Measurement of Dynamic Properties of Viscoelastic Materials

Abstract

An improved method to measure the dynamic viscoelastic properties of elastomers is proposed. The method is based on the analysis of forced oscillation of a cylindrical sample loaded with an inertial mass. No special equipment or instrumentation other than the ordinary vibration measurement apparatus is required. Upper and lower surfaces of the viscoelastic material sample were bonded to a load disc and a rigid base plate, respectively. The rigid base plate was subject to forced oscillations driven by a vibration exciter. Two accelerometers were attached to monitor the displacement of the base plate and the load disc. The recorded magnitude ratio and the phase difference between the load disc and the base plate vibrations represent the axial, dynamic deformation of the sample. The data are sufficient to obtain the dynamic properties of the sample, oscillation properties of vibration exciter, whereas the sensitivity of gauges having no effect on the calculation results. For accurate calculation of the properties, a two-dimensional numerical model of cylindrical sample deformation was used. Therefore, a form factor, which takes into account the sample sizes in one-dimensional models, is not required in this method. Typical measurement of the viscoelastic properties of a silicone rubber Silastic® S2 were measured over the frequency range from 10 Hz to 3 kHz under deformations (ratio of vibration magnitude to sample thickness) from 10 −4 % to 5%. It was shown that the modulus of elasticity and the loss tangent fall on a single curve when the ratio of load mass to sample mass changed from 1 to 20. When the sample diameter was varied from 8 to 40 mm, the modulus of elasticity fall on the same curve, but the loss tangent curves showed some degree of scatter. Studied temperature dependence and nonlinear behavior of viscoelastic properties is found not to be associated with this effect.

Influence of the thickness of monolithic compliant coatings on the skin friction drag

“…The experimental method to determine the viscoelastic properties of the coatings is described in detail [6,7]. It is based on measuring the vibration amplitude ratio and phase shift between two ends of cylindrical samples.…”

Evaluation of acoustic and dynamic behaviour of ethylene vinyl acetate panels

“…Werkstofftech. 2019, 50, [14][15][16][17][18][19][20][21][22][23][24] Increased sample thickness with a constant density led to greater sound transmission loss across the frequency range. However, the influence of sample thickness was less marked within the 2000 Hz-4000 Hz frequency range, where small sound transmission loss differences were observed.…”

“…Ther-moplastic materials, such as polyurethane and polypropylene, are a possible alternative to available sound-insulating materials [16][17]. Given the shock absorption and isolation properties of rubber compounds, several works have focused on determining dynamic stiffness and damping of these materials [18][19][20][21][22].…”

Measurement method of complex viscoelastic material properties

“…They are described in review of Ferry (1961) and recent example of Clifton et al (2006). The method of measurements of the modulus of elasticity and the loss factor used in Kulik and Semenov (1986), Kulik et al (2008) covers the frequency range from 10 to 10 kHz at relative values of deformation of orders 10 À4 % to 5%. The method is essentially easy-to-operate and reliable requiring no mechanical tuning and adjustment, the measurement results being independent from the vibrator characteristics.…”