Archives of Civil and Mechanical Engineering ( IF 4.4 ) Pub Date : 2022-11-19 , DOI: 10.1007/s43452-022-00564-9 Beata Zima, Jochen Moll
Guided waves have attracted significant attention for non-destructive testing (NDT) and structural health monitoring (SHM) due to their ability to travel relatively long distances without significant energy loss combined with their sensitivity to even small defects. Therefore, they are commonly used in damage detection and localization applications. The main idea of incorporating guided waves in NDT and SHM is based on processing the received signals and appropriate interpretation of their characteristics. A great amount of research devoted to diagnostics of plate-like structures considers specimens with constant thickness, which significantly facilities the diagnostic process. In such a case the velocity is also assumed to be constant. However, the developed diagnostic methods should be applicable, especially for the structures exposed to an aggressive environment, excessive load, or unfavorable weather conditions, etc., when the probability of damage occurring is much higher. In such cases, the assumption about the uniform thickness alongside the propagation path cannot be applied in every case. Thus, the present study is focused on wave propagation in metallic plates with variable thickness. The results of theoretical, numerical and experimental investigations of antisymmetric Lamb mode propagation in aluminum plates with a sine-shaped surface are presented. In the first step, the influence of non-uniform thickness distribution on wave velocity has been described. Next, the inverse problem aimed at shape reconstruction based on time of flight (ToF) analysis and spatially varying wave velocity was solved and compared with the standard dispersion curve-fitting method.
中文翻译:
导波在正弦厚度变化的板状结构中传播的理论和实验分析
导波在无损检测 (NDT) 和结构健康监测 (SHM) 领域引起了极大的关注,因为它们能够传播相对较长的距离而不会造成明显的能量损失,而且它们对小缺陷也很敏感。因此,它们通常用于损伤检测和定位应用。将导波纳入 NDT 和 SHM 的主要思想是基于处理接收到的信号和对其特性的适当解释。大量致力于板状结构诊断的研究考虑了具有恒定厚度的样本,这极大地促进了诊断过程。在这种情况下,速度也被假定为恒定的。但是,开发的诊断方法应该是适用的,特别是对于暴露在恶劣环境、过载或不利天气条件下等的结构,发生损坏的可能性要高得多。在这种情况下,关于沿传播路径厚度均匀的假设不能适用于所有情况。因此,本研究的重点是波在厚度可变的金属板中的传播。给出了正弦形表面铝板中反对称兰姆模式传播的理论、数值和实验研究结果。第一步,描述了非均匀厚度分布对波速的影响。下一个,