Experimental analysis of vibration modes of plates using ESPI

In the world, there are several types of vibration, and these vibrations es pecially affect the mechanical industry. In this paper, experimental analys is of vibration modes of plates is discussed. Electronic speckle pattern in terferometry(ESPI) is one of the optical nondestructive testing techniques. By using the ESPI, vibration modes of plates with various excitation point s, ratio of longitudinal and lateral length, and materials are measured and qualitatively compared with the results of theoretical analysis proposed b y Warburton. Finally, these vibration modes are quantitatively compared wit h the result of FEM analysis. The results of this study are as follows: (1) By comparing the theoretical and experimental frequencies, we confirmed qu alitatively that deviations of frequencies are within 10% in accuracy. (2) By comparing the experimental vibration mode shapes with the numerical ones of the FEM analysis, we can conclude quantitatively that measuring vibrati on modes by using the ESPI has high accuracy.