Wojtczak Erwin, Rucka Magdalena, Knak Magdalena
Department of Mechanics of Materials and Structures, Faculty of Civil and Environmental Engineering, Gdansk University of Technology, Narutowicza 11/12, 80-233 Gdansk, Poland.
Materials (Basel). 2020 May 8;13(9):2167. doi: 10.3390/ma13092167.
Strengthening of engineering structures is an important issue, especially for elements subjected to variable loads. In the case of concrete beams or slabs, one of the most popular approaches assumes mounting an external reinforcement in the form of steel or composite elements by structural adhesives. A significant disadvantage of adhesive joints is the lack of access to the adhesive film for visual condition assessment, thus, there is a need for non-destructive diagnostics of these kinds of connections. The aim of this paper was the identification and visualization of defects in adhesive joints between concrete beams and steel plates using the guided wave propagation technique. The initial theoretical and numerical analyses were performed. The experimental wave field was excited and measured by the scanning laser Doppler vibrometry. The collected signals were processed by the weighted root mean square (WRMS) calculation. As a result, 2-D damage maps were obtained. The numerical simulations were performed to corroborate the experimental results. The results showed that the guided waves could be successfully applied in non-destructive diagnostics of adhesive joints between concrete and steel elements. However, the quality of damage visualizations strongly depended on the location of excitation.
工程结构的加固是一个重要问题，特别是对于承受可变荷载的构件。对于混凝土梁或板，最常用的方法之一是通过结构胶粘剂以钢或复合材料元件的形式安装外部加固件。胶接接头的一个显著缺点是无法直接观察胶粘剂层的状态，因此，需要对这类连接进行无损检测。本文的目的是利用导波传播技术识别和可视化混凝土梁与钢板之间胶接接头的缺陷。进行了初步的理论和数值分析。通过扫描激光多普勒振动测量法激发和测量实验波场。采集到的信号通过加权均方根（WRMS）计算进行处理。结果得到了二维损伤图。进行了数值模拟以验证实验结果。结果表明，导波可以成功应用于混凝土与钢构件之间胶接接头的无损检测。然而，损伤可视化的质量在很大程度上取决于激励位置。
