Evaluating the Viscoelastic Behavior of Elastomers Using a Piezoelectric Tactile Sensor and an Optimization Approach

Elastomers, polymers, and human tissues are well-known viscoelastic materials whose behavior are hard to grasp. Several mathematical models, being linear and nonlinear, have been proposed to describe the elastic and viscous properties of viscoelastic materials. In this paper, we aim to characterize the dynamic properties of silicon rubber viscoelastic material with different mixing ratios. To this end, an experimental setup using a piezoelectric cantilever was used to apply force to the viscoelastic specimens, and an eddy current sensor was used to measure the displacement. We used the Standard Linear Solid (SLS) model and the hysteresis loop methods to formulate the relations between applied force, displacement, damping, and stiffness. Furthermore, an optimization approach was proposed to find the SLS model parameters by searching functions over the frequency domain. The obtained results agree with the related research. In addition, our approach differentiated between the tested specimens depending on damping and stiffness dynamic properties. The results have shown that the damping of the PDMS tested specimes decreases with increasing the frequency and the harder the elastomer the more damping it shows. Also, the stiffnesses of the SLS model increase by increasing the frequency and by increasing the hardness of the elastomer.