鍍鋅板電阻點(diǎn)焊質(zhì)量評(píng)判方法的研究.pdf

1、蘭州理工大學(xué)碩士學(xué)位論文鍍鋅板電阻點(diǎn)焊質(zhì)量評(píng)判方法的研究姓名：魏雷申請(qǐng)學(xué)位級(jí)別：碩士專業(yè)：材料加工工程指導(dǎo)教師：陳劍虹張鵬賢20090427鍍鋅板巾|陽點(diǎn)焊硪帚評(píng)劃的方法的研究AbstractWithgoodcorrosionresis協(xié)nce，galVaIlizedSteelsheethasbeenwidelyusedintheautomotiVemanufact嘶ngindust巧insteadofthecold—rolledpla

2、teHoweVer，t11eweIdabili夠ofgalVanizedSteelsheetinresistancespot、Ⅳeldingispoorbecauseofmezinccoatingwhichmakest11econtactareaoftheendoftheelectrodetipincre2Lse，andmecullrentdensityreduceMeanwhile，lowmeltingpointofzincresul

3、tsiIlseriousdamageoftheelectrodetipTherefore，thequali夠ofthejointofspotweldingistoounstabletocontmlAimingatttlequalitycontrolrequirementofspotweldingjointsofgalVanizedsteelsheetintheautomotivemanufact面ngindustry’weusedtll

4、esⅢfaceimagesofspot、ⅣeldingjointsandthedynanlicsigIlalwhichwepickedupreal—tiIIleintheprocessofspotweldingastheinfomlationsourceInordertodevelopalloIlline，non—destmctioIl，10wcoStdetectionmethodsofquali夠eValuation，、vec州edo

5、utsuchresearchesaSfollows：1SetupaplatfonlltocollectthesurfaceimagesofweldingjointsUnderthes鋤econdition，surfaceimagesofweldedjointsarecollectedbyusingthedigitalimagingtechnologyThepreprocessingofdigitalimagesshowsthatthes

6、urfaceimageofjointscanbeusedastllesourceofinfomation2Analyzethefeatureofthesurfaceimagesofanumberofspotweldingjoints；detellllinetheareaofdi虢rentcharacteristicregionasch2uracteristicpar鋤eterwhichcancharacterizethequali夠iI

7、訌onnationofSpotweldingAccordingtomereleVaIlceanalysisbetweentheareaofcharacteristicregionandtIleshearstrengtllof、Veldir培spot，selectthecharacteristicparameterwhichhassalientrelatiVi鑼austtleinputVectora11dtheshearingstreng

8、tlloft11ejointas也eoutputVectorSetupaBPneuralnet、Ⅳorkmodelwhichusestheshearstrengtllasanindicatorofqualit)revaluationThetestresultofnet、voIkmodelsho、^，smatitissuccessmltoevaluatemequali夠ofweldingspotonlinebyBPnetworkmodel

9、3Setupaplatfomwhichisamulti—ch秈elreal—timesynchronousacquisitiontocollectthedyn刪cinfomationsuchasweldingVoltage，weldingcurrent，andmedisplacementofelectrodewitlloutdiscrepancyintheprocessofresistancespotweldingSelectdynam

10、icresistanceandelectrodedisplacementasthesignalsourceofonlinequalityeValuation4ByanalyzingthesigIlalofdynamicresistanceandelectrodereplaCementin、Veldingprocess，abstractsomecharacteristicparameterswhicharerelevamwith、№ldi

11、ngprocessAccordingtothecorrelationanalysisbetweenfeatureparameterSaunldshearstTengthofjoints，seleCtthesecharacteriSticparameterSwhicharecloSelyrelatedtoshearstrengthofjointsastheinputVectorofsomnet、Ⅳork，andclassi匆andanal