A DYNAMIC SYSTEM-IDENTIFICATION METHOD FOR THE CHARACTERIZATION OF THE RHEOLOGICAL RESPONSE OF A CLASS OF VISCOELASTIC MATERIALS

In this paper, a linear viscoelastic material is considered as a dynamic system. From this point of view, a dynamic system identification method is developed for the determination of the relaxation or creep function of the material from dynamic experimental measurements. First, the relationship between the relaxation or creep function and the frequency response function of the system is established by assuming a model of rational function of polynomials for the frequency response function. Second, a discrete-time system analysis method is introduced to identify the order and parameters of the model. Several numerical examples show that the proposed method is efficient and accurate.