Analysis of Viscoelastic Parameters of Fluids by Low-Frequency Piezoelastography

Theoretical and experimental analysis of viscoelastic properties of fluids at low oscillating shear stresses was performed. Mathematic approach for calculating the complex coefficient of viscosity on the basis of experimental data on the amplitude-phase characteristics measured by the method of low-frequency piezoelastography was developed. The dependencies of the amplitude and phase shift of the signal recorded by a piezoelectric detector of a ARP-01M Mednord piezoelectric thromboelastograph on the frequency of forced oscillations of a resonator needle in air, water, and glycerin at fixed temperature of 37°C were studied. It was found that with increasing fluid viscosity, the resonance frequency of oscillations decreases in comparison with the frequency of oscillations in air.