履带车辆的履带模型与分析-英文-

Vol.15No.12JOURNALOFSYSTEMSIMULATIONDec.20031774TrackModelandAnalysisofHigh-speedTrackedVehiclesHANBao-kun1,2,LIXiao-lei1,WANGChang-tian2(1SchoolofMechanismandVehicleEngineering,BeijingInstituteofTechnology,Beijing100081,China;2SchoolofMechanismandElectronicsEngineering,ShangdongUniversityofScienceandTechnology,Tai'an271000,China)Abstract:Trackedvehiclesrepresentacomplexdynamicalsystemprimarilyduetothepresenceofthetrack.Nowadaysresearchtothetrackedvehiclesmoreandmoreresortstosimulation.Trackmodelisakeyissueinthemodelingandsimulationoftrackedvehicles.Theprincipleoftwotypesoftrackmodelsispresentedthroughsystematicconsiderationoftrackdynamics,andtrack-terrain-roadwheelinteractions.AndaridemodeloftrackedvehiclesbasedonsoftwareplatformDADSisestablishedandtherideresponseoftrackedvehiclesisevaluatedandcomparedinconjunctionwithdifferenttrackmodels.Alsothereasonsofdifferentresponsesbetweentwotracksareillustrated.Theresultsofthestudyareutilizedtostudythepropertiesoftrackedvehiclebysimulation.Keywords:trackedvehicles;track;ridequality;modeling1,2121,100081;2,2710001004-731X(2003)12-1774-04TP391.9AIntroduction1Trackedvehicles,particularlymilitarybattletanksandarmoredpersonnelcarriers,aredesignedformobilityoverroughoff-roadterrains.Astrackedvehicleshavebecomemoresophisticatedandhenceexpensive,vehicledesignersareturningmoretocomputersimulationtechniquesinanefforttoevaluatetheridecomfortandsafety,toobtainoptimaldesignparameters,andtopredictandquantifytheeffectsofproposedchangeinthevehicleparameters[1].High-speedtrackedvehiclesconsistoftrackandsuspensioncomponentsandhullcomponents.Theformergroupincludesthetrack,road-wheels,idlerwheelsandsprocketwheels;thehullrepresentscollectivelyallremainingcomponentsofthevehicles.Inviewofanalyticalmodeling,atrackedvehiclerepresentsacomplexdynamicalsystemprimarilyduetothepresenceoftrack.Infact,theridedynamicmodelofatrackedvehicleisdevelopedsimilartoawheeledvehicle,however,consideringcertainmodificationswhichareuniquetothetrack.Forinstance,theenvelopingcharacteristicsofthetrack,wheelcatchingeffectsofthetrack,etc.contributeconsiderablytothevehicledynamicbehavior.2002-10-232003-04-05(C9667-2)(1971-),,,,,;,,,,,;,,,,Thispaperpresentstwotypesoftrackmodels,whicharedifferentfromthemodelingprinciples.Aridedynamicmodelisestablishedinordertovalidateandcomparethetwotrackmodels.Thecomparisonandresultsaregivenatthelastsectionofthepaper.1TrackModelsTrackconsistsofinterconnectedmetaltrackshoeswithsyntheticrubberpadsontheirinnerandoutersurfaces.Theinnerpadsprevent,wheneverpossible,metal-to-metalcontactduringtheshoes-wheelinteraction,andhelpreducethetrackandsuspensiondynamicloads.Similarly,theouterpadssoftentheshoes-groundinteraction,butmoreimportantly,theyprotectpavedroadsfromprematurewearduringvehicleoperationsoversuchsurfaces.Twotypesoftrackareusedextensivelyinmilitaryvehicles,thatis,thesingle-pintrackandthedouble-pintrack.Inordertodescribetherelationshipsbetweenthetrack,road-wheelandground,twotypesoftrackmodelsarepresented,thatisflexibletrackmodelandrigidtrackmodel,figure1.1.1FlexibletrackmodelThismodelregardsthetrackasaflexibleandinextensiblebelt.Therearethreepossiblestatesbetweenthetrack,road-wheelandground;(1)road-wheelisnotincontactwitheithertrackorground;(2)wheelisincontactwithtrack,buttrackisnotincontactwithground;(3)thewheelisincontactwithtrackandtrackisincontactwithground.Inthefirststate,noforcesareappliedtothewheel.Inthesecondstates,theforcesVol.15No.12Dec.2003,:1775Figure1trackmodelsappliedtothewheelsarethevectorsumofforcesinthetracksegmentsthatactonthewheel.Tensionisthesameonbothsidesofthetrack,asillustratedinfigure2(a).Thethirdmodeisthemostcomplex.Whenawheelisincontactwithtrackandtrackisincontactwithground,thegroundactuallyexertsnormalandshearforcesonthetrackandthetracktransmitstheseforcestothewheel.ConsideringthetracksegmentABshowninfigure2(b),thesumofforcesactingonthesegmentsyields∫∫+++=BABARLdsTTdsts00F(1)Wheres:Groundnormalforcest:Groundshearforces0LT0RT:TracktensionsFurtherqsin)(00RLnTTF+=)cos(sin2qqqt-=RFt(2)Givenequations(1)and(2),thetracktensions,normalandshearforcescanbecalculatedbytrackcatenaryequationsandterrainmechanics[2].1.2RigidtrackmodelInviewofrigidtrackmodel,thetackismodeledasaseriesofrigidbodiesconnectedbyrubberbushingsaroundthelinkpinswhichareinsertedintoashoesplatewithsomeradialpressureinordertoreducethenon-lineareffectoftherubber.Thetrackpadsareconnectedbyrevolutejoints,eachofwhichhasonedegreeoffreedomthatallowsrelativerotationbetweenthetwobodiesconnectedbythatjointaboutthejointaxis.Iftracklinkiisconnectedtotracklink1-ibyarevolutejointasshowninfigure3,thefollowingkinematicalconstraintshold12111---+=+iiiiii1,1--+=iiiiqqq(3)Whereiisthepositionvectoroftheoriginofthecoordinatesystemofbodyiwithrespecttotheoriginoftheglobalcoordinatesystem.iisthetransformationmatrixthatdefinetheorientationofbodyiwithrespecttothelocalcoordinatesystem.i1isthelocalpositionvectorofthejointdefinationpointdefinedinthecoordinatesystemofbodyi.iqistheanglethatdefinestheorientationofthecoordinatesyste