Dynamic Viscoelastic Analysis of Asphalt Pavements using a Finite Element Formulation

Abstract

ABSTRACT This paper studies the effect of time and load rate on the structural response of asphalt pavements when the surface layer is a linear viscoelastic material. A finite element incremental algorithm for dynamic analysis of viscoelastic solids is presented, where the stresses are computed using a hereditary integral in which the relaxation modulus is described by a Prony-Dirichlet series. The stresses are integrated in a semi-analytical form, whereas the dynamic equilibrium equations are integrated by the Trapezoidal Rule. Different pulse loads are considered and the viscoelastic responses of different asphalt layer thicknesses are compared. Several performance indicators typically utilized in pavement design are studied, particularly those at the surface layer, i.e., tensile stress and strain, shear strain, and surface deflection.