Defining the domain and boundary conditions for finite element model of flexible road pavement

Abstract

The paper presents three methods for defining a finite cylindrical-type domain for finite element analysis of an elastic multi-layered half-space subjected to a rotationally symmetric vertical load distributed over a circular area, thus providing a mechanistic model of a flexible road pavement. For three sets of boundary conditions the methods ensure the consistency between the maximum deflection and the exact calculated value for a multi-layered half-space with compromising the accuracy of the key strain values. The first case uses standard support conditions at the finite element model boundaries – fixed in the direction perpendicular to that plane and sliding in the tangential direction. The other two cases use half-infinite elements – at the base and at the side wall of the domain. The first method, as an additional benefit, enables determining the exact value of the maximum deflection of pavement that can be used in the second and in the third of the described methods.