Measurement of dynamic Poisson's ratio and the form factor for a cylindrical sample

A new method of determining the dynamic Poisson's ratio based on measuring the dynamic strain and shear deformations of two samples manufactured of the same material is proposed. One side of the sample is glued to a vibrating table, while the other to a load mass. A rate of the vibration accelerations of the sides and their phase lag are measured. A two dimensional model of the stress and shear sample deformations, in which the Poisson's ratio is an adjustable parameter, is developed. An algorithm based on joining the solutions for both the strain and the shear deformation in an optimal way to determine the Poisson's ratio is proposed. The measurements for samples of silicone rubber Silastic (R) S2 in frequency range from 10 Hz to 3KHz and temperatures from 30 to 70 degrees C were performed. Based on the developed two-dimensional numerical model form factors required to correct estimated modules of elasticity and loss tangents with a corresponding one-dimentional model were obtained. The numerical calculations were carried out for static and dynamic strain and shear deformations of a cylindrical sample. Empiric analytic formulas useful for practical applications in the range of Poisson's ratio at least from 0.3 to 0.495, radius-to-height ratio of the samples from 0.25 to 4.0 and the loss tangent from 0.1 to 0.5 as well as for a variety of modules of elasticity, densities and heights of the samples are proposed.