Numerical interconversion between linear viscoelastic material functions with regularization

In this paper, interconversion between linear viscoelastic material functions is studied emphasizing materials with relatively fast rate of relaxation. The aim of this paper is to study the whole material function determination process from a linear viscoelastic experiment to interconversion by taking into account non-ideal loading and noisiness of the data in such an experiment. No assumptions are made concerning the form of the relaxation modulus or the creep compliance. Interconversion is carried out by evaluating numerically the convolution integral. Three different yet similar approaches are studied. In numerical interconversion, the resulting matrix equation is ill-posed. Due to this, Tikhonov regularization is applied to solve the related matrix system. Numerical simulations indicate that reliable results can be obtained with proposed numerical procedures. (c) 2006 Elsevier Ltd. All rights reserved.