Alternative Function to Represent Relaxation Modulus of Viscoelastic Materials

Abstract

The generalized Maxwell model has been widely adopted for the prediction of relaxation modulus of viscoelastic materials, specifically asphalt materials. For practical reasons, relaxation modulus is rarely measured; instead it is predicted from creep compliance tests. In reality, the generalized Maxwell model is an approximate approach to simplify the process of inverting the Laplace transform of the Prony series function such that the computation process of obtaining relaxation modulus from creep compliance can become less complex. An alternative function can be derived to directly invert the Laplace transform of the Prony series function and predict relaxation moduli of viscoelastic materials. This paper presents a computation procedure on the basis of an alternative function that can be used to predict relaxation moduli of viscoelastic materials. The proposed model is capable of inverting the Laplace transform of the Prony series function and predicting the relaxation moduli of viscoelastic materials with only the component of one Maxwell model and one Kelvin element known as a Burger model. The algorithm presented in the proposed model is simple such that it can reduce the complexity of the computational process of inversing Laplace transform and generating Prony series parameters.