非金属管道损伤的非线性超声导波延时检测定位方法

发布时间：2018-07-25 19:26

【摘要】：由于超声导波难以准确检测非金属管道的早期损伤,本文提出了一种非线性超声导波延时方法对非金属管道结构损伤进行测试和定位。基于非线性超声调制机理分析了非金属管道损伤状态,使用同侧非线性超声的混频信号激励方式并根据超声导波传播速度的差异产生激励信号延时,然后在管道损伤处实现混频信号的非线性调制。采用HHT(Hilbert-HuangTransformation)提取混频延时信号的瞬时特征量,并通过分析非线性分量延时分组进行损伤区域检测,实现了对非金属管道裂纹损伤的定位。PVC(Ployninylchloride)非金属管道实验显示,无损伤状态下延时信号分组的标准化基准值为0.518 8;单裂纹状态下延时信号分组标准值为0.593 7,损伤定位相对误差为3.277%;双裂纹损伤状态下的标准化瞬时平均幅值为0.580 1与0.607 3,损伤定位值绝对误差小于4mm。相对于利用小波包络分解的非线性延时定位检测法,实验得到的单裂纹损伤准确度提高了36.4%。结果表明该方法能够对非金属管道裂纹损伤准确定位,并能够检测早期多裂纹损伤。
[Abstract]:Because ultrasonic guided wave is difficult to detect the early damage of non-metallic pipeline accurately, a nonlinear ultrasonic guided wave delay method is proposed to detect and locate the damage of non-metallic pipeline structure. Based on the nonlinear ultrasonic modulation mechanism, the damage state of the non-metallic pipeline is analyzed. The excitation signal delay is generated by using the mixed mode of the ipsilateral nonlinear ultrasonic and the difference of the velocity of the ultrasonic guided wave. Then the nonlinear modulation of the mixing signal is realized at the damage point of the pipeline. HHT (Hilbert-HuangTransformation) is used to extract the instantaneous characteristic of the mixing delay signal, and the damage area is detected by analyzing the nonlinear component delay grouping. The standard reference value of delay signal grouping in non-damage state is 0.518 8, the standard value of delay signal grouping in single crack state is 0.593 7, the relative error of damage location is 3.277 and the standardized instantaneous average amplitude is 0.580 in the case of double crack damage. 1 and 0.607 3, the absolute error of damage location value is less than 4 mm. Compared with the nonlinear time-delay localization method based on wavelet envelope decomposition, the accuracy of single crack damage is improved by 36.4%. The results show that this method can accurately locate the crack damage in non-metallic pipeline and can detect the early multi-crack damage.
【作者单位】：华南理工大学机械与汽车工程学院;
【基金】：国家自然科学基金资助项目(No.51305141) 广东省自然科学基金资助项目(No.2014A030313248) 广州市科技计划项目(No.201607010171)
【分类号】：U178

【相似文献】