Study On Abrasion Resistance Of Hydraulic Machinery Materials Based On Homogenization Method

Energy is an important foundation for the survival and development of human society.At the same time,hydraulic machinery plays a vital role in China’s energy supply.Due to the particularity of China’s physical geography,there are different degrees of soil erosion in the whole country,which leads to the high sediment concentration in rivers,which leads to the adverse factors such as wear and cavitation,and puts forward higher requirements for physical properties such as wear resistance and thermal conductivity of hydraulic machinery’s flow parts.From the perspective of micromechanics,the homogenization method based on finite element method will be used to study the effects of different particle morphology parameters of periodic unit cell and representative volume cell on the effective properties such as linear elasticity,thermal conductivity and elastoplasticity of composite materials,and then evaluate the antiwear and anti-cavitation properties of hydraulic machinery overflow surface materials.The main research contents and achievements are as follows:(1)Study the influence of particle morphology on the linear elastic properties of composites: build reinforced particle composites and reinforced matrix composites,build the physical models of circular matrix PUC,square matrix PUC and square matrix RVE by using Digimat and Abaqus software,calculate the Zero boundary value,HS boundary value and theoretical values of bulk modulus and shear modulus of linear elastic properties,and compile subroutine for calculating bulk modulus and shear modulus based on KUBC and PBC boundaries in Z-set software under Linux system.It is found that when particles are reinforcements,increasing the volume fraction of particles and decreasing the aspect ratio of particles can effectively improve the bulk modulus and shear modulus of the composites,thus improving their strength and stiffness,and further improving their wear resistance.When the matrix is reinforced,reducing the volume fraction of particles and increasing the aspect ratio of particles can effectively improve the bulk modulus and shear modulus of the composite,thus improving its strength and stiffness,and further improving its wear resistance.(2)Study the influence of particle morphology on the thermal conductivity of composites:build thermal conductive particle composites and thermal conductive matrix composites,build physical models of circular matrix PUC,square matrix PUC and square matrix RVE by using Digimat and Abaqus software,calculate thermal analysis models such as Parallel model,Series model,Maxwell model and effective medium theory,and write subprograms to calculate thermal conductivity based on UGT and PTBC boundary in Z-set software under Linux system.Through the research,it is mainly found that: increasing the particle volume fraction and decreasing the aspect ratio of particles can effectively improve the thermal conductivity of the composites,thus reducing the oxidation effect of instantaneous high temperature on the overcurrent surface materials;In thermal conductive matrix composites,reducing the particle volume fraction and increasing the aspect ratio of particles can effectively improve the thermal conductivity of the composites,thus reducing the oxidation effect of instantaneous high temperature on the surface materials of the overcurrent.(3)Study the influence of particle morphology on the elastic-plastic properties of composites: ideal elastic-plastic particle composites and ideal elastic-plastic matrix composites are constructed.The physical models of round matrix PUC,square matrix PUC and square matrix RVE are established by using Digimat and Abaqus software,and the subprogram of calculating stress and strain is written in Z-set software under Linux system based on uniaxial tensile load.Through the research,it is found that when the particles are ideal elastic-plastic particles,increasing the particle volume fraction and decreasing the aspect ratio of particles in the plastic area can effectively reduce the internal stress of the composite material,enhance the elastic-plastic properties of the composite material,and thus improve the impact resistance of the hydraulic machinery overflow surface material.To sum up,it can be seen that the following two aspects can be taken to improve the antiwear and anti-cavitation performance of the surface materials of hydraulic machinery:(1)When the effective performance of particles is greater than that of the matrix,the particle volume fraction can be increased and the aspect ratio of particles can be reduced,and the composite made of PUC can be adopted;(2)When the effective performance of matrix is greater than that of particles,the aspect ratio of particles can be increased and the volume fraction of particles can be reduced,and the composite made of PUC can be adopted.