DETERMINATION OF THE ELASTIC CONSTANTS OF MATERIALS, IN THE FORM OF PLATES, BY A FREE VIBRATION METHOD

Abstract The problem of characterizing thin layer ceramic deposited by plasma spraying has led the authors to develop an original means to determine materials, elastic constants by using a free vibration method. This paper gives an overview of an experimental set-up used for the elastic properties measurement of a free circular plate at room temperature or at higher temperature (1000 °C). This method is based on analysis of the natural frequencies of vibration recorded by a microphone. Identification of experimental natural frequencies and modal parameters that characterize the mode shapes, calculated analytically by using Mindlin theory, enables the Young's modulus and Poisson ratio of the material tested to be determined. Analytical and experimental results are compared over a frequency range from 0 to 20 kHz.