melt welding and cold welding, over welding, incomplete fusion and inclusion hot-melt defect joint samples are made. Through point-by-point scanning of terahertz system, the wave pattern and kurtosis imagin

关 键 词：太赫兹 无损检测 聚乙烯热熔接头 小波散射网络 缺陷识别 

分 类 号：O451[理学—无线电物理]