Contact-Models

ContactModels接触模型Acontactmodeldescribeshowelementsbehavewhentheycomeintocontactwitheachother.UsingtheInteractionpulldownmenuand+pick-list,youcanbuildalist(stack)ofcontactmodels.Thetopelementisappliedfirst,thenthenextonedownandsoon.Usetheupanddownbuttonstomovethecontactmodelupanddownthelist(checkthesectionsbelowsincesomemodelsneedtobeatthestartorendofthelist).Toremoveanitem,clickthexbutton.Clickthepreferencesbuttontoconfiguretheselectedmodel.（接触模型描述了元素间的接触行为。使用Interaction下拉列表和按钮“+”来添加一系列接触模型。EDEM优先采用列表中的最前列的接触模型，优先级依次下移。用户可以使用up和down按钮来上下移动列表中接触模型的排列。点击按钮“X’’来删除列表中的模型。点击Configure按钮来设置所选中接触模型的参数配置。）Everysimulationmusthaveatleastonebaseparticle-to-particleandoneparticle-to-geometrycontactmodel.EDEMissuppliedwithseveralintegratedcontactmodels;youcanalsoaddyourowncustomplug-incontactmodels.RefertotheusersectionoftheDEMwebsiteandtheEDEMProgrammingGuidefordetails.（所有仿真必须至少包含一个基础的颗粒-颗粒和颗粒-几何体接触模型。EDEM提供了几个可选的接触模型，你也可以添加自定义的接触模型插件。更多细节的查询可以到DEM用户网站查询）Hertz-Mindlin(noslip)（Hertz-Mindlin无滑动接触模型）Hertz-Mindlin(noslip)isthedefaultcontactmodel.（EDEM中默认的接触模型）Interaction相互作用ConfigurableParameters参数的设置PositionParticletoParticleNoneLastParticletoGeometryRecordRelativeWear(On/Off)TheRelativeWearmodelisawayofidentifyingregionsofhighimpact(normal)andabrasive(tangential)wearontheequipmentwithinasimulation.Itiscalculatedbasedontherelativevelocityandassociatedforcesbetweenthebulkmaterialandtheequipment.Thismodelprovidestheuserwithadditionaldatatoindicateregionsinwhichwearistakingplace.Whilstitprovidesquantitativevaluesforcomparisonbetweentwoormoredesigniterations,itdoesnotdetermineanexplicitmaterialremovalrate.相对磨损的记录（开/关）相对磨损是一种识别仿真中设备的高冲击（法向）和磨损（切向）区域的方法。这种方法是基于疏散物料与设备的相关力和相对速度计算的。这个接触模型提供用户额外的数据来表征相对磨损发生的区域。与此同时，这种计算方法提供了两次及两次以上的仿真设计数值的对比，但是并不能精确的计LastInteraction相互作用ConfigurableParameters参数的设置Position算材料的损失率。Note:TheRelativeWearmodeldoesnottakeintoaccountthesizeofeachelementsoalargevariationinmeshsizingmightproduceunexpectedorconfusingresults.注意：相对磨损模型不计每个单元的尺寸大小，因此网格尺寸如果变化很大可能会产生不可知和不可控的结果。Hertz-Mindlin(noslip)withRVDRollingFrictionHertz-Mindlin(noslip)withRVDRollingFrictioncalculatescontactforcesinthesamewayastheHertz-Mindlin(noslip)model,butoffersanalternativeimplementationofrollingfrictionsatcontacts.SincethismodelincludesHertz-Mindlin,removethedefaultno-slipcontactmodelfromthelist.Hertz-Mindlin(无滑动)滚动摩擦模型该接触模型计算接触力的方式与赫兹-梅德灵无滑动模型一样,但是在接触中它另外运用了滚动摩擦力。既然该模型包括赫兹-梅德灵模型，在接触列表中就需要移除默认的Hertz-Mindlin(无滑动)接触模型。InteractionConfigurableParametersPositionParticletoParticleNoneLastParticletoGeometryRecordRelativeWear(On/Off),seeHertz-MindlinLastHertz-MindlinwithArchardWear艾查德（Archard）磨损-赫兹-梅德灵接触模型Hertz-MindlinwithArchardWearmodelprovidestheuserwithanexplicitmeasurementofmaterialremovedfromexposedequipmentfacesduetosliding/abrasivewearduringabulkmaterialshandlingprocess.Itisbasedonthedeterminationofacalibrationconstantthatcanbedefinedthroughtheappropriatematerialtesting.该接触模型可以提供用户精确的测量在散装物料搬运与输送过程中产生的设备材料损耗。该模型的计算是基于材料物理实验的校准常数的测定。InteractionConfigurableParametersPositionParticletoGeometryAssignaWearConstantvalueforeachgeometrysection.RecordRelativeWear(On/Off),seeHertz-MindlinLastHertz-MindlinwithHeatConductionHertz-MindlinwithHeatConductioncalculatestheheatfluxbetweenparticlesincontact.Themodelcalculatesaheatfluxbasedontheparticletemperaturesandtheiroverlap.ThismodelmustbeusedwithUpdateTemperatureparticlebodyforcetocompletethecalculation.TheUpdateTemperatureparticlebodyforceallowstheinclusionofanexternalheatsourceandiswhereeachparticletemperatureiscalculatedbasedontheheatfluxcalculatedinthecontactmodelandagivenexternalheatflux.MakesuretheUpdateTemperatureparticlebodyforcemodelisaddedtotheparticlebodyforcemodel.SincethismodelincludesHertz-Mindlin,removethedefaultno-slipcontactmodelfromthelist.InteractionConfigurableParametersPositionParticletoParticleSetthethermalconductivityforeachtypeofparticle.Notetheunitdependsonthetemperatureunit;forexample,theunitwillbeW/mKwhenthetemperatureunitiskelvin.LastHertz-MindlinwithBonding（Hertz-Mindlin粘结模型）Hertz-MindlinwithBondingbondsparticlestogether.SincethismodelincludesHertz-Mindlin,youshouldremovethedefaultno-slipcontactmodelfromthelist.Touse,enablethebondingmodelforbothparticle-particleandparticle-geometryinteractions.Althoughparticlescannotbebondedtogeometryelements,thebondedmodelensuresthattheparticlescontactthegeometrybasedontheparticle’sphysicalradiusandnotthecontactradius.InteractionConfigurableParametersPositionParticletoParticle(alsoenableforParticletoGeometry)SelectanactivebondthensettheBondFormationTimeandthefollowingparameters:NormalStiffness:thetensile/compressivestiffnessalongthebond’sprincipalaxis（法向刚度）ShearStiffness:Shearstiffnessintheorthogonalplanetothebond’sprincipalaxis（切向刚度）CriticalNormalStress:themaximumnormalstressthebondcanwithstandbeforeitfails（法向临界应力）CriticalShearStress:Themaximumtangentialstressthebondcanwithstandbeforeitfails（切向临界应力）BondedDiskRadius:Theradiusofthecylindricalbondbetweentheparticles（粘结圆面半径）Setthebondstressandstiffnessvaluestorepresentthematerialthatisb