Research On Lightweight Method Of Mixing Vehicle Based On Discrete Element And Finite Element Co-simulation

The lightweight of concrete mixer plays an important role in energy saving and emission reduction and improving the competitiveness of enterprises.Due to the previous lightweight research,the CAE load of the mixing cylinder is mainly loaded by applying hydrostatic pressure or simplified force element under static condition,which cannot reflect the complex and changeable load of the mixing vehicle or the mixing cylinder under different motion states,and the effective quantitative analysis of the wear of the mixing cylinder due to long time operation.When the subframe is loaded by finite element method,the effect of the concrete center deviation is not taken into account,or only the horizontal deviation is considered,and a certain empirical value is set at the same time,which leads to the simulation error.Therefore,this paper proposes a new simulation method for the lightweight structure design of the agitator truck,and uses the discrete element and finite element co-simulation method to improve the simulation accuracy.The main work completed in this paper is as follows:(1)According to the focus of the research,a concrete discrete element model suitable for the research purpose of this paper is established.The discrete element model of concrete is simplified to coarse aggregate and mortar,and the contact parameters of the model are calibrated by virtual tests.At the same time,the geometric size of the mixing cylinder was kept consistent with the prototype,and only the diameter of concrete particles was increased.(2)The equivalent density is set in the concrete discrete meta-model.In this paper,the density of the concrete in the simulation model is studied in the simulation model,and the equivalent density is set,so as to ensure that the material of the model and the actual test is conserved by the mass,and the feasibility of the equivalent density setting is verified by the virtual experiment.(3)The discrete element and finite element co-simulation method was innovatively applied to the lightweight structure design of the mixing cylinder and the sub-frame,and the discrete element and finite element coupling model of the concrete mixer was established.A new technical route of discrete and finite element one-way coupling is proposed,and the accuracy of the coupling method is verified through experiments.The method can be used in the research of concrete with different strength levels and mixing trucks with different volume.(4)The discrete element method is applied to the abrasion of concrete mixing tube.Combined with stress strain and wear analysis,the light reduction method of reducing the thickness of the tank and blade was determined,and the weight loss was15.12%.(5)The simulation analysis of the mixing car of the concrete center is considered in the three direction migration,and the migration of the center of the concrete center and its motion trajectory are obtained.The effect of the deformation of the tank and the blade and the rotation state of the mixing drum was studied,and the simulation accuracy was improved.The new x structure of channel steel was designed,and the bending and anti-torsion ability of the auxiliary frame were improved,and the auxiliary frame of the long bar x structure was reduced by 4.08%,and the auxiliary frame of the original diagonal structure was reduced by 23.51%.