Automated real aggregate modelling approach in discrete element method based on X-ray computed tomography images

Abstract Numerical representations of aggregate particles are critical to reconstruct microstructure of asphalt mixtures. The main objective of this study is to obtain an accurate and automated discrete element method (DEM) with a small number of sphere elements for any real aggregate particle. An automated DEM method was developed based on X-ray computed tomography (CT) images with aid of computer graphics and image processing techniques. The method consists of three main steps. First, or each image layer, two-dimensional (2D) outlines of aggregate particles in cropped image blocks are detected. Second, the mapping between an aggregate particle and its outlines on different layers is established. Based on the aforementioned mapping, the three-dimensional (3D) geometric model of each particle is constructed. Third, the 3D geometric model of the aggregate particle is automatically transformed into its discrete element representation. For each aggregate particle, the fitting accuracy between the 3D geometric model and discrete element representation can be conveniently adjusted. The obtained clumps of spheres can be virtually assembled into the discrete element microstructure model of asphalt specimen and used in numerical simulation. Based on four aggregate particle templates, a single-edge notched beam model was reconstructed and the numerical fracture simulation was conducted. The simulation results indicated that the proposed modelling method is applicable to reconstruct asphalt mixture models and conduct performance test simulation.

[1]  Qingbin Li,et al.  Quantification and Simulation of Particle Kinematics and Local Strains in Granular Materials Using X-Ray Tomography Imaging and Discrete-Element Method , 2008 .

[2]  Qingli Dai,et al.  A micromechanical finite element model for linear and damage‐coupled viscoelastic behaviour of asphalt mixture , 2006 .

[3]  O. Portillo,et al.  Modeling Failure of Bitumen Films in Tension , 2012 .

[4]  John M. Boone,et al.  Development of a micromechanical finite element model from computed tomography images for shear modulus simulation of asphalt mixtures , 2012 .

[5]  Eyad Masad.  X-ray computed tomography of aggregates and asphalt mixes , 2004 .

[6]  Hoki Ban,et al.  Integrated Experimental–Numerical Approach for Estimating Material-Specific Moisture Damage Characteristics of Binder–Aggregate Interface , 2011 .

[7]  Zhanping You,et al.  Three-Dimensional Microstructural-Based Discrete Element Viscoelastic Modeling of Creep Compliance Tests for Asphalt Mixtures , 2011 .

[8]  F. Aragão,et al.  Modeling Rate-Dependent Fracture Behavior of Asphalt Mixtures , 2012 .

[9]  Jorge Barbosa Soares,et al.  Multiscale Modeling to Predict Mechanical Behavior of Asphalt Mixtures , 2010 .

[10]  Yu Liu,et al.  Viscoelastic Model for Discrete Element Simulation of Asphalt Mixtures , 2009 .

[11]  Yu Liu,et al.  Accelerated Discrete-Element Modeling of Asphalt-Based Materials with the Frequency-Temperature Superposition Principle , 2011 .

[12]  John B. Metcalf,et al.  Two-Step Approach to Prediction of Asphalt Concrete Modulus from Two-Phase Micromechanical Models , 2005 .

[13]  Habtamu Zelelew,et al.  Micromechanical Modeling of Asphalt Concrete Uniaxial Creep Using the Discrete Element Method , 2010 .

[14]  Robert S. Leiken,et al.  A User’s Guide , 2011 .

[15]  Zhanping You,et al.  Review of advances in micromechanical modeling of aggregate–aggregate interactions in asphalt mixtures , 2007 .

[16]  Qingli Dai,et al.  Integrated Experimental-Numerical Approach for Estimating Asphalt Mixture Induction Healing Level through Discrete Element Modeling of a Single-Edge Notched Beam Test , 2015 .

[17]  W. Buttlar,et al.  Thermal reflective cracking of asphalt concrete overlays , 2010 .

[18]  William G. Buttlar,et al.  Micromechanical fracture modeling of asphalt concrete using a single-edge notched beam test , 2009 .

[19]  T Harman,et al.  Characterization of aggregates and asphalt concrete using x-ray computerized tomography: a state of the art report , 2004 .

[20]  J. D. Frost,et al.  Microstructure Study of WesTrack Mixes from X-Ray Tomography Images , 2001 .

[21]  Mohd Rosli Mohd Hasan,et al.  Investigation of induction healing effects on electrically conductive asphalt mastic and asphalt concrete beams through fracture-healing tests , 2013 .

[22]  Qingli Dai,et al.  Prediction of Creep Stiffness of Asphalt Mixture with Micromechanical Finite-Element and Discrete-Element Models , 2007 .

[23]  Hyunwook Kim.  Investigation of Toughening Mechanisms in the Fracture of Asphalt Concrete Using the Clustered Discrete Element Method , 2007 .

[24]  Glaucio H. Paulino,et al.  Simulation of Crack Propagation in Asphalt Concrete Using an Intrinsic Cohesive Zone Model , 2006 .