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CharacterizationofRoadTopographyandEffectsofSolidParticlesonWetAdhesionPropertiesofTread Reporter Tutor Professor 路面形貌表征及固体颗粒对轮胎湿附着性能的影响 汇报人 导师 教授 TheSourceofProject TheNationalNaturalScienceFunds Thestudyoftheeffectsofsolidparticlesonhydroplaningpropertiesoftireonwetroad Grantnumber 50908222 Content Chapter1 IntroductionChapter2 Thestudyofthree dimensionalcharacterizationofroadtopographyChapter3 Thestudyofhydroplaningmodeloftire roadChapter4 TheeffectsofsolidparticlesonwetadhesionpropertiesofthetireChapter5 Summaryandoutlook Introduction Whenacarrunningontheroughroad thefrictionbetweenthetireandtheroadtransfersavarietyofinteractionforcesbetweenthevehicleandtheroad Oncetheroadsurfaceiscoveredbywaterfilmwhichgeneratesdynamicallubricationonthecarrunningatahighspeed thewetadhesionpropertiesoftirewilldecrease andfinallyhydroplaningphenomenonwillhappen whichgreatlyreducethestabilityandsafetyofthecar Therefore theresearchabouttheskidresistanceoftire roadisofgreatpracticalsignification Hydroplaning Rainwaterflow Waterfilmgeneratesdynamicallubricationonthecarrunningatahighspeed thetireflowedup contactareareduced thewetadhesionpropertiesoftiredecreased Introduction Microandmacrotextureofasphaltpavement Roadistheexternalconditionsofvehicles directlyaffectsthetrafficsafety comfortandeconomy Roadmorphologyisgenerallyexpressedasthetextureofthepavementinthefieldofhighwayresearch Themicroandmacrotexturesofroadsurfacesignificantlyaffectthetire roadskidresistance Introduction Adoptappropriatesurfacemorphologyoftestingmethodsandequipment accuratelygettheroadmorphologyinformation andusesurfacemorphologyparameterstofullycharacterizetheroadsurfacemorphologywhichisnotonlybeneficialtothefunctionaldesignoftheroad butalsoprovideanimportanttheoreticalbasistothedesignoftire roadskidresistance Thecharacterizationofroadsurfacetopographyandtheeffectsofsolidparticlesonwetadhesionpropertiesoftreadwerestudiedinthispaper Researchstatus Theearlyresearchonhydroplaningandskidresistanceoftirewasmostlybasedontest toaboutthe1960s analyticalmethodsappeared Representatives Daughaday Browne Zmindar Ongandsoon Roadmorphologyplaysanimportantroleinroadskidresistance It sessentialtoselectappropriatesurfacemorphologycharacterizationparametersandmethods Commonmethods benchmarkparametermethod fractalmethod motifsmethodandwaveletanalysismethod Newmethods ISO25178parameters volumeparametersandconnectivityparameter Workofthispaper Inthestudyofthree dimensionalcharacterizationofroadsurfacetopography theATOSopticalscannerwasusedtoscantheroadsurfacetopographyinordertoobtaintheoriginalinformationandthenrelatedprocessingwascarriedout ThecharacterizationparametersofsurfacetopographywhichincludeISO25178parametersandconnectivityparameterswereusedtocharacterizethethree dimensionaltopographyofroad Bycontrollingtheroadsurfaceroughnessequallyaseriesofsimulatedroadsurfaceswhichincludehorizontalslot doubleslot chute doublechuteandisotropicslotwereconstructedtoanalyzetheeffectsofgroovetypeandsamplingintervalonthecharacterizationparametersofroadsurfacequantitatively Theperformanceoftheslidingandwearoftheroadwasalsoanalyzedindepth Inthestudyoftheeffectsofsolidparticlesonwetadhesionpropertiesoftread theeffectsofvolumeconcentrationofsolidparticlesinrainwaterwerefullyconsidered ahydroplaningmodelbasedonaverageflowequationwasdevelopedtosimulateviscoushydroplaningoftire tread andtheaffectsofhydrodynamicactionandsqueezeactionwerealsotakenintoaccount Thismodelcouldbeusedtoanalyzetheeffectsofsolidparticles externalloads initialheightandslidingspeedonwetadhesionperformanceoftirewithnumericaliterativesolutionsofFiniteDifferenceMethod Meanwhile verticaldeformationandpressuredistributionofthetreadunitalsowereanalyzedindepth Workofthispaper Thestudyofthree dimensionalcharacterizationofroadtopography 1 Collectionandprocessingofroadtopographyinformation Flowchartofcollectionandprocessingofroadtopographyinformation Restorediagramofroadmorphology Modulusdiagramofroadblock ATOSopticalscanner Collectionandprocessingofroadtopographyinformation 2 Simulationconstructofgroovedpavement Horizontalslot Doubleslot Thestudyofthree dimensionalcharacterizationofroadtopography Chute Doublechute Isotropicslot Simulationconstructofgroovedpavement 3 CharacterizationofroadtopographybyISO25178parameters ISO25178parameterforthecharacterizationofsurfacemorphologyisthelateststandarddevelopedbytheInternationalOrganizationforStandardization ISO ISO TSCD25178 2 2006 Heightparameters Sa Sq Sp Sv Sz Sku Sskandsoon Spatialparameters Sds Str Std Salandsoon Volumeparameters Vmp Vvv Vmc Vvcandsoon Comprehensiveparameters Sdr Sdqandsoon Thethree dimensionalcharacterizationofparametervaluesofroadmorphologycanbeobtainedAccordingtothedefinitionofISO25178parametersandrelatedmatlabprogram Thestudyofthree dimensionalcharacterizationofroadtopography Theactualroad CharacterizationofroadtopographybyISO25178parameters Theroughnessofordinarycementroadisabout1 8mm ISO25178parameterstableofgroovedroad Diagramofheightparameters samplinginterval CharacterizationofroadtopographybyISO25178parameters Diagramofvolumeparameters samplinginterval Diagramofheightparameters roadroughness DiagramofVmp roadroughness CharacterizationofroadtopographybyISO25178parameters DiagramofVmc roadroughness CharacterizationofroadtopographybyISO25178parameters DiagramofVvv roadroughness DiagramofVvc roadroughness 4 Characterizationofroadtopographybyconnectivity Theroadconnectivitytablewhensamplingintervalof0 5mm DiagramofE samplinginterval Thestudyofthree dimensionalcharacterizationofroadtopography TheroadconnectivitytablewhenSa 1 8mm DiagramofE roadroughness Characterizationofroadtopographybyconnectivity Horizontalslot Doubleslot Chute Doublechute Isotropicslot Actualroad Thestudyofhydroplaningmodeloftire road Physicalmodeloftire road Accordingtothehydrodynamiclubricationtheory ahydroplaningmodeloftire roadbasedontheaverageflowequationwasdevelopedtosimulateviscoushydroplaningoftiretread takingintoaccounttheaffectsofhydrodynamicactionandsqueezeaction Themodelprovidedatheoreticalbasisforthenextstepofthenumericalsolutionandsimulationanalysis Theaverageflowequationis Combinethefollowingformula Verticaldeformationformula Loadbalanceequation Asperitiesbearingequation Acompletemathematicalmodeloftire loadhydroplaningcouldbeconstructed andthusthenumericalanalysisofvariousfactorsonthewetadhesionpropertiesoftirewereconductedaswellasstressanddeformationdistribution Thestudyofhydroplaningmodeloftire road Theeffectsofsolidparticlesonwetadhesionpropertiesofthetire Duetothepresenceofabrasive sand dustandotherimpurities thewaterfilmontheroadwillinevitablycontainalargenumberofsolidparticles whichchangetheviscosity temperatureoftheliquidandotherphysicalcharacteristics AssumingthatthewaterviscosityisaffectedonlybysolidparticlesinthemodelEstablished andtheEinsteinformulaisexpressedas Where 0isthebasicviscosityoftheliquidandcisthevolumeconcentrationofsolidparticles 1 IntroductionofSolidparticles 2 Numericalcalculationprocess Flowchartofcalculatingprogram Theeffectsofsolidparticlesonwetadhesionpropertiesofthetire 3 Analysisofwetadhesionpropertiesoftread Variationoffilmthicknessatdifferentconcentrationofsolidparticles Theeffectsofsolidparticlesonwetadhesionpropertiesofthetire a F 5N b F 15N Variationoffilmthicknessatdifferentconcentrationofsolidparticlesanddifferentload Analysisofwetadhesionpropertiesoftread Variationoffilmthicknessatdifferentwedgeangle Variationoffilmthicknessatdifferentroughness Analysisofwetadhesionpropertiesoftread Variationoffilmthicknessatdifferentslidingvelocity Variationoffilmthicknessatdifferentinitialheight Analysisofwetadhesionpropertiesoftread 4 Analysisofverticaldeformationoftread a t 0 001ms b t 0 4ms Verticaldeformationcurveoftreadatdifferenttimes Theeffectsofsolidparticlesonwetadhesionpropertiesofthetire Verticaldeformationcurveoftreadatdifferentconcentrationofsolidparticles Verticaldeformationcurveoftreadatdifferentloads Analysisofverticaldeformationoftread 5 Analysisofpressureoftread a t 0 001ms b t 0 4ms Liquidpressureatdifferenttimes Theeffectsofsolidparticlesonwetadhesionpropertiesofthetire Liquidpressureatdifferentconcentrationofsolidparticles Analysisofpressureoftread Liquidpressureatdifferentloads Summaryandoutlook ThecharacterizationparametersofsurfacetopographywhichincludeISO25178parametersandconnectivityparameterswereusedtocharacterizethethree dimensionaltopographyofroad Analysisresultswillprovidesome