IEEE Trans Ultrason Ferroelectr Freq Control. 2016 Sep;63(9):1455-1467. doi: 10.1109/TUFFC.2016.2583410. Epub 2016 Jun 28.
Corrosion damage in inaccessible regions presents a significant challenge to the petrochemical industry, and determining the remaining wall thickness is important to establish the remaining service life. Guided wave tomography is one solution to this and involves transmitting Lamb waves through the area of interest and, subsequently, using the received signals to reconstruct a thickness map of the remaining wall thickness. This avoids the need to access all points on the surface, making the technique well suited to inspection for areas with restricted access. The influence of these areas onto the ability to detect and size surface conditions, such as corrosion damage, using guided wave tomography is assessed. For that, a guided wave tomography system is employed, which is based on low-frequency A0 Lamb waves that are excited and detected with two arrays of electromagnetic acoustic transducers. Two different defect depths are considered with different contrasts relative to the nominal wall thickness, both of which are smoothly varying and well-defined. The influence of areas with restricted surface access, support locations, pipe clamps, and STOPAQ(R) coatings is experimentally tested, and their influence assessed through comparison to a baseline reconstruction without the respective restriction in place, demonstrating only a small influence on the detected value of the remaining wall thickness.
在难以到达的区域的腐蚀损伤对石化行业来说是一个重大的挑战，确定剩余壁厚对于确定剩余使用寿命非常重要。导波层析成像就是解决这个问题的一种方法，它涉及通过感兴趣的区域发送兰姆波，然后使用接收到的信号来重建剩余壁厚的厚度图。这避免了需要访问表面上的所有点，因此该技术非常适合检查那些难以进入的区域。评估了这些区域对使用导波层析成像检测和确定表面状况（如腐蚀损伤）的能力的影响。为此，使用了一种基于低频 A0 兰姆波的导波层析成像系统，该系统使用两个电磁声换能器阵列来激励和检测兰姆波。考虑了两种不同的缺陷深度，它们相对于名义壁厚的对比度不同，并且都是平滑变化且定义明确的。实验测试了具有有限表面可达性的区域、支撑位置、管夹和 STOPAQ(R)涂层的影响，并通过与没有相应限制的基线重建进行比较来评估其影响，结果表明，它们对剩余壁厚的检测值的影响很小。
