Ground Vibration Test of the COSDYNA Wind Tunnel Model

Kurzfassung

Ground vibration tests were performed on the COSDYNA wind tunnel model at the DLR facilities in Göttingen on September 21st and September 27th, 2006. During the tests, the wind tunnel model was fixed to the ground. Hydraulic jacks were used to constrain the pitch motion of the wind tunnel model. These jacks can either be fully locked, or can be used to actively control the pitch motion of the wind tunnel model. Different configurations were tested to figure out the influence of the boundary conditions on the dynamic behaviour. Impact excitation was applied using an instrumented hammer at different excitation points to effectively excite all modes in the frequency range up to 400 Hz. Frequency response functions were acquired from impact testing and experimental modal analysis was carried out to extract the modal parameters from the measured data. This report comprises a brief description of the COSDYNA wind tunnel model together with a description of the different configurations tested. In addition, a summary is given of the results of the experimental modal analyses for the different configurations.