Simultaneous Identification of Two-Independent Viscoelastic Characteristics with the Virtual Fields Method

Abstract

In this study, a method for determining the viscoelastic material properties from displacement fields is proposed. Stress-strain relationship represented by the superposition integral is employed as the viscoelastic constitutive equation. Thus, the unknown properties are relaxation bulk and shear moduli. The virtual fields method based on the principle of virtual work is used as a method for the inverse analysis. The unknown material properties are determined by solving nonlinear simultaneous equations of the virtual work containing the constitutive equations. The validity of the proposed method is demonstrated by identifying the viscoelastic properties of a soft epoxy resin. Results show that the two independent viscoelastic material properties can be identified by proposed method.