Simulation Study On Milling Device Of Road Milling Machine Based On The Discrete Element Method

Along with our country economic development, coordinated development ofurbanization construction, focusing on the development of small towns, small andmedium-sized cities and super-large city are developing steadily.Under the new trendof urbanization, the demand of highway and city road maintenance is higher andhigher so that highway and city road maintenance work becomes increasingly heavy.Mechanized maintenance practices which are modern, intelligent and efficient will bethe desire of the people and the trend of the times. Road milling machine is one of themain road maintenance machinery. In our country, the application of milling planertechnology is relatively later,at the same time, the core technology, concrete cuttingtheory and related experience are also lack. In this paper, the milling device andmilling planer theory for road milling machine have been studied.This paper analyzed arrangement of the cutting tool and selection of the mainparameters of milling rotor which is one of the important parts of road millingmachine. The setting angle of the throw-out plate has been designed andcalculated.This paper expounds the structure and mechanism of asphalt mixture andfailure criterion of asphalt concrete as well as the kinematics analysis and forceanalysis of the cutting tool interaction with asphalt concrete.Based on the discrete element theory, the numerical model of asphalt concretestructure has been established and its parameters is calibrated by simulation ofuniaxial compression test and indirect tensile test using EDEM software. Five kindsof the road milling machine’s working conditions which are in simulation of themilling rotor from beginning to cut into the asphalt concrete to the road millingmachine stopping walking and it cleaning up the asphalt concrete broken material indrum housing have been discovered. By means of discussing each working conditioncharacteristics of asphalt concrete broken material instantaneous pass rate on the topof conveyor which is connected with drum housing, milling rotor instantaneous torque and axial force were to improve the theoretical study of milling process. This paperdiscussed the merits and demerits, milling planer operation performance between thetheoretical design milling rotor and improved-design milling rotor. The millingqualities affected by asphalt concrete broken material instantaneous pass, millingcutting properties and milling rotor axial force in simulations of different millingrotors with different axial angle which is the angle between left and right spiral lineswere analyzed.The milling drum housing static structure analysis was carried out onPatran/Nastran by using EDEM and FEM coupling analysis.The wear area of thecover of milling drum housing has been studied,which the area of the correspondingcalculation method was put forward.The disadvantages of traditional milling drumhousing front baffle-plate has been analyzed, and the rationality of improved structurewhich was put forward improving front baffle-plate was verified.