Numerical Simulation Of Asphalt Concrete Milling Process Based On Multicomponent Modeling

At present,there is still a big gap between the domestically developed road surface milling and planing machine and the same type of foreign products.All kinds of factors make the domestic road milling and planing machine lose a lot of competitiveness,so it is urgent to further improve the technical level of the domestic road milling and planing machine.As for the pavement milling machine,the key of its related technology research is to analyze the complex micromechanical properties of asphalt mixture,the interaction between coarse and fine aggregate and asphalt mortar,and to establish the finite element model of the working process of the milling cutter.In this paper,the finite element simulation software ABAQUS is used to build a micromechanical constitutive model close to the actual properties of asphalt concrete according to the physical properties of each component,and the finite element model of the interaction between asphalt concrete and milling cutter is established to obtain the resistance of the milling process.Under the condition of micromechanics,the average value of friction resistance is obtained.Especially when the cutter and aggregate particles contact the mechanical changes in the law.The main research contents of this paper are as follows:determine the tool's motion path and force during cutting,and then find the path equation of tool tip and the calculation formula of frictional resistance f;Furthermore,the relationship between friction resistance f and parameters such as feed speed v,cutting depth h and rotation speed n of milling planer was obtained.(1)Determine the movement path and force of the cutting tool in the cutting process,and then work out the trajectory equation of the tool tip and the calculation formula of friction resistance f;The relationship between the working parameters of friction resistance f is clarified.(2)From the perspective of micromechanics,the internal components of asphalt concrete are further refined.In the process of asphalt concrete specimen modeling,the micromechanics models of asphalt mortar and aggregate particles are respectively established,and the mechanical properties of aggregate particles and asphalt mortar are respectively set by Johnson-Cook model.The random feeding of aggregate particles in asphalt concrete samples was completed by using Python software and monte-carlo algorithm.Meshing process respectively using quadrilateral mesh and trilateral grid meshing of aggregate and asphalt mortar to represent two different mesoscopic material,including cutting material particles and asphalt mortar with fine grid,in other areas are using commongrid so as to ensure calculation precision at the same time as far as possible to reduce amount of calculation;Using the finite element analysis software ABAQUS to analyze the dynamics of the cutting tool under different working parameters,the cutting resistance along the feed direction and perpendicular to the feed direction can be obtained.The simulation results are imported into MATLAB to generate the change curve of tool friction resistance,so as to obtain the rule of its change with various factors,and according to the above rule,summarize the best working parameter combination of the milling and planing machine.(3)In the metal cutting process often use the tool surface coating method to reduce tool wear,try to apply the same way to the milling machine tool.Of asphalt mortar and aggregate particles of modeling method and conventional cutting is the same,coated tools is on the outer surface of the cutter head covering a layer of coating thickness is 4 ?m,then the coating knife base material parameters were set up after the coating and interface is defined as the first and second surface of a tool,the set of particles on asphalt mortar and aggregate respectively defined as the first and second surface,the coating on the outer surface and asphalt mortar and aggregate particle sets was defined as the surface of the first,second and third respectively;Because the tool matrix and coating are two different materials,so the use of two different grid division,respectively,the tool matrix using quadrilateral grid,coating using trihedral grid;You can submit the operation after completing the above steps.