2、对圆柱体及单级台阶的圆柱体模具的高速压制成形过程进行二维数值模拟，直观显示压制过程中粉末的流动以及应力波的形成与传播过程。模拟结果表明：模具形状对应力波的波形有较大3影响；压制完成后，圆柱体压坯最大密度差为12 mg/cm，密度分布均匀且左右对称，压坯顶部和底部密度较中间部分密度稍大，与实验结果基本相似；圆柱体压坯中存在密度较低的横向窄带区域，揭示成形坯有可能形成分层或断裂。关键词：高速压制；格子Boltzmann方法；松弛函数；应力波中图分类号：TF12 文献标志码：ANumericalsimulation of powderflowin high velocity compac
3、tionbylattice BoltzmannmethodLIQiaojie,ZHENGZhoushun, WANGShuang,LIUJiankang(SchoolofMathematicsandStatistics,CentralSouthUniversity,Changsha410083,China)Abstract:Accordingtothe characteristics ofhigh velocitycompaction process,the rebound andreflection mixed boundarycondition wasused on the b
4、ottomand sides ofthe mould.By changing distribution function,akind ofboundarycondition which can simulate the dynamicprocess wasproposed.Arelaxation function wasestablished accordingtothe powderflowcharacteristicusinginitialand maximumdensity.Twodimensionalnumericalsimulations were given tocyl
5、indermould and single step cylindermould.Thedynamicevolution process ofpowders and the stress wave transformationprocesswerepresented.Theresultsindicatethatthe shapeofthemouldhas a greatinfluence onthe wave patternofstress.Thedensityofgreen compactis uniformlyand symmetricallydistributed,andth
6、egreatestdensity 3difference is 12 mg/cm.The top and bottomparts have slighthigherdensitythan the middlepart.These results are consistentwith the experimentalresults.Anarrowlowdensityband is found in the green compactwhich revealsthattheremayexistdensitystratification.Keywords:high velocitycom
