钢-环氧-钢三明治结构胶层缺陷的导波检测方法研究  

A Guided-Wave-Based Method for Detecting Defects in the Adhesive Layer of the Steel-Epoxy-Steel Sandwich Structure

作　　者：王喜顺 郭昊[1] 朱清锋 杜月浩 苗鸿臣 WANG Xishun;GUO Hao;ZHU Qingfeng;DU Yuehao;MIAO Hongchen(School of Mechanics and Aerospace Engineering,Southwest Jiaotong University,Chengdu 610031,P.R.China)

机构地区：[1]西南交通大学力学与航空航天学院,成都610031

出　　处：《应用数学和力学》2024年第11期1416-1427,共12页Applied Mathematics and Mechanics

基　　金：国家自然科学基金(12172310);中国科协青年人才托举工程项目(YESS20210342);中央高校基本科研业务费(2682024CG014);四川省自然科学基金杰出青年科学基金(25NSFJQ0182)。

摘　　要：钢质环氧套筒广泛应用于油气管道的修复.套筒与管道之间环氧胶层的完整性直接决定了修复质量.由于套筒、环氧胶层和管道一起构成了特殊的三明治结构,传统的无损检测方法难以实现胶层缺陷的有效识别,迫切需要发展新的无损检测方法.该文对钢-环氧-钢三明治结构胶层缺陷的导波检测方法展开了研究.首先通过半解析有限元方法,计算了三明治结构中导波的频散曲线,通过频散特征、波形结构和衰减特性筛选出了可用于胶层缺陷检测的LS_(1)波.接着设计了可用于激励LS_(1)波的压电换能器,并通过数值模拟和实验验证了换能器的有效性.然后,通过数值模拟和实验研究了LS_(1)波与胶层空腔缺陷的作用规律,发现缺陷长度尺寸在4倍波长以内时,LS_(1)波反射波的幅值随缺陷长度变化近似线性变化.在此基础上提出了一种信号处理的方法,当缺陷尺寸不小于2倍波长时,该方法可以有效辨识出缺陷反射信号.Steel epoxy sleeves are widely used to repair oil and gas pipelines.The integrity of the epoxy layer between the sleeve and the pipeline directly determines the quality of the repair.Due to the unique sandwich structure formed by the sleeve,the epoxy layer,and the pipeline,traditional nondestructive testing methods have difficulty effectively identifying defects in the epoxy layer.Therefore,there is an urgent need to develop new nondestructive testing methods.A guided-wave-based method was developed for detecting defects in the adhesive layer of the steel-epoxy-steel sandwich structure.Firstly,the dispersion curves of guided waves in the sandwich structure were calculated with the semi-analytical finite element method.The LS_(1)wave was selected to detect defects in the adhesive layer based on the dispersion characteristics,waveform structures,and attenuation properties.Subsequently,a piezoelectric transducer capable of exciting LS_(1)waves was designed.The effectiveness of the transducer was verified through numerical simulations and experiments.Then,numerical simulations and experiments were conducted to study the interaction between LS_(1)waves and cavity defects in the adhesive layer.The results show that,with a defect length within 4 times of the wavelength,the amplitude of the LS_(1)wave's reflected wave would change approximately linearly with the defect length.Based on this,a signal processing method is proposed,which can effectively identify defect reflection signals when the defect size is not less than twice the wavelength.

关 键 词：三明治结构 超声导波 压电换能器 黏接层 无损检测 

分 类 号：O343.3[理学—固体力学]