The NOSTRADAMUS begun with training on the high-speed camera by repeating the work on frequency-based triangulation for measuring 3D deflection shapes. In the studied part, the deflection shapes were improved by using the dense spatial information of the high-speed camera to improve the identification of material damping. To obtain the strain mode shapes, further processing was then performed in the frequency domain using linear elasticity theory. This work was disseminated as a journal publication, and it was presented on three conferences and a poster presentation.
Research on Vibration Fatigue based on the training course consisted of replicating two papers from the host on VF using modal decomposition and short-time estimation of VF life non-stationary loading. During the training, experimental tests were conducted on the laboratory test cases. Then, the short-time life estimation procedure was extended to measuring the vibration response of the structure with a high-speed camera instead of using the limited number of classical sensors (accelerometers like in the repeated research). To enable cycle counting in the frequency domain, the strain-mode-shapes identified with the high-speed camera were converted into stress-mode-shapes. In this process, a new method for modal identification was developed, which is suitable for modal identification from high-speed camera measurements. The developed method was based on the Fellow’s previous research, and it is transferred to the host. Developed method was disseminated in the journal publication, and it is developed as the opensource python package (MorletWaveModal) to allow easy exploitation by others. Also, the presentation of the method and the opensource effort was communicated via scientific conferences and YouTube video presentations. To convert the measured strain to stress a linear elasticity theory was used as implemented in the FEM model (developed from the CAD model of the structure). The FEM model was mixed with the experimentally obtained strain-mode shapes using a sub-structuring method. Cycle counting using the multiaxial VF criteria was performed only for the dominant modes leading to damage assessment.
