apoordesign,highmaintenancecosts,shortconveyor-componentlifeandwellknownoperationalproblemslike:excessivelargedisplacementoftheweightofthegravitytake-updeviceprematurecollapseofthebelt,mostlyduetothefailureofthesplicesdestructionofthepulleysandmajordamageoftheidlersliftingofthebeltofftheidlerswhichcanresultinspillageofbulkmaterialdamageandmalfunctioningof(hydrokinetic)drivesystemsManyresearchlogyoftheFacultyofMechanicalEngineering,DelftUniversityofTechnology,oneofthethreeDutchUniversitiesofTechnology.--------Theinteractionbetweentheconveyorbeltproperties,thebulksolidsproperties,thebeltconveyorconfigurationandtheenvironmentallinfluencetheleveltowhichtheconveyor-systemmeetsitspredefinedrequirements.Someinteractionscausetroublesomephenomenasoresearchisinitiatedintothosephenomenawhichcausepracticalproblems,[].Onewaytoclassifytheseproblemsistodividethemintothecategorywhichindicatetheirunderlyingcausesinrelationtothedescriptionofbeltconveyors.---------Thetwomostimportantdynamicconsiderationsinthedescriptionofbeltconveyorsarethereductionoftransientstressesinnon-stationarymovingbeltsandthedesignofbelt-conveyorlay-outsforresonance-freeoperation,[].Inthispaperanewfiniteelementmodelofabelt-conveyorsystemwillbepresentedwhichenablesthesimulationofthebelt'slongitudinalandtransverseresponsetostartingandstoppingproceduresandit'smotionduringsteadystateoperation.It'sbeyondthescopeofthispapertodiscusstheresultsofthesimulationofastart-upprocedureofabelt-conveyorsystem,thereforeanexamplewillbegivenwhichshowsomepossibilitiesofthemodel。.FINITEELEMENTMODELSOFBELT-CONVEYORSYSTEMS--------Ifthetotalpowersupply,neededtodriveabelt-conveyorsystem,iscalculatedwithdesignstandardslikeDINthenthebeltisassumedtobeaninextensiblebody.ThisimpliesthattheforcesexertedonthebeltduringstartingandstoppingcanbederivedfromNewtonianrigidbodydynamicswhichyieldsthebeltstress.Withthisbeltstressthemaximumextensionofthebeltcanbecalculated.Thiswayofdeterminingtheelasticresponseofthebeltiscalledthequasi-static(design)approach.Forsmallbelt-conveyorsystemsthisleadstoanacceptabledesignandacceptableoperationalbehaviorofthebelt.Forlongbelt-conveyorsystems,however,thismayleadtoapoordesign,highmaintenancecosts,shortconveyor-componentlifeandwellknownoperationalproblemslike:excessivelargedisplacementoftheweightofthegravitytake-updeviceprematurecollapseofthebelt,mostlyduetothefailureofthesplicesdestructionofthepulleysandmajordamageoftheidlersliftingofthebeltofftheidlerswhichcanresultinspillageofbulkmaterialdamageandmalfunctioningof(hydrokinetic)drivesystemsManyresearch态凹陷比例常数是.，为.而带速Vb为.m/s。这个信号后期转化由如图所示快速傅里叶技术频谱获得。在图中出现了个频率。第一频率是由带结合处所引起：fs=Vb/L=.Hz第二个频率，出现在.赫兹，是由皮带横向振动所造成。图：带稳定移动时横向振动频率第三个频率出现在.Hz，是由托辊旋转所造成，从图所示数值模拟获得。图：计算共振区不同托辊直径D.贯穿实验表明皮带速度和托辊间距。图显示是拖过带与托辊互动引起共振区可以预测三个托辊直径。该带式输送机托辊直径为.M，从而可以预测皮带速度邻近.M/S共振现象。为了验证结果，在启动运输机时候测量了带最大横向位移跨度。图：测量横向振动和带静态凹陷幅度标准差比例。在图中，可以看出横向振动最大振幅发生在带速为.M/S处，正如有限元模型模拟预测结果一样。因此，带速度不应选择临近.米/s。虽然是用扁带进行实验和理论验证，但是这种应用技术也可运用于槽型带中。．结论带式输送机有限元模型中梁架元应用，带横向位移模拟，从而使能够设计出带无支撑共振。对于小数值来说，采用梁架元代替线性微分方程预测共振现象优势是同样可以预测到皮带纵向和横向位移之间相互作用以及从模拟中预见皮带脱离托辊。．参考文献.Lodewijks,G.(),"PresentResearchatDelftUniversityofTechnology,TheNetherlands",thInternationalConferenceonBulkMaterialStorage,Handlingandtransportation,Newcastle,Australia,-July,TheInstitutionofEngineers,AustraliaPreprintspp.-..Roberts,A.W.(),"AdvancesinthedesignofMechanicalConveyors",BulkSolidsHandling,pp.-..Nordell,L.K.andCiozda,Z.P.(),"Transientbeltstressesduringstartingandstopping:Elasticresponsesimulatedbyfiniteelementmethods",BulkSolidsHandling,pp.-..Funke,A.andKnneker,F.K.(),"Experimentalinvestigationsandtheoryforthedesignofalong-distancebelt-conveyorsystem",BulkSolidsHandling,pp.-..Harrison,A.(),"Flexuralbehaviouroftensionedconveyorbelts",BulkSolidsHandlingpp.-..Lodewijks,G.(),"Transversevibrationsinflexiblebeltsystems",DelftUniversityofTechnology,reportno...TT...Lodewijks,G.(),"OntheApplicationofBeamElementsinFiniteElementModelsofBeltConveyors,Part",BulkSolidsHandling,pp.-..Lodewijks,G.(),"TheRollingResistanceofBeltConveyors",BulkSolidsHandling,pp.-..Nordell,L.K.andCiozda,Z.P.(),"Transientbeltstressesduringstartingandstopping:Elasticresponsesimulatedbyfiniteelementmethods",BulkSolidHandling,pp.-.----------------------------------------logyoftheFacultyofMechanicalEngineering,DelftUniversityofTechnology,oneofthethreeDutchUniversitiesofTechnology.--------Theinteractionbetweentheconveyorbeltproperties,thebulksolidsproperties,thebeltconveyorconfigurationandtheenvironmentallinfluencetheleveltowhichtheconveyor-systemmeetsitspredefinedrequirements.Someinteractionscausetroublesomephenomenasoresearchisinitiatedintothosephenomenawhichcaus中文字TheTwo-DimensionalDynamicBehaviorofConveyorBeltsIr.G.Lodewijks,DelftUniversityofTechnology,TheNetherlands.SUMMARY--------Inthispaperanewfiniteelementmodelofabelt-conveyorsystemwillbeintroduced.Thismodelhasbeendevelopedinordertobeabletosimulateboththelongitudinalandtransversedynamicresponseofthebeltduringstartingandstopping.Applicationofthemodelinthedesignstageoflongoverlandbelt-conveyorsystemsenablestheengineer,forexample,todesignproperbelt-conveyorcurvesbydetectingprematureliftingofthebeltofftheidlers.Italsoenablesthedesignofoptimalidlerspacingandtroughingconfigurationinordertoensureresonancefreebeltmotionbydetermining(standing)longitudinalandtransversebeltvibrations.Applicationoffeed-backcontroltechniquesenablesthedesignofoptimalstartingandstoppingprocedureswhereasanoptimalbeltcanbeselectedbytakingthedynamicpropertiesofthebeltintoaccount..INTRODUCTION--------TheNetherlandshaslongbeenrecognisedasacountryinwhichtransportandtranshipmentplayamajorroleintheeconomy.TheportofRotterdam,inparticularisknownasthegatewaytoEuropeandclaimstohavethelargestharboursystemintheworld.Besidesthelargenumbersofcontainers,alargevolumeofbulkgoodsalsopassesthroughthisport.NotallthesegoodsareintendedfortheDutchmarket,manyhaveotherdestinationsandaretranshippedinRotterdam.Goodexamplesoftypicalbulkgoodsthataretranshippedarecoalandironore,asignificantpartofwhichisintendedfortheGermanmarket.Inordertohandlethebulkmaterialsawiderangeofdifferentmechanicalconveyorsincludingbelt-conveyorsisused.--------Thelengthofmostbelt-conveyorsystemserectedintheNetherlandsisrelativelysmall,sincetheyaremainlyusedforin-plantmovementofbulkmaterials.Thelongestbelt-conveyorsystem,whichisaboutkmlong,issituatedontheMaasvlakte,partoftheportofRotterdam,whereitisusedtotransportcoalfromabulkterminaltoanelectricitypowerstation.Inadditiontodomesticprojects,anincreasingnumberofDutchengineeringconsultanciesparticipatesininternationalprojectsforthedevelopmentoflargeoverlandbelt-conveyorsystems.Thisdemandstheunderstandingoftypicaldifficultiesencounteredduringthedevelopmentofthesesystems,whicharestudiedintheDepartmentofTransportTechnologyoftheFacultyofMechanicalEngineering,DelftUniversityofTechnology,oneofthethreeDutchUniversitiesofTechnology.--------Theinteractionbetweentheconveyorbeltproperties,thebulksolidsproperties,thebeltconveyorconfigurationandtheenvironmentallinfluencetheleveltowhichtheconveyor-systemmeetsitspredefinedrequirements.Someinteractionscausetroublesomephenomenasoresearchisinitiatedintothosephenomenawhichcausepracticalproblems,[].Onewaytoclassifytheseproblemsistodividethemintothecategorywhichindicatetheirunderlyingcausesinrelationtothedescriptionofbeltconveyors.---------Thetwomostimportantdynamicconsiderationsinthedescriptionofbeltconveyorsarethereductionoftransientstressesinnon-stationarymovingbeltsandthedesignofbelt-conveyorlay-outsforresonance-freeoperation,[].Inthispaperanewfiniteelementmodelofabelt-conveyorsystemwillbepresentedwhichenablesthesimulationofthebelt'slongitudinalandtransverseresponsetostartingandstoppingproceduresandit'smotionduringsteadystateoperation.It'sbeyondthescopeofthispapertodiscusstheresultsofthesimulationofastart-upprocedureofabelt-conveyorsystem,thereforeanexamplewillbegivenwhichshowsomepossibilitiesofthemodel。.FINITEELEMENTMODELSOFBELT-CONVEYORSYSTEMS--------Ifthetotalpowersupply,neededtodriveabelt-conveyorsystem,iscalculatedwithdesignstandardslikeDINthenthebeltisassumedtobeaninextensiblebody.ThisimpliesthattheforcesexertedonthebeltduringstartingandstoppingcanbederivedfromNewtonianrigidbodydynamicswhichyieldsthebeltstress.Withthisbeltstressthemaximumextensionofthebeltcanbecalculated.Thiswayofdeterminingtheela        中文6680字TheTwo-DimensionalDynamicBehaviorofConveyorBeltsIr.G.Lodewijks,DelftUniversityofTechnology,TheNetherlands1.SUMMARY1--------Inthispaperanewfiniteelementmodelofabelt-conveyorsystemwillbeintroduced.Thismodelhasbeendevelopedinordertobeabletosimulateboththelongitudinalandtransversedynamicresponseofthebeltduringstartingandstopping.Applicationofthemo

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