Desenvolvimento de um sistema gráfico para análise numérica de pavimentos asfálticos

Abstract

This paper presents the development of a pre-processor for the stress analysis of flexible pavements. The software, called PMG (Pavement Mesh Generator), generates axisymmetric meshes for the numerical analyses by the Finite Element Method (FEM). The software creates and draws the geometric model using a few data given by the user. These data include the characteristics of the pavement layers (e.g. hickness, material) and the applied load. Once the geometric model is finished, two types of mesh can be generated: a finite element mesh or a mixed mesh. The first one is created using only quadrilateral finite elements, while the other mixes quadrilateral finite elements with infinite elements. The software divides the pavement structure into regions in order to generate fine meshes near the load that is the region where there is a large stress concentration. The element size increases in a smooth manner as the region gets far away from the loaded region. The meshes generated using PMG are used in the FE analyses performed by the CAP3D system, which is a program developed by the Computer Modeling group of the Pavement Mechanics Laboratory (LMP/UFC). It is important to note that PMG generates meshes more quickly than other generic pre-processors as it is specific for pavement and requires a few input data. The use of infinite elements in the pavement analyses allows a decrease in the computational effort and a more realistic representation of the subgrade. Finally, in order to validate the system, numerical examples are presented comparing the stresses obtained using PMG and other pre-processors. The system is also used to study the effect of the discretization and the influence of the infinite elements on the FE response.