简介:Numericalsimulationconcerningtheformingandweldingprocessofspiralweldedpipewasconducted,whichincludedthreesteps:thefirststepwasthestressanalysiswhenthespiralwasformed,andthenthestresswasregardedasinitialconditionofmeldingduringthetemperaturefieldanalysisintheprocessofwelding,thelaststepwasthethermalstressanalysisoftheweldseamaftertheweldingwasover.Moreover,whenthesteelstripwaspushed,thestresswasalsocalculatedbynon-linearitycontacttechnologyusingAbaqusSoftware.Byfiniteelementmodelingandcalculatingoftheformingandweldingprocessofthespiralweldedpipe,thekeypointsofthemulti-fieldssyntheticsimulatingwerestudiedanddiscussed.
简介:Wastewaterfromproductionprocessof2,3-acidwastreatedbyadsorptionusingmacroporousresinNDA-708.Afteronlyone-steptreatmentbyresinadsorption,removalefficiencyofthreekindsofnaphthalenechemicalswasabove99%;removaleficiencyofCODcrwasabove96%.Underproperoperatingcondition,desorptionefficiencywasaround100%.Therunningrecordsoftheindustrialfacilityshowedthatthenaphthlenechemicalsindesorptioneffluentcouldbereusedwithoutobviousinfluenceonthequalityoftheproduct.
简介:Byusingageneralizedfitness-dependentMoranprocess,anevolutionarymodelforsymmetric2×2gamesinawell-mixedpopulationwithafinitesizeisinvestigated.Inthemodel,theindividuals’payoffaccumulatingfromgamesismappedintofitnessusinganexponentfunction.Bothselectionstrengthβandmutationrateεareconsidered.Theprocessisanergodicbirth-deathprocess.Basedonthelimitdistributionoftheprocess,wegivetheanalysisresultsforwhichstrategywillbefavouredwhenεissmallenough.Theresultsdependonnotonlythepayoffmatrixofthegame,butalsoonthepopulationsize.Especially,weprovethatnaturalselectionfavoursthestrategywhichisrisk-dominantwhenthepopulationsizeislargeenough.Forarbitraryβandεvalues,the’Hawk-Dove’gameandthe’Coordinate’gameareusedtoillustrateourmodel.Wegivetheevolutionarystablestrategy(ESS)ofthegamesandcomparetheresultswiththoseofthereplicatordynamicsintheinfinitepopulation.Theresultsaredeterminedbysimulationexperiments.
简介:stabilityofweldingprocessistheprerequisiteandassuranceforidealjoint.Thestructureofstabilitymodelanditsoptimizationarethekeytoon-lineevaluationtechnologyofarcwelding.Characteristicparametersareextractedfromthesingletransferperiodwhilevariationcoefficientsofthecharacteristicparametersareconcernedforwholeweldingprocessofcontinuousdroptransfer.Basedonthecharacteristicparametersandtheirvariationcoefficients,stabilitymodelofshort-circuitarcweldingprocessisestablishedbypartial-least-squareregression(PLSR)thatcanovercomemulticollinearityofinputparameters.Theexperimentresultsshowthatthismodelcanmeettherequirementofaccuracy.
简介:Hourglassisremarkablyarousedinringrollingsimulationwithreducedintegrationelementbecauseofviolentringvibrationandsmallcontactareaofringwithformingrollers.Hourglassenergycanbereducedbyimprovingmeshdensity.Combinedapproachofartificialdampingandartificialstiffnesscancontrolthehourglass.Aringwithrectangularsectionissimulatedwiththeweightfactorofartificialstiffnessresistancesetto0.2.Theartificialdampinghourglasscontrolcoefficientissetto0.1,andtheartificialstiffnesshourglasscontrolcoefficientissetto0.001.Theratioofhourglassenergytointernalenergyisreducedto2.5percent.Comparedwithaxialspreadwidthtest,theeffectivenessofhourglasscontrolinringrollingsimulationisverified.
简介:Arecursiveidentificationmethodisproposedtoobtaincontinuous-timestate-spacemodelsinsystemswithnonuniformlysampled(NUS)data.Duetothenonuniformsamplingfeature,thetimeintervalfromonerecursionsteptothenextvariesandtheparameterisalwaysupdatedpartiallyateachstep.Furthermore,thisidentificationmethodisappliedtoformacombineddatacompressionmethodinNUSprocesses.Thedatatobecompressedarefirstclassifiedwithrespecttoaseriesofpotentiallyexisting(possiblytime-varying)models,andthenmodeledbytheNUSidentificationmethod.Themodelparametersarestoredinsteadoftheidentificationoutputdata,whichmakesthefirstcompression.Subsequently,asthesecondstep,theconventionalswingingdoortrendingmethodiscarriedoutonthedatafromthefirststep.Numericresultsfromsimulationaswellaspracticaldataaregiven,showingtheeffectivenessoftheproposedidentificationmethodandfoldincreaseofcompressionratioachievedbythecombineddatacompressionmethod.
简介:Asadepositiontechnology,gasmetalarcwelding(GMAW)hasshownnewpromiseforrapidprototypingofmetallicparts.DuringtheprocessofmetalformingusingthearcofGMAW,lowheatinputandstabledroplettransitionarecriticaltohighqualityfiguration.TheeffectsofvariousprocessingparametersonfigurationqualitywerestudiedintheexperimentofGMAWrapidprototypingusingthewireofER50-6,includingweldingvoltage,wirefeedingrate,weldingspeedandsoon.TheoptimalparametersforER50-6areobtained.Simultaneously,itisverifiedthattherapidprototypingpartswithfavorablestructuresandqualitycanbeachievedundertheconditionsoflowheatinputandstabledroplettransition.
简介:ResearchofpatterndynamicsparametersofcrustaldeformationfieldinseismogenicprocessShuo-YuZHOU(周硕愚),YunWU(吴云),Ruo-BoWANG(王若柏)and...