sph 常用关键字手册

1.*CONSTRAINED_GLOBAL全局约束Purpose:Defineaglobalboundaryconstraintplane.定义一个全局平面边界约束TCTranslationalConstraint:平动约束EQ.1:constrainedxtranslation,EQ.2:constrainedytranslation,EQ.3:constrainedztranslation,EQ.4:constrainedxandytranslations,EQ.5:constrainedyandztranslations,EQ.6:constrainedxandztranslations,EQ.7:constrainedx,y,andztranslations,RCRotationalConstraint:转动约束EQ.1:constrainedx-rotation,EQ.2:constrainedy-rotation,EQ.3:constrainedz-rotation,EQ.4:constrainedxandyrotations,EQ.5:constrainedyandzrotations,EQ.6:constrainedzandxrotations,EQ.7:constrainedx,y,andzrotations.DIRDirectionofnormal正常的方向EQ.1:globalx,EQ.2:globaly,EQ.3:globalz.Xx-offsetcoordinatex方向偏移坐标Yy-offsetcoordinatey方向偏移坐标Zz-offsetcoordinatez方向偏移坐标Remarks:Nodeswithinamesh-size-dependenttoleranceareconstrainedonaglobalplane.Thisoptionisrecommendedforusewithr-methodadaptiveremeshingwherenodalconstraintsarelostduringtheremeshingphase.节点网格大小的依赖公差限制在全局坐标平面上，这个选项要求使用在适应的重新划分节点约束消失在重新划分阶段。举例说明：(多用在对称面处)*CONSTRAINED_GLOBAL*CONSTRAINED_GLOBAL151X平动Y、Z转动X法线方向343Z平动X、Y转动Z法线方向2.*SECTION_SPHSPH属性设置Purpose:DefinesectionpropertiesforSPHparticles.定义SPH粒子的属性SECIDSECIDisreferencedonthe*PARTcard.Auniquenumberorlabelnotexceeding8charactersmustbespecified.使用特定的PART编号，其号码字符不能超过8个字符。CSLHConstantappliedtothesmoothinglengthoftheparticles.Thedefaultvalueappliesformostproblems.Valuesbetween1.05and1.3areacceptable.Takingavaluelessthan1isinadmissible.Valueslargerthan1.3willincreasethecomputationaltime.Thedefaultvalueisrecommended.该常数用于设置光滑粒子长度，默认值应用于大部分问题。设定值在1.05~1.3之间是可行的，值小于1不可行，值大于1.3会增加计算时间，建议取默认值。HMINScalefactorfortheminimumsmoothinglength(SeeRemark1)设置最小光滑长度的比例因yxzzx子HMAXScalefactorforthemaximumsmoothinglength(SeeRemark1)设置最大光滑长度的比例因子SPHINIOptionalinitialsmoothinglength(overridestruesmoothinglength).ThisoptionappliestoavoidLS-DYNAtocalculatethesmoothinglengthduringinitialization.Inthiscase,thevariableCSLHdoesn'tapply.选择初始的光滑长度（覆盖初始的光滑长度），这个选项用于避免LS-DYNA在初始化过程中计算光滑长度。在这种情况下，CSLH的作用就会失效。DEATHTimeimposedSPHapproximationisstopped.SPH近似算法停止时间STARTTimeimposedSPHapproximationisactivated.SPH近似算法激活时间Remarks:1.TheSPHprocessorinLS-DYNAusesavariablesmoothinglength.LS-DYNAcomputestheinitialsmoothinglength,h0,foreachSPHpartbytakingthemaximumoftheminimumdistancebetweeneveryparticle.Everyparticlehasitsownsmoothinglengthwhichvariesintimeaccordingtothefollowingequation:)()(=))((νdivththdtdh(t)isthesmoothinglength,div(v)isthedivergenceoftheflow.Thesmoothinglengthincreaseswhenparticlesseparatefromeachotherandreduceswhentheconcentrationofparticlesisimportant.Itvariestokeepthesamenumberofparticlesintheneighborhood.Thesmoothinglengthvariesbetweentheminimumandmaximumvalues00*)(*hhHMAXthHMINDefiningavalueof1forHMINand1forHMAXwillresultinaconstantsmoothinglengthintimeandspace.1.SPH处理程序在LS-DYNA中使用变光滑长度。LS-DYNA计算初始光滑长度，h0，对于每一个SPH部分最小的距离在每个微粒之间。每个微粒都有它自己的光滑长度，随时间变化的方程如下：h(t)是光滑长度，div(v)是流动的散度。当粒子相互分离时光滑长度增加，3.*ELEMENT_SPHSPH单元Purpose:Definealumpedmasselementassignedtoanodalpoint.定义集中质量单元分配给一个节点NIDNodeIDandElementIDarethesamefortheSPHoption.节点编号和单元编号对于SPH要相同。PIDPartIDtowhichthisnode(element)belongs.节点或单元所属的PART组MASSMassvalue质量值4.*CONTROL_SPHSPH控制设置Purpose:ProvidecontrolsforcomputingSPHparticles为计算SPH粒子提供控制设置NCBSNumberofcyclesbetweenparticlesorting粒子分类搜索循环次数BOXIDSPHapproximationsarecomputedinsideaspecifiedBOX.WhenaparticlehasgoneoutsidetheBOX,itisdeactivated.Thiswillsavecomputationaltimebyeliminatingparticlesthatnolongerinteractwiththestructure.指定BOX内的SPH粒子参与计算。当某个SPH粒子位于BOX之外时，该粒子失效，通过消除某些不再与结构发生作用的粒子，可以节省计算时间。DTDeathtime.DetermineswhentheSPHcalculationsarestopped.粒子失效时间IDIMSpacedimensionforSPHparticles:SPH粒子的空间维数3for3Dproblems参数为3时，表示3维问题。2for2Dplanestrainproblems参数为2时，表示2维问题。-2for2Daxisymmetricproblems参数为-2时，表示轴对称问题。WhenavalueisnotspecifiedLS-DYNAdeterminesthespacedimensionautomaticallybycheckingtheuseof3D,2Dor2Dasisymmetricelements.当这个值无法自动指定LS-DYNA的维数，程序通过核对使用3维、2维或轴对称的单元来确定空间维数。MEMORYDefinestheinitialnumberofneighborsperparticle.Thisvariableisjustformemoryallocationofarraysduringtheinitializationphase.Duringthecalculation,someparticlescanrequestmoreneighborsandLS-DYNAwillautomaticallyadaptthesizeofthatvariable.Defaultvalueshouldapplyformostapplications.定义每个粒子的初始相邻粒子的数量，该变量只是在初始化阶段调整内存分配。在计算中，如果某些粒子需要更多的相邻粒子，LS-DYNA会自动调整该变量设置。默认值适用于大部分问题。FORMParticleapproximationtheory:粒子近似理论EQ.0:defaultformulation,默认公式EQ.1:remormalizationapproximation重归-近似化STARTStarttimeforparticleapproximation.ParticleapproximationswillbecomputedwhentimeoftheanalysishasreachedthevaluedefinedinSTART.粒子近似开始时间。当分析时间达到所设定的值时，粒子将开始计算。MAXVMaximumvalueforvelocityfortheSPHparticles.ParticleswithavelocitygreaterthanMAXVaredeactivatedSPH粒子速度最大值，如果速度超过该值，质点将会失效。CONTDefinesthecomputationoftheparticleapproximationbetweentwodifferentSPHparts:两个不同的SPH组之间粒子近似的计算设置。EQ.0:Particleapproximationisdefined(default)参数设为0计算粒子近似（默认值）EQ.1:Particleapproximationisnotcomputed.TwodifferentSPHmaterialswillnotinteractwitheachotherandpenetrationisallowed.参数设为1不计算粒子近似，两种不同的SPH材料不会发生相互作用，允许相互穿透。DERIVTimeintegrationtypeforthesmoothinglength:光滑长度的时间积分类型。3/1))()(