The Application of Micromechanical Modeling to Study the Non-Linear Behavior of Flexible Pavement under Truck Loading in Pakistan

Abstract

Abstract: This report presents the work done to create a 3D model of a pavement structure, which incorporates in a most accurately way non damaging effects of asphalt layer considering the different layers that compose the pavement structure. A series of approaches have been considered from linear viscoelastic modelling using Maxwell model via UMAT subroutine to integrated viscoelastic response using Prony series available in the built in ABAQUS material library. During this work also other effects have been considered including the viscoelastic behaviour caused by creep, which is included via a separate CREEP subroutine. In order to predict also the non-linear effect of viscous elastic response the well-known Schapery's nonlinear viscoelastic constitutive model was considered. Implementing 3D Schapery’s model can be done by using again user material subroutine UMAT. It was found that the use of a nonlinear viscoelastic model substantially transformed the pavement response. A series of python scripts have been developed to create a multi-step analysis to simulate a cyclic loading application. Keywords: Viscoelasticity, Abaqus. Asphalt, Damage, Simulation, Modelling, Pavement design