Large scale hybrid models for damage detection in arbitrarily shaped concrete structures

TUM2在第一个资助期的工作导致了基于有限元的损害定位方法。对于我们基准的给定维度和使用频率，它被证明工作得非常好。具体地说，实现了以下成果：-开发了使用尾波的基于有限元的损伤定位方法。-开发了一种使用非结构化网格的配方，允许描述任意几何形状-通过嵌入两个高级求解算法改进了已建立的尾部损伤定位问题的解决算法--成功地将基于新的基于有限元的方法应用于真实实验。60 kHz的使用频率代表了利用尾波进行基于灵敏度的损伤定位的新颖性。它将可用频率范围扩展到更适合在大型结构中应用的较低频率范围。在实际实验中的应用表明，由于能够成功地检测和识别多个紧密分布的裂纹，因此本方案的目标是巩固和具体发展我们的方法：(I)捕捉复杂几何形状对尾波测量的影响(Ii)基于测量的尾波数据识别结构模型的参数。这将通过进一步调整本项目第一阶段开发的技术来实现，以满足现实世界的挑战。(3)寻找实地检测损伤的阈值。(4)开发一种数字孪生模型，它使用来自某一结构的所有测量数据来识别和量化特征模型参数。数字双胞胎也将被用来研究结构力学对尾波信号的影响。

The work of TUM2 in the first funding period results in a FE-based damage localization methodology. It was shown to work very well for the given dimensions and used frequencies of our benchmarks. Specifically, the following was achieved:- Development of an FE-based damage localization methodology using coda waves.- Development of a formulation for the use of unstructured meshes that allows description of arbitrary geometries- Improvement of the established solution algorithm for the coda damage localization problem by embedding two advanced solution algorithms- Successful application of the novel FE-based methodology to a real experiment. The used frequency of 60kHz represents a novelty in sensitivity-based damage localization with coda waves. It extends the range of usable frequencies into a lower frequency range that is more suitable for application in large structures. The application in real experiments showed very good results, as several closely spaced cracks could be successfully detected and distinguished.Following this path, the goal of the current proposal is to consolidate and specifically develop our methods to.(i) capture the influences of complicated geometries on the coda measurements(ii) identify the parameters of the structural model based on the measured coda wave data. This will be accomplished by further adapting the techniques developed in Phase 1 of this project to meet real-world challenges. (iii) find thresholds for damage detection in the field.(iv) Develop a digital twin that uses all measured data from a structure to identify and quantify characteristic model parameters. The digital twin will also be used to investigate structural mechanical effects on the coda signal.