Coda wave based ultrasonic methods for concrete - extending the capabilities by using 3d information combination with acoustic emission and exploitation of additional features towards the application on real structures

该子项目在课务组内负责超声尾数据测量的实际部分（包括支持其他实验项目），两种成像方法之一用于定位物体变化，以及该方法未来在实际结构上的实际应用方面。为此，通过研究换能器和多功能低成本数据采集系统，在第一阶段成功地奠定了仪器基础。开发并成功测试了一种创新的尾波成像方法来定位损伤，但目前仅限于二维（即一个平面）。此外，根据在野外对大型标本的测量，已经开发了一种消除环境影响（例如，温度）的方法，使任何损坏事件更加明显。此外，第一个真正的结构已经提前进行了仪器测量，并不断收集数据。在第二阶段，现在将进行系统的研究，以扩展和拓宽基本原理，以便该方法可以在未来用于实际结构。在这里，我们不仅将为更大的传感器网络提供更快的数据采集，而且还将为测试目的提供至少一个真实结构的仪器。我们还将开发传感器，分别记录波场的三个空间分量。我们将在成像过程中使用这些信息，这些信息已经扩展到三维，以获得更好的物体变化图像。我们将把这一结果与声发射分析的结果结合起来，进一步提高结果的准确性。此外，通过新的传感器，以及与合作伙伴进行的模拟和实验，我们将能够从数据中提取额外的参数。这些包括非线性材料行为的参数，但也使用环境影响（而不仅仅是消除）作为对物体的任何损坏的指标。我们将与我们的合作伙伴一起在仪器化的真实结构上验证我们的结果。

This subproject is responsible within the research group for the practical part of the ultrasonic coda measurements (including support of the other experimental projects), one of the two imaging methods for the localization of changes in the objects as well as aspects of the future practical application of the methodology on real structures. To this end, the instrumental foundations were successfully laid in phase 1 by working on the transducers and a versatile, low-cost data acquisition system. An innovative method for imaging coda waves to localize damage was developed and successfully tested but is currently limited to 2D (i.e. one plane). In addition, based on measurements on a large specimen in the open field, a methodology for eliminating environmental effects (e.g., temperature) has been developed that makes any damage events more visible. In addition, the first real structure has already been instrumented ahead of schedule and data collected on an ongoing basis.In phase 2, systematic research will now be conducted to extend and broaden the basic principles so that the method can be used on real structures in the future. Here, we will not only provide faster data acquisition for even larger sensor networks and instrument at least one more real structure for testing purposes. We will also develop sensors that separately record the three spatial components of the wave field. We will use this information in the imaging process, which has been expanded to three dimensions, to obtain better images of the changes in the object. We will combine this with results from acoustic emission analysis to further sharpen the results.In addition, with the new sensors, but also through simulations and experiments performed with the partners, we will be able to extract additional parameters from the data. These include parameters on nonlinear material behavior, but also the use of environmental effects (instead of just elimination) as an indicator of any damage to the object. We will verify our results on instrumented real structures together with our partners.