Asphalt Concrete Cutting Numerical Simulation Based On Discrete Element Method

The demand of maintenance machinery of road such as road milling machine isincreasing with the continuous development of highway. The working principle ofroad milling machine is cutting the damaged asphalt concrete pavement by using thebullet tool, then paving the new asphalt concrete. The asphalt concrete is a multiphasecomposite materials with viscoealasticity and rheological properties. The finiteelement has its inherent defect when dealing with incontinuum mechanics. Thecutting of asphalt concrete and cutting force of tools are simulated by numericalmethod of discrete element in this article. Analyzing the merit and demerit in discreteelement particle flow in2D and3D simulation of asphalt concrete cutting in thesoftware PFC, studying the change of cutting force in cutting tools of asphalt concretecutting. The rational and optimal working parameters are obtained and cuttingefficiency is increased. The main work in this article are as follows:1、Introducing the working principle of road milling machine and progress ofnumerical method in the study of asphalt concrete, introducing the advantages andbasic principles of discrete element particle Flow software (Particle Flow Code) onthe research of cutting asphalt concrete.2、The compressive strength and elastic modulus of the asphalt concrete areobtained by using the universal testing machine controlled by microcomputer forindoor experiment of asphalt concrete uniaxial compression.3、The2D and3D model of asphalt concrete are established on the basis ofmucilage principle of asphalt concrete, combining with the constitutive built-in modelof granular flow in software. Checking element model of asphalt concrete by buildingvirtual uniaxial compression test and split test, using built-in FISH language in theparticle flow software to write programs, calibrating its compressive strength, elasticmodulus, poisson’s ratio and tensile strength.4、2D cutting model of asphalt concrete imported to PFC2D is established byAutoCAD,3D cutting model imported to PFC3D is established by PRO/E. Simulatingthe cutting and analyzing the force of tool respectively, the conclusion is that thethree-dimensional cutting simulation is more suitable for simulation of bullet toolcutting of asphalt concrete and predicting the stress of the cutting tool.5、Firstly using single factor method and then using the orthogonal method to analysis the cutting force of bullet tool under the influence of cutting speed, cutting angle and cutting depth, the optimal cutting parameters are obtained as:Vc=5m/s, γ0=45°,ap=5mm.