Non parametric identification of the constitutive model of non-standard viscoelastic materials by means of dynamical measurements

Abstract

Abstract.A procedure for the identification of the constitutive model of non-standard materials is presented. The material constitutive equation is modeled with a generalized Kelvin model of n-order expressed in the form of a rational polynomial function in the frequency domain. A least square error formulation that makes use of orthogonal polynomials is employed to identify the model parameters from dynamical measurements made on test specimens. Dynamical mechanical measurements made on Polytetrafluoroethylene samples at variable excitation fixed frequency are used to test the devised fitting procedure. Fit results obtained by means of different model order are compared and discussed.