| Popis: |
The paper introduces a new approach to magnify vibration responses of an object. In general, the higher the frequency of vibration, the lower the amplitude of displacement, so the response can be loaded by noise. The aim of this paper is to present practical application of the proposed approach in 3D digital image correlation method. This method uses two high speed cameras to measure displacements of the object. The phase-based motion magnification technique is used to magnify motion in captured image frames. Magnified frames are subsequently correlated to acquire displacement and deformation fields of the object. By this way, the amplified response is obtained. This approach also can be useful when the level of excitation is too low. The paper describes the experimental measurement that is based on the following procedure. As first the experimental modal analysis is performed and one of vibration mode is chosen for the further analysis. Thereafter, the object is excited using an acoustic exciter by harmonic signal with frequency of the chosen mode at two different amplitudes of excitation. The measurement with the higher level excitation is considered as the reference one. The responses acquired under the low level of excitation are subjected to the given procedure to magnify vibration motion. Results of both measurements are compared and commented. |
