Study On Simulation Method Of Meso-cracking Of Asphalt Concrete

The purpose of this study is to establish a more effective and accurate mesoscopic asphalt mixture model to study its cracking problem.In this paper,two numerical modeling methods are used to analyze the cracking of asphalt mixture.The first is the random aggregate distribution and the embedded bond element finite element model.This method divides asphalt mixture into four important components: aggregate,asphalt mortar,interface transition zone and initial defect.Aggregate particles were simulated as randomly distributed polygons of different sizes according to the grading curves developed by Full and Thompson.Some effective methods are adopted to improve the success rate of aggregate delivery.For the initial defects,only the void was considered in this study.In the initial grid of asphalt mortar,zero-thickness viscous unit is inserted along the interface between aggregate and asphalt mortar to simulate the cracking process of concrete.The former cracking initial criterion and traction separation rule are modified to describe the failure behavior of bonded components.Based on the python language,a user-defined program for aggregate delivery,cohesive force unit insertion and modification of constitutive model construction was developed and embedded in abaqus,a commercial finite element software package.Compared with the experimental results,the validity and accuracy of the proposed meso-structure model are verified,and the effect of meso-structure on the macro performance of asphalt mixture is studied.The second method based on Voronoi polygon of the mesoscopic numerical model based on the rigid spring method and random on the circular aggregate by random aggregate delivering technology,then Voronoi grids were generated according to the aggregate centroid and a Voronoi unit grid boundary geometry for the interaction relationship between aggregate and bond between aggregate material is concentrated to aggregate the interface between the spring,defined by the thickness of the bonding material,The validity of the method is verified by two-dimensional and three-dimensional numerical uniaxial compression experiments.