基于稀疏导波的裂纹定位和尺寸评估

摘要:

在无损检测中，尤其是导波检测领域，由于缺乏高效方法对材料结构中存在的损伤进行尺寸检测，因此使用导波方法对材料进行微裂缝等损伤的检测的过程中仍然存在很多困难。本文提出一种基于稀疏导波的损伤检测方法，可以在进行结构损伤定位的同时对损伤尺寸进行测量。研究表明，使用导波进行损伤检测时，由损伤而产生的复杂反射波中包括很多与损伤形状和尺寸相关的信息，但是这些信息并不明显，且信号重叠无法区分。因此，提出一种稀疏lamb波方法来分解由材料损伤产生的反射信号的各个分量。在此基础上，通过确定各个反射信号分量相应的传播时间来计算材料损伤尺寸。最后，在具有人工损伤的铝板上进行实验验证，结果表明，基于稀疏导波损伤检测的方法是可行的。

Abstract:

In the use of materials, by various factors, will inevitably produce a lot of damage, damage to the integrity of the material structure, but also has a certain degree of security risks. In the field of non-destructive testing, especially in the field of guided wave testing, there is a lack of efficient methods to detect the size of damage in materials and structures, therefore, there are still many difficulties in the process of using guided wave method to detect micro-cracks and other damages of materials. A damage detection method based on sparse guided waves is stud-ied, which can be used to locate structural damage and measure damage size at the same time. It is shown that the complex reflected wave generated by the damage includes many information related to the shape and size of the damage, but these information are not obvious and the signal overlap can not be distinguished. Therefore, a sparse lamb wave method is proposed to decompose the components of the reflected signal generated by material damage. On this basis, the damage size is calculated by determining the corresponding propagation time of each reflected signal component. Finally, the experimental results on aluminum plate with artificial damage show that the method based on sparse guided wave damage detection is feasible.