Grabke Stefan, Clauß Felix, Bletzinger Kai-Uwe, Ahrens Mark Alexander, Mark Peter, Wüchner Roland
Chair of Structural Analysis, TU München, Arcisstraße 21, 80333 München, Germany.
Chair of Concrete Structures, Ruhr-Universität Bochum, Universitaätstraße 150, 44801 Bochum, Germany.
Materials (Basel). 2021 Sep 2;14(17):5013. doi: 10.3390/ma14175013.
Reinforced concrete is a widely used construction material in the building industry. With the increasing age of structures and higher loads there is an immense demand for structural health monitoring of built infrastructure. Coda wave interferometry is a possible candidate for damage detection in concrete whose applicability is demonstrated in this study. The technology is based on a correlation evaluation of two ultrasonic signals. In this study, two ways of processing the correlation data for damage detection are compared. The coda wave measurement data are obtained from a four-point bending test at a reinforced concrete specimen that is also instrumented with fibre optic strain measurements. The used ultrasonic signals have a central frequency of 60 kHz which is a significant difference to previous studies. The experiment shows that the coda wave interferometry has a high sensitivity for developing cracks and by solving an inverse problem even multiple cracks can be distinguished. A further specialty of this study is the use of finite elements for solving a diffusion problem which is needed to state the previously mentioned inverse problem for damage localization.
钢筋混凝土是建筑行业中广泛使用的建筑材料。随着结构使用年限的增加和荷载的增大，对既有基础设施的结构健康监测有着巨大的需求。尾波干涉测量法是一种用于混凝土损伤检测的可行方法，本研究证明了其适用性。该技术基于对两个超声信号的相关性评估。在本研究中，比较了两种处理相关性数据以进行损伤检测的方法。尾波测量数据来自对一个钢筋混凝土试件进行的四点弯曲试验，该试件还配备了光纤应变测量装置。所使用的超声信号中心频率为60kHz，这与之前的研究有显著差异。实验表明，尾波干涉测量法对裂纹扩展具有高灵敏度，并且通过求解反问题甚至可以区分多个裂纹。本研究的另一个特点是使用有限元来解决扩散问题，而这是陈述前面提到的用于损伤定位的反问题所必需的。
