Statsenko, Tatiana; Chatziioannou, Vasileios and Kausel, WilfriedProceedings of the Third Vienna Talk on Music Acoustics (2015), pp. 153–157
Electronic speckle pattern interferometry (ESPI) has been implemented for investigation of the vibrational behavior of the Brazilian cuíca. An advanced filtering and processing of time-averaging ESPI data has been applied to a friction drum, which has not been studied by means of laser interferometry before. Asymmetry in the operating deflection shapes of the cuíca has been observed and discussed. The obtained results were compared to finite element method computer simulations and single-point laser Doppler vibrometer deformation measurements. Vibrational shapes of the cuíca occurring under harmonic excitation are presented along with corresponding simulated mode shapes followed by the discussion of irregular patterns. The results of ESPI show an agreement with simulations and provide quantitative data on absolute values of the deformation amplitude.