会员注册 | 登录 | 微信快捷登录 支付宝快捷登录 QQ登录 微博登录 | 帮助中心 人人文库renrendoc.com美如初恋!
站内搜索 百度文库

热门搜索: 直缝焊接机 矿井提升机 循环球式转向器图纸 机器人手爪发展史 管道机器人dwg 动平衡试验台设计

外文翻译--振动故障分析中的微动磨损轴模拟器 英文版.pdf外文翻译--振动故障分析中的微动磨损轴模拟器 英文版.pdf -- 5 元

宽屏显示 收藏 分享

资源预览需要最新版本的Flash Player支持。
您尚未安装或版本过低,建议您

KeywordsFailureanalysisFrettingwearsimulatorVibratingshaftHightemperatureandhighpressurewaterFracturesurfaceminethefailureinitiationandfailuremode.Itwasfoundthatthefailurehadinitiatedataofthesenuclearfuelrods,whichhavethefollowingdimensions9.5mmouterdiameter,0.6mmwallthicknessandabouta4mlength.BecauseoftheFIVphenomenonbyaprimarycoolant,theseslenderfuelrodscouldeasilyvibrate,thustheyaresupportedbyseveralspacergridstructuresasshowninFig.1.Eachcellofaspacergridstructureconsistsoftwospringsandfourdimples.Therefore,anuclearfuelrodissupportedbyacertainamountofspringforce,whichdependsonthespringshapeanditsstiffness.UnderahightemperatureinanoperatingNPPcondition,however,thecontactforcebetweenthefuel13506307/seefrontmatterC2112008ElsevierLtd.Allrightsreserved.Correspondingauthor.Tel.8242688761fax82428630565.Emailaddressleeyhkaeri.re.krY.H.Lee.EngineeringFailureAnalysis1620091238–1244ContentslistsavailableatScienceDirectEngineeringFailureAnalysisdoi10.1016/j.engfailanal.2008.08.013temperatureC24320C176C,pressurizedwaterC2415MPaandradioactiveenvironment.Thisconditioninevitablyresultsinmaterialdegradationssuchasacorrosion,fatigue,irradiationembrittlement,creep,etc.duringtheiroperation.AnothersevereconditionfordegradingstructuralmaterialsisknownasaflowinducedvibrationFIVofrelativelyslenderstructuresduetotherapidflowvelocityofprimaryandsecondarycoolants,whichresultsinfrettingdamagesbetweentheseslenderstructuresandtheirsupportingstructures.ThesekindsoffrettingdamageshavebeenexperiencedinthemajorcomponentsofNPPssuchasthenuclearfuelrods,steamgeneratorSGtubesandcontrolrods1.Amongthesecomponents,inourlaboratory,thefrettingwearphenomenonofnuclearfuelrodshasbeeninvestigatedinordertoexamineanddevelopafrettingwearmechanismandadefectfreefuelassemblyFA,respectively.Generally,aFAconsistsof16C216or17C2171.IntroductionThefailurephenomenaofmechanicalfrequentlyinvariousindustries.Onecontactregionbetweenthevibratingshaftandthefuelrodholderjigandafatiguecrackwaspropagatedalthoughitwasdifficulttoproveitconclusivelyduetotheheavilyoxidizedfracturesurface.Nearthefailurelocations,however,thethreadholewassubjectedtoarepeatedloadingduetothefactthatthespecimenholderjighadacircularmotionforsimulatingavibrationmotion.ThissuggeststhatthevibratingshaftfailureresultedfromcorrosionfatiguephenomenonbecausethefrettingtesthadbeenperformedathightemperatureC24320C176CandpressurizeddistilledwaterC2415MPaconditions.Inthispaper,thereasonsforthisfailureandthefracturemechanismsarerevealedanddiscussedbyusingtheOMandSEMresultsofthefailuresurfaceandthestressanalysisofthecontactregionsbetweenthevibratingshaftandthespecimenholderjig.Finally,theaboveresultswereappliedtoadesignchangeofthevibratingshaft.C2112008ElsevierLtd.Allrightsreserved.structuresbymaterialdegradationsinextremeenvironmentshavebeenreportedexamples,isinnuclearpowerplantsNPPs.Generally,NPPsoperateinahighFailureanalysisofavibratingshaftinafrettingwearsimulatorYoungHoLee,JaeYongKim,HyungKyuKimKoreaAtomicEnergyResearchInstitute,150Dukjindong,Yuseonggu,Daejeon305353,RepublicofKoreaarticleinfoArticlehistoryReceived11July2008Accepted1August2008Availableonline15August2008abstractRecently,afrettingwearsimulatorwasdevelopedinordertoevaluatethefrettingwearbehaviorofnuclearcomponentsinhightemperatureandhighpressureHTHPwaterconditions.After500htests,however,twovibratingshaftsamongfourwerefractured,whichwereconnectedtoaspecimenholderjigbyusingabolt.ThefracturesurfacewasexaminedusingbothanopticalmicroscopeOMandascanningelectronmicroscopeSEMtodeterjournalhomepagewww.elsevier.com/locate/engfailanalY.H.Leeetal./EngineeringFailureAnalysis1620091238–12441239rodandspring/dimpleisgraduallydecreasedduetoaspringrelaxation.Inaddition,thespringstiffnessisalsograduallyincreasedbecauseofanirradiationembrittlementofaspacergridspring/dimple.Eventhoughacertainamountofspringforceisexertedonthefuelrodatitsinitialoperation,arelativelysmallslipamplitudeonthecontactsurfaceisunavoidableunderasevereFIVcondition.Consequently,thecontactforceisgraduallydecreasedandfinally,agapisopenedup.ThisFig.1.Theschematicviewofanuclearfuelassemblythatconsistsof16C216or17C217fuelrodsandseveralspacergridassembly.meansthatthefrettingwearmodecouldbechangedfromaslidingweartoanimpactingwearwithincreasingoperatingtime.Anotherimportantpointisthatthevibrationcharacteristicsofanuclearfuelrodalsochangedduetoacontactconditionchangeofafuelrod.Therefore,itisquitedifficulttoexaminethefrettingwearmechanismofanuclearfuelrodinNPPoperatingconditions.AverticaltypeofafrettingweartesterFRETONUS,FRTttingTesterOfNUclearSystemsforaHTHPwaterconditionwasdevelopedinordertoevaluatethefrettingwearbehaviorofnuclearcomponents2.After500htests,however,twovibratingshaftsamongfourwerefractured,whichwereconnectedtoaspecimenholderjigbyusingaboltasshowninFig.2.ItisFig.2.Schematicviewsoftheassemblingmethodbetweenthevibratingshaftandrodspecimenholderjigandthefracturedvibratingshaftafter500htestsathightemperatureandpressurizedwatercondition.essentialtoevaluatethereasonfortheirfailureandtoimprovethevibratingshaftdesigntoconfirmthereliabilityofthefrettingweartesterforalongexperiment.Inthisstudy,thereasonsforthefailureandthefracturemechanismsarerevealedanddiscussedbyusingtheOMandSEMresultsofthefracturesurface,measurementofthemicrovickershardnessandthestressanalysisofthevibratingshaft.Finally,theaboveresultswereappliedtoadesignchangeofthevibratingshaft.2.Fracturesurfaceanalysis2.1.OMobservationThevibratingshaftismadeofaconventionalhighcarbonmartensiticstainlesssteelSUS440Candthismaterialiswidelyusedastoolsorbladesforuseinrelativelycorrosiveatmospheres3.ThechemicalcompositionandmechanicalpropertiesarelistedinTable.1.Fig.3showstheOMresultofthefracturesurfaceforthevibratingshaft.DuetotheHTHPwatercondition,thefracturesurfacewasheavilyoxidizedanditwasdifficulttoobtainmetallographicproofbyusingtheOMobservation.However,itisexpectedthatthefailurewasinitiatedatacontactregionbetweenthevibratingshaftandthefuelrodholderjigbecausethesetwopartswasassembledbyusingaboltasshowninFig.2.Duringthefrettingweartests,fourvibratingshaftswerereciprocatedintheiraxialdirectionwitharangeof±200lm,afrequencyof30C176Hzandasinusoidalmotionbytwoelectromagneticactuatorsthatwerearrayedatanangleof90o.TogenerateacircularmotionofthefuelrodspecimenwhichisregardedasaconservativesimulationofanactualfuelrodvibrationinoperatingNPPs,thephasedifferenceofthesinusoidalwaveformfortheshakesignalsoftwoactuatorsissetto90oasshowninFig.4.Whenthefuelrodspecimenisvibratedwithacircularmotion,thecontactregionofthevibratingshaftswiththefuelrodholderjigisexpectedtoexperiencefatigueloads.Generally,striationtracesthataredistinctproofforafatiguefailurecouldbefoundeasilyonafracturesurface,ifthestructuralmaterialsarefracturedunderthefatigueloadingconditions.However,theoxidizedfracturesurfaceofthevibratingshaftwasexaminedbyusingSEMwithoutanycleaningsbecausethestriationtracescouldbeexpectedtoremovebytheoxideremovalprocessi.e.acidcleaning.2.2.HardnessvariationBeforetheSEMobservation,itisnecessarytoexaminethemechanicalpropertychangesofthevibratingshaft,becauseitwasexposedtotheHTHPwaterconditionduring500htests.So,amicrovickershardnessofthefracturedvibratingshaft1240Y.H.Leeetal./EngineeringFailureAnalysis1620091238–1244wasmeasuredanditsresultisshowninFig.5.Itisapparentthatthemicrovickershardnessvalueincreasedaccordingtotheexposedtemperatureforthevibratingshaft.ThisresultcorrespondswellwiththetemperingtemperatureeffectTable1ChemicalcompositionsandmechanicalpropertiesroomtemperatureofaconventionalhighcarbonmartensiticstainlesssteelSUS440C4CMnSiPSCrMoFeChemicalcompositionswt1.01.01.00.040.03170.75Bal.YieldstrengthTensilestrengthElongationElasticmodulusDensityPoissonsratioMechanicalproperties1280MPa1750MPa4200GPa7.8g/cm30.3Fig.3.OMresultofthefracturesurfaceforthevibratingshaftarrowsindicatetheexpectedcrackinitiationregion.Y.H.Leeetal./EngineeringFailureAnalysis1620091238–12441241Fig.4.ActuatingmechanismofthefuelrodbyusingtwoelectromagneticactuatorsinFRETONUSnotethatthefuelrodmotionsarechangeablebyadjustingvibrationamplitudesandphasedifferencebetweentwoactuators.onthemechanicalpropertiesofSUS440C4.Inthisstudy,thehighercarbonmartensiticstainlesssteelislikelytoretainalargeamountofuntransformedaustenite.Itisthoughtthatadelayedtransformationmayoccurastemperaturefluctuationsinseveralfrettingweartestsbecausethe500htestsatabout320C176Cdidnothaveanegligibleeffectonthestressrelievingofthevibratingshaftmaterial.Inaddition,itispossiblethatsomelossinductilitymayresultfromahydrogenembrittlementthatisanimportantconcerninmartensiticstainlesssteelsinaheattreatingatmospherecontaininghydrogenintheformofdistilledwater.2.3.SEMresultsFig.6showsthemorphologyofthefracturesurfacebyusingSEM.Itisapparentthatthefracturesurfacewasalmostcoveredwithoxidesanditisdifficulttodetectevidenceofafatiguefailuresuchasstriationtraces.Fromacarefulinspectionoftheresults,however,weakstriationtracesappearednearalateraloutersurface.Also,acrackpropagationtracewasfoundatthecontactregionbetweenthevibratingshaftandthefuelrodholderjigeventhoughitscharacteristiccouldnotbedefinedduetothesevereoxidationintheHTHPwatercondition.Oneoftheinterestingresultsisthatanimpactingwearscarappearedinthefracturesurfaceofthevibratingshaft.Thisresultmeansthattheimpactingwearbetweenthetwofracturedsurfacesisgeneratedafterafracturebecausethefracturedvibratingshaftiscontinuouslyreciprocatedbyanelectromagneticactuatorregardlessoftheshaftfailure.So,itisexpectedthatthefatiguestriationtraceshaddisappearedandwerecoveredbytheimpactingwearmotionandbytheweardebriswithasevereoxidation,respectively.Consequently,thevibratingshaftfailureisexpectedtobeinitiatedbyacontactfatigueatthecontactregionandthenthecontactforceexertedbyaboltFig.5.Measurementresultofthemicrovickershardnessaccordingtotheexposedtemperatureforthevibratingshaft.
编号:201311171144036007    大小:2.05MB    格式:PDF    上传时间:2013-11-17
  【编辑】
5
关 键 词:
教育专区 外文翻译 精品文档 外文翻译
温馨提示:
1: 本站所有资源如无特殊说明,都需要本地电脑安装OFFICE2007和PDF阅读器。图纸软件为CAD,CAXA,PROE,UG,SolidWorks等.压缩文件请下载最新的WinRAR软件解压。
2: 本站的文档不包含任何第三方提供的附件图纸等,如果需要附件,请联系上传者。文件的所有权益归上传用户所有。
3.本站RAR压缩包中若带图纸,网页内容里面会有图纸预览,若没有图纸预览就没有图纸。
4. 未经权益所有人同意不得将文件中的内容挪作商业或盈利用途。
5. 人人文库网仅提供交流平台,并不能对任何下载内容负责。
6. 下载文件中如有侵权或不适当内容,请与我们联系,我们立即纠正。
7. 本站不保证下载资源的准确性、安全性和完整性, 同时也不承担用户因使用这些下载资源对自己和他人造成任何形式的伤害或损失。
  人人文库网所有资源均是用户自行上传分享,仅供网友学习交流,未经上传用户书面授权,请勿作他用。
0条评论

还可以输入200字符

暂无评论,赶快抢占沙发吧。

当前资源信息

4.0
 
(2人评价)
浏览:18次
英文资料库上传于2013-11-17

官方联系方式

客服手机:13961746681   
2:不支持迅雷下载,请使用浏览器下载   
3:不支持QQ浏览器下载,请用其他浏览器   
4:下载后的文档和图纸-无水印   
5:文档经过压缩,下载后原文更清晰   

相关资源

相关资源

相关搜索

教育专区   外文翻译   精品文档   外文翻译  
关于我们 - 网站声明 - 网站地图 - 友情链接 - 网站客服客服 - 联系我们
copyright@ 2015-2017 人人文库网网站版权所有
苏ICP备12009002号-5