A special meeting of the CoDA Group took place in Munich from July 22 - 23.

On Monday, July 22, the members of the CoDA group made their appearance in front of the camera. In cooperation with Stadtwerke München (SWM) and a professional production team, scenes were recorded for two short films. Once completed, the short films are intended to inform a broader audience about current structural monitoring, as well as the CoDA Group's research and cooperation with SWM. All current and former members of the research group were invited to the video shoot.

The CoDA research group organized a Special Session Concrete Damage Assessment using CODA Waves at IALCCE2023 (Eighth International Symposium on Life-Cycle Civil Engineering) in Milan. During the Special Sesson on Wednesday, 05 July 2023 the presented contributions covered the entire spectrum of the CoDA research unit.

The presented results were published within the conference proceedings: https://doi.org/10.1201/9781003323020

On May 5^th a joint digital conference of Siemens and TU Munich took place on the topic of “Simulation and Digital Twin”. With the Coda technology having a huge potential on structural health monitoring, the technology and first results on damage detection were presented to a broad audience. PD Dr. Roland Wüchner shared insights in his talks on “Simulation & Digital Twin – The enabler of cutting-edge products and services“.

The influence of temperature changes in a component on the codasignal was investigated at the Ruhr University Bochum on a reinforced concrete beam of 3.5 m length with rectangular cross-section (w = 0.25 m x h = 0.5 m). Different temperature states (constant and linearly varying over the height) were investigated by established as well as novel temperature measurement techniques (thermocouples, infrared camera, fiber optics). Special attention was paid to the comparison of the measured temperature fields with ultrasonic attribute maps.

Ten ultrasonic sensors were successfully installed in the tension member at the Gänstorbrücke in Ulm during the week of 21.09.2020-25.09.2020. By means of regular measurements with attached and embedded sensors, changes in the structural component are to be detected using coda wave interferometry. Thanks to the sensor technology already installed by the engineering office Schiessl Gehlen Sodeikat and the company Vallen Systems, the measurement results can be compared with common methods (acoustic emission, strain gauges) in case of suspicion. The research group hopes that this will provide further insights to improve damage detection and differentiation with coda waves on real components.

Furthermore, 20 sensors could be embedded in the middle of the bridge in the same week. This experiment is part of a project financed by the Federal Road Research Institute (BASt). The research group should also benefit from the evaluation of the data in the middle of the bridge.

Report of the Bayerischer Rundfunk

The status of the subprojects are discussed at the plenary meeting at the Institute of Concrete Structures at the Ruhr University Bochum. The results of the experiments at micro and structural levels as well as the approaches for the corresponding material models are presented and the further procedure for their coordination is examined. In addition, the instrumentation of a building, the Gänstor bridge in Ulm with already installed measuring technology in the form of acoustic emission, strain and temperature measurement, is determined. The meeting is complemented by a visit to the Bochum Jahrhunderthalle.

The first doctoral workshop of the project takes place at the Federal Institute for Materials Testing in Berlin. The subgroups present the first results and agree on the programming language Python for the exchange of code. Guest speakers are the Mercator Fellow of the research group Dr. Eric Larose giving a talk on Coda Wave Imaging, Dr. Christoph Völker on data fusion and PhD Sascha Liehr on fiber optics and neural networks.

The research unit visits the Center for Building Materials and Materials Testing at the Technical University of Munich and becomes familiar with the laboratories and equipment of the working groups concrete technology, chemistry, binders and additives as well as non-destructive testing. The concreting process with embedding of ultrasound, temperature and humidity sensors Sensors is demonstrated on the basis of a specimen batch. The group defines the transfer process measurement data to the database.

The DFG funded research unit CoDA, Concrete Damage Assessment by Coda Waves, meets for the kickoff of the project in Bochum. The groups present the work packages of the individual subprojects as well as the coordination project in detail, discuss the schedules and agree on the concept of data organization in an SQL database between the subprojects.. Furthermore, the newly hired employees introduce themselves.