Morphological simplification of asphaltic mixture components for micromechanical simulation using finite element method

Computer-Aided Civil and Infrastructure Engineering, vol. 36, pp. 1435–1452

Abstract

In micromechanical simulations of asphalt mixtures, complex shapes of asphalt mortar and coarse aggregates require numerous elements in the finite element (FE) representation. This makes simulation time-consuming with a high risk of failure. To conduct simulations with acceptable accuracy and low computational cost, an approach is proposed to simplify the geometry of mixture microstructures with error assessment due to simplification. The methodology comprises four main steps, as follows: (1) coarse aggregates in a specimen are three-dimensionally reconstructed to conduct surface triangulation; (2) surface triangles are then clustered with a predefined fitting accuracy using the least square method; (3) coarse aggregates are simplified as polyhedrons based on triangle clusters, and the asphalt mortar is then reconstructed using Boolean operations; and (4) the simulation error caused by simplification is assessed based on FE interpolation theory to ensure the reliability of the simulation. Two samples were prepared and then reconstructed for the simulation of a cyclic indirect tensile test. The volume difference for more than 95% aggregates was less than 5% for the two specimens. The difference of stress and strain curves of original and simplified models of the two specimens ranged from 2% to 4%, which indicates that the simulation solutions of the simplified and original microstructures were very close. Furthermore, computational time was significantly reduced due to the simplification of the aggregates. This method facilitates the reliable and highly efficient simulation of asphalt mixtures using the FE method.

Authors 5

1. Can Jin

   Hefei University of Technology

   Affiliation as printed

   School of Automotive and Transportation Engineering, Hefei University of Technology, Hefei, Anhui, China

2. Wuxing Zhang

   Hefei University of Technology

   Affiliation as printed

   School of Automotive and Transportation Engineering, Hefei University of Technology, Hefei, Anhui, China

3. Pengfei Liu corresponding Aachen Institute of Highway Engineering

   RWTH Aachen University

   Affiliation as printed

   Institute of Highway Engineering, RWTH Aachen University, Aachen, Germany

4. Xu Yang

   Chang'an University · Monash University

   Affiliation as printed

   Department of Civil Engineering, Monash University, Melbourne, Australia

   School of Highway, Chang'an University, Xi'an, China

5. Markus Oeser Aachen Institute of Highway Engineering

   RWTH Aachen University

   Affiliation as printed

   Institute of Highway Engineering, RWTH Aachen University, Aachen, Germany