Sun Hu, Shao Weihan, Song Jiannan, Yang Xiaofeng, Wang Yishou, Qing Xinlin
School of Aerospace Engineering, Xiamen University, Xiamen 361005, China.
School of Aerospace Engineering, Xiamen University, Xiamen 361005, China.
Ultrasonics. 2023 Apr;130:106935. doi: 10.1016/j.ultras.2023.106935. Epub 2023 Jan 21.
Corrosion is one of the most common damage types which seriously affects structural safety. In this paper, a Lamb wavefield-based monogenic signal processing algorithm is proposed to quantify the corrosion parameters, including location, area, shape and depth, in plate-type structures. The monogenic signal processing based on Riesz transform will cause a serious problem, that is, phase wrapping. To solve this problem, a robust fast phase unwrapping algorithm is developed. Then, the phase spatial distribution of the extracted Lamb wavefield can be extracted, which can be used to calculate the wavenumber distribution. The wavenumber distribution is related to the structure thickness or corrosion depth, which can be further used for corrosion imaging. Simulated Lamb wavefield signals calculated by finite element simulation are employed to evaluate the parameters of circular corrosion and complex umbrella corrosion. The results show that the proposed algorithm has a great advantage in corrosion identification accuracy and calculation time compared with the existing algorithms. A completely non-contact laser ultrasonic system is established for acquiring Lamb wavefield containing square corrosion, and it is proved that the proposed algorithm is able to quantify the corrosion location, area, shape and depth with good accuracy in the experiment.
腐蚀是严重影响结构安全的最常见损伤类型之一。本文提出一种基于兰姆波场的单演信号处理算法，用于量化板型结构中的腐蚀参数，包括位置、面积、形状和深度。基于里兹变换的单演信号处理会导致一个严重问题，即相位缠绕。为解决此问题，开发了一种鲁棒的快速相位解缠算法。然后，可以提取所提取兰姆波场的相位空间分布，用于计算波数分布。波数分布与结构厚度或腐蚀深度相关，可进一步用于腐蚀成像。利用有限元模拟计算得到的模拟兰姆波场信号评估圆形腐蚀和复杂伞形腐蚀的参数。结果表明，与现有算法相比，该算法在腐蚀识别精度和计算时间方面具有很大优势。建立了一套完全非接触式激光超声系统来采集含方形腐蚀的兰姆波场，实验证明该算法能够高精度地量化腐蚀位置、面积、形状和深度。
