Influence of Approximating Approach of Deformation Behavior on Viscoelasticity Evaluation of Soft Cellular Solids by Three-Element Solid Model

Abstract

Soft cellular solids like sponge and muscle have the nonlinear viscoelasticity due to the internal gas or liquid in cells and the behavior of the matrix of the solids. Their stress-time curves are different by the variation of their internal structures, and it causes difficulties in the evaluation of the mechanical characteristics of the solids. In this study, we adopted the multiplication form of power and exponent functions that is able to approximate the nonlinear and fluctuated behavior of soft cellular solids. Then, we examine the adequacy of this method by its application to the experimental results of tensile testings of SBR sponge and biological soft tissue. The results of the examination show that the adopted form of the functions have good ability to fit the complex results of the stress-time curves and it can realize good evaluation of viscoelasticity of soft cellular solid by using three-element solid model.