Determining the elastic constants of isotropic materials by modal vibration testing of rectangular thin plates

The paper presents a procedure whereby Poisson's ratio and the dynamic Young's modulus of isotropic and homogeneous materials are determined using two of the first four frequencies of natural vibration in thin rectangular plates. The procedure is based on suitable approximate relationships, relating the resonance frequencies to the elastic constants of the material. These relations were derived from those of Warburton by taking into account a correction factor obtained by an extensive series of numerical analyses carried out by a finite element code. In order to verify the procedure, a comparison with reference solutions has been made.