基于超声反射法的环氧树脂复合材料内部缺陷检测与频谱分析研究  

Research on internal defect detection and spectrum characteristics of epoxy resin composites based on ultrasonic reflection method

作　　者：吕立翔[1] 杨卓然 刘剑 朱炫培 LÜLixiang;YANG Zhuoran;LIU Jian;ZHU Xuanpei(State Grid Nanjing Power Supply Company,Nanjing 210000,China)

机构地区：[1]国网南京供电公司,江苏南京210000

出　　处：《绝缘材料》2024年第9期131-139,共9页Insulating Materials

基　　金：国家电网公司总部科技项目(5200-202311159A-1-1-ZN)。

摘　　要：纤维增强树脂基复合材料被广泛地应用在电力设备中,其涉及多层介质,结构复杂,内部易产生缺陷,在长期电场作用下会引发局部放电甚至绝缘击穿。对绝缘内部缺陷进行早期检测,可以有效减少事故的发生。本文基于超声反射法搭建了复合材料超声检测系统,基于真空树脂传递模塑法人工制备了含裂纹、分层和金属杂质缺陷的玻璃纤维增强环氧树脂复合材料平板试样,然后分别对含缺陷的平板试样进行超声检测与频谱分析。结果表明:不同种类缺陷试样的超声反射波形存在明显差异。通过对超声回波进行频谱变换,得出归一化频谱特性曲线,根据曲线计算特征值可以实现对不同形态缺陷的识别。其中裂纹缺陷试样的特征值最小,分层缺陷试样的特征值最大。Fiber reinforced epoxy resin composites are widely used in electrical power equipment.However,due to their complex preparation process and multi-layered structure,internal defects are prone to be introduced during manufacture,which may lead to partial discharge and even breakdown under long-term high voltage operating condition.Early detection of these defects can significantly reduce the occurrence of failures.In this paper,an ultrasonic testing system for composite was established on the basis of ultrasonic reflection method,and various plate samples of glass fiber reinforced epoxy resin composites containing artificial crack,delamination,and metal impurity defect were prepared on the basis of vacuum assisted resin infusion molding method.Ultrasonic testing and spectral analysis were then conducted on these defectcontaining plate samples.The results indicate that there are significant differences in the ultrasonic reflection waveforms for different defects of samples.By transforming the ultrasonic echoes into frequency spectra,the normalized spectral characteristic curves are obtained,and different types of defects can be identified by calculating the characteristic values from these curves.The characteristic value of the sample with crack defect is the smallest,and the characteristic value of the sample with delamination defect is the largest.

关 键 词：环氧树脂复合材料 超声反射法 回波分析 频谱变换 缺陷识别 

分 类 号：TM215[一般工业技术—材料科学与工程]