Evaluating soundness of concrete structures by Lamb and Rayleigh waves

研究了Lamb和Rayleigh在建立混凝土结构维护和诊断的有效无损评估方法方面的可行性。(1)确定了混凝土弹性性能变化引起的Lamb波的频散；(2)提出了一种利用瑞雷波振幅变化与裂缝深度的关系来定量评价混凝土裂缝的方法；(3)以瑞雷波的相速度为输入，利用层析重建技术实现了混凝土内部缺陷的可视化。

Research was carried out to examine the feasibility of Lamb and Rayleigh in establishing efficient non-destructive evaluation methods for maintenance and diagnosis of concrete structures. The following are findings based on fundamental experimental studies : (1) Dispersion of Lamb waves due to the change in elastic properties of concrete was confirmed ; (2) A quantitative method for evaluating concrete crack utilizing the relation between Rayleigh wave amplitude change and crack depth can be proposed, (3) With phase velocity of Rayleigh waves as input, defect inside concrete can be visualized using tomography reconstruction technique.