摘要
在管道超声导波检测技术的基础上,对不同程度纵向缺陷的损伤检测进行了数值模拟。利用缺陷反射信号对损伤的定位,通过改变管壁局部刚度,研究了缺陷反射信号强度变化的相关规律以及超声导波对缺陷的敏感度,分析了噪声信号对损伤识别的影响,并利用小波的分解和重构算法将信噪分离。结果表明不同程度的信噪比会对超声导波检测法造成一定的影响,通过低通滤噪的方法对信号进行信噪分离,可实现高噪条件下的损伤检测。
A defect identification in pipes by ultrasonic longitudinal guided-wave is proposed. The numerical damage detection signals of the pipe are derived by LS-DYNA, involving the reduced stiffness of elements on the defect location. Furthermore, Wavelet transform is adopted to identify the imperceptibility defect. By means of reflection signal peak intensity, the sensitivity of the proposed approach versus the change of local stiffness in pipe wall is evaluated. The effect of noise on the identified results is also discussed. Defect identification in the low signal-noise ratio is realized based on the algorithm of wavelet decomposition and reconstruction.
出处
《应用力学学报》
CAS
CSCD
北大核心
2009年第4期781-787,共7页
Chinese Journal of Applied Mechanics
基金
国家自然科学基金项目(10672067)
关键词
管道
损伤检测
小波变换
噪声
小波分解和重构
pipe, damage detection, wavelet transform, noise, wavelet decomposition and reconstruction
