外文翻譯-龍門式起重機金屬材料的疲勞強度預測

畢業(yè)設計中英文翻譯英文原文FATIGUELIFEPREDICTIONOFTHEMETALWORKOFATRAVELLINGGANTRYCRANEVAKOPNOVABSTRACTINTRINSICFATIGUECURVESAREAPPLIEDTOAFATIGUELIFEPREDICTIONPROBLEMOFTHEMETALWORKOFATRAVELINGGANTRYCRANEACRANE,USEDINTHEFORESTINDUSTRY,WASSTUDIEDINWORKINGCONDITIONSATALOGYARD,ANSTRAINMEASUREMENTSWEREMADEFORTHECALCULATIONSOFTHENUMBEROFLOADINGCYCLES,THERAINFLOWCYCLECOUNTINGTECHNIQUEISUSEDTHEOPERATIONSOFASAMPLEOFSUCHCRANESWEREOBSERVEDFORAYEARFORTHEAVERAGENUMBEROFOPERATIONCYCLESTOBEOBTAINEDTHEFATIGUEFAILUREANALYSISHASSHOWNTHATFAILURESSOMEELEMENTSARESYSTEMATICINNATUREANDCANNOTBEEXPLAINEDBYRANDOMCAUSES卯1999ELSEVIERSCIENCELTDALLRIGHTSRESERVEDKEYWORDSCRANESFATIGUEASSESSMENTSTRAINGAUGING1INTRODUCTIONFATIGUEFAILURESOFELEMENTSOFTHEMETALWORKOFTRAVELINGGANTRYCRANESLT62BAREOBSERVEDFREQUENTLYINOPERATIONFAILURESASFATIGUECRACKSINITIATEANDPROPAGATEINWELDEDJOINTSOFTHECRANEBRIDGEANDSUPPORTSINTHREEFOURYEARSSUCHCRANESAREUSEDINTHEFORESTINDUSTRYATLOGYARDSFORTRANSFERRINGFULLLENGTHANDSAWNLOGSTOROADTRAINS,HAVINGALOADFITTINGCAPACITYOF32TONSMORETHAN1000CRANESOFTHISTYPEWORKATTHEENTERPRISESOFTHERUSSIANFORESTINDUSTRYTHEPROBLEMWASSTATEDTOFINDTHEWEAKESTELEMENTSLIMITINGTHECRANESFIVES,PREDICTTHEIRFATIGUEBEHAVIOR,ANDGIVERECOMMENDATIONSTOTHEMANUFACTURERSFORENHANCINGTHEFIVESOFTHECRANES2ANALYSISOFTHECRANEOPERATIONFORTHEANALYSIS,ATRAVELINGGANTRYCRANELT62BINSTALLEDATLOGYARDINTHEYEKATERINBURGREGIONWASCHOSENTHECRANESERVESTWOSAWMILLS,CREATESALOGSTORE,ANDTRANSFERSLOGSTOOROUTOFROADTRAINSAROADPASSESALONGTHELOGSTORETHESAWMILLSAREINSTALLEDSOTHATTHERECEPTIONSITESAREUNDERTHECRANESPANASCHEMATICVIEWOFTHECRANEISSHOWNINFIG113506307/99/一SEEFRONTMATTER1999ELSEVIERSCIENCELTDALLRIGHTSRESERVEDPIIS1350一63079800041一7ASERIESOFASSUMPTIONSMAYBEMADEAFTEREXAMININGTHEWORKOFCRANESIFTHEMONTHLYREMOVALOFLOGSFROMTHEFORESTEXCEEDSTHEPROCESSINGRATE,IETHEREISACREATIONOFALOGSTORE,THECRANEEXPECTSWORK,BEINGABOVETHECENTREOFAFORMEDPILEWITHTHEGRABLOWEREDONTHEPILESTACKWHENPROCESSINGEXCEEDSTHELOGREMOVALFROMTHEFOREST,THECRANEEXPECTSWORKABOVEANOPERATIONALPILECLOSETOTHESAWMILLWITHTHEGRABLOWEREDONTHEPILETHESTOREOFLOGSVARIESTHEHEIGHTOFTHEPILESISCONSIDEREDTOBEAMAXIMUMTHESTOREVARIATIONTAKESPLACEFROMTHESIDEOPPOSITETOTHESAWMILLTHETOTALVOLUMEOFAPROCESSEDLOADISONTHEAVERAGEK14TIMESMORETHANTHETOTALVOLUMEOFREMOVALBECAUSEOFADDITIONALTRANSFERS21REMOVALINTENSITYITISKNOWNTHATTHEREMOVALINTENSITYFORONEYEARISIRREGULARANDCANNOTBECONSIDEREDASASTATIONARYPROCESSTHESTUDYOFTHECHARACTEROFNONSTATIONARYFLOWOFROADTRAINSAT23ENTERPRISESSVERDLESPROMFORFIVEYEARSHASSHOWNTHATTHEMONTHLYREMOVALINTENSITYEVENFORONEENTERPRISEESSENTIALLYVARIESFROMYEARTOYEARTHISISEXPLAINEDBYTHECOMPLEXOFVARIOUSSYSTEMATICANDRANDOMEFFECTSWHICHEXERTANINFLUENCEONREMOVALWEATHERCONDITIONS,CONDITIONSOFROADSANDLORRYFLEET,ETCALLWOODBROUGHTTOTHELOGSTORESHOULD,HOWEVER,BEPROCESSEDWITHINONEYEARTHEREFORE,THELESSPOSSIBILITYOFREMOVINGWOODINTHESEASONBETWEENSPRINGANDAUTUMN,THEMOREINTENSIVELYTHEWOODREMOVALSHOULDBEPERFORMEDINWINTERWHILEINWINTERTHEREMOVALINTENSITYEXCEEDSTHEPROCESSINGCONSIDERABLY,INSUMMER,INMOSTCASES,THEMOREFULLLENGTHLOGSAREPROCESSEDTHANARETAKENOUTFROMTHEANALYSISOF118REALIZATIONSOFREMOVALVALUESOBSERVEDFORONEYEAR,ITISPOSSIBLETOEVALUATETHERELATIVEREMOVALINTENSITYGTASPERCENTAGESOFTHEANNUALLOADTURNOVERTHEREMOVALDATAFISTEDINTABLE1ISCONSIDEREDASEXPECTEDVALUESFORANYCRANE,WHICHCANBEAPPLIEDTOTHEESTIMATIONOFFATIGUELIFE,AND,PARTICULARLY,FORANINSPECTEDCRANEWITHWHICHSTRAINMEASUREMENTWASCARRIEDOUTSEELATERITWOULDBEPOSSIBLEFOREACHCRANETOTAKEADVANTAGEOFITSLOADTURNOVERPERONEMONTH,BUTTOESTABLISHTHESEDATAWITHOUTSPECIALSTATISTICALINVESTIGATIONISDIFFICULTBESIDES,TOSOLVETHEPROBLEMOFLIFEPREDICTIONAKNOWLEDGEOFFUTURELOADSISREQUIRED,WHICHWETAKEASEXPECTEDVALUESONCRANESWITHSIMILAROPERATIONCONDITIONSTHEDISTRIBUTIONOFREMOVALVALUEQTPERMONTHPERFORMEDBYTHERELATIVEINTENSITYQTISWRITTENASWHEREQISTHEANNUALLOADTURNOVEROFALOGSTORE,AISTHEMAXIMALDESIGNEDSTOREOFLOGSINPERCENTOFQSUBSTITUTINGTHEVALUEQ,WHICHFORTHEINSPECTEDCRANEEQUALS400,000M3PERYEAR,ANDA10,THEVOLUMESOFLOADSTRANSFERREDBYTHECRANEAREOBTAINED,WHICHARELISTEDINTABLE2,WITHTHETOTALVOLUMEBEING560,000M3FORONEYEARUSINGK,22NUMBEROFLOADINGBLOCKSTHESETOFOPERATIONSSUCHASCLAMPING,HOISTING,TRANSFERRING,LOWERING,ANDGETTINGRIDOFALOADCANBECONSIDEREDASONEOPERATIONCYCLELOADINGBLOCKOFTHECRANEASARESULTTOINVESTIGATIONS,THEOPERATIONTIMEOFACYCLECANBEMODELEDBYTHENORMALVARIABLEWITHMEANEQUALTO115MINANDSTANDARDDEVIATIONTO15MINUNFORTUNATELY,THISCHARACTERISTICCANNOTBESIMPLYUSEDFORTHEDEFINITIONOFTHENUMBEROFOPERATIONCYCLESFORANYWORKPERIODASTHELOCALPROCESSINGISEXTREMELYIRREGULARUSINGATOTALOPERATIONTIMEOFTHECRANEANDEVALUATIONSOFCYCLEDURATIONS,ITISEASYTOMAKELARGEERRORSANDINCREASETHENUMBEROFCYCLESCOMPAREDWITHTHEREALONETHEREFORE,ITISPREFERREDTOACTASFOLLOWSTHEVOLUMEOFAUNITLOADCANBEMODELEDBYARANDOMVARIABLEWITHADISTRIBUTIONFUNCTIONTHAVINGMEAN22M3ANDSTANDARDDEVIATION6一3M3,WITHTHENOMINALVOLUMEOFONEPACKBEING25M3THEN,KNOWINGTHETOTALVOLUMEOFAPROCESSEDLOADFORAMONTHORYEAR,ITISPOSSIBLETODETERMINEDISTRIBUTIONPARAMETERSOFTHENUMBEROFOPERATIONCYCLESFORTHESEPERIODSTOTAKEADVANTAGEOFTHEMETHODSOFRENEWALTHEORY1ACCORDINGTOTHESEMETHODS,ARANDOMRENEWALPROCESSASSHOWNINFIG2ISCONSIDERED,WHERETHERANDOMVOLUMEOFLOADSFORMSAFLOWOFRENEWALSINRENEWALTHEORY,REALIZATIONSOFRANDOM，HAVINGADISTRIBUTIONFUNCTIONFT,AREUNDERSTOODASMOMENTSOFRECOVERYOFFAILEDUNITSORREQUESTRECEIPTSTHEVALUEOFAPROCESSEDLOAD，AFTERTHOPERATIONISADOPTEDHEREASTHERENEWALMOMENTLETFTPTTHEFUNCTIONFTISDEFINEDRECURRENTLY,NLETVTBETHENUMBEROFOPERATIONCYCLESFORATRANSFERREDVOLUMETINPRACTICE,THETOTALVOLUMEOFATRANSFERREDLOADTISESSENTIALLYGREATERTHANAUNITLOAD,ANDITISUSEFULTHEREFORETOTAKEADVANTAGEOFASYMPTOTICPROPERTIESOFTHERENEWALPROCESSASFOLLOWSFROMANAPPROPRIATELIMITRENEWALTHEOREM,THERANDOMNUMBEROFCYCLESVREQUIREDTOTRANSFERTHELARGEVOLUMETHASTHENORMALDISTRIBUTIONASYMPTOTICALLYWITHMEANANDVARIANCEWITHOUTDEPENDENCEONTHEFORMOFTHEDISTRIBUTIONFUNCTION月TOFAUNITLOADTHERESTRICTIONISIMPOSEDONLYONNONLATTICEOFTHEDISTRIBUTIONEQUATION4USINGTABLE2FOREACHAVERAGEDOPERATIONMONTH,FUNCTIONOFNUMBEROFLOADCYCLESWITHPARAMETERSM,AND6,WHICHNORMALDISTRIBUTIONINTABLE3FIGURE3SHOWSTHEAVERAGENUMBERSOFCYCLESWITH95CONFIDENCEINTERVALSTHEVALUESOFTHESEPARAMETERSFORAYEARAREACCORDINGLY12,719AND420CYCLES3STRAINMEASUREMENTSINORDERTOREVEALTHEMOSTLOADEDELEMENTSOFTHEMETALWORKANDTODETERMINEARANGEOFSTRESSES,STATICSTRAINMEASUREMENTSWERECARRIEDOUTBEFOREHANDVERTICALLOADINGWASAPPLIEDBYHOISTINGMEASUREDLOADS,ANDSKEWLOADINGWASFORMEDWITHATRACTORWINCHEQUIPPEDWITHADYNAMOMETERTHEALLOCATIONSCHEMESOFTHEBONDEDSTRAINGAUGESARESHOWNINFIGS4AND5ASWASEXPECTED,THELARGESTTENSIONSTRESSESINTHEBRIDGETAKEPLACEINTHEBOTTOMCHORDOFTHETRUSSGAUGE1145MPATHETOPCHORDOFTHETRUSSISSUBJECTEDTOTHELARGESTCOMPRESSIONSTRESSESTHELOCALBENDINGSTRESSESCAUSEDBYTHEPRESSUREOFWHEELSOFTHECRANETROLLEYSAREADDEDTOTHESTRESSESOFTHEBRIDGEANDTHELOADWEIGHTSTHESESTRESSESRESULTINTHEBOTTOMCHORDOFTHEI一BEAMBEINGLESSCOMPRESSEDTHANTHETOPONEGAUGE1775AND1020MPATHEOTHERELEMENTSOFTHEBRIDGEARELESSLOADEDWITHSTRESSESNOTEXCEEDINGTHEABSOLUTEVALUE45MPATHEELEMENTSCONNECTINGTHESUPPORTWITHTHEBRIDGEOFTHECRANEARELOADEDALSOIRREGULARLYTHELARGESTCOMPRESSIONSTRESSESTAKEPLACEINTHECARRYINGANGLESOFTHEINTERIORPANELTHEMAXIMUMSTRESSESREACHH0MPAGAUGES8AND9THELARGESTTENSIONSTRESSESINTHEDIAPHRAGMSANDANGLESOFTHEEXTERIORPANELREACH45MPACAUSES1ANDHLTHEELEMENTSOFTHECRANEBRIDGEARESUBJECTED,INGENERAMAXIMUMSTRESSESANDRESPONDWEAKLYTOSKEWLOADSTHESUHAND,ARESUBJECTEDMAINLYTOSKEWLOADS1,TOVERTICALLOADSPPORTSOFTHECRANEGMMGRISETOONTHEOTHERTHELOADINGOFTHEMETALWORKOFSUCHACRANE,TRANSFERRINGFULLLENGTHLOGS,DIFFERSFROMTHATOFACRANEUSEDFORGENERALPURPOSESATFIRST,ITINVOLVESTHELOADCOMPLIANCEOFLOGPACKSBECAUSEOFPROGRESSIVEDETACHMENTFROMTHEBASETHEREFORE,THELOADINGINCREASESRATHERSLOWLYANDSMOOTHLYTHESECONDCHARACTERISTICPROPERTYISTHELOWPROBABILITYOFHOISTINGWITHPICKINGUPTHISISCONDITIONEDBYTHEPRESENCEOFTHEGRAB,WHICHMEANSTHATTHEFALLOFTHEROPEFROMTHESPREADERBLOCKISNOTPERMITTEDTHELOADSHOULDALWAYSBEBALANCEDTHEPOSSIBILITYOFSLACKBEINGSUFFICIENTTOACCELERATEANELECTRICDRIVETONOMINALREVOLUTIONSISTHEREFOREMINIMALTHUS,THEFORESTTRAVELINGGANTRYCRANESARESUBJECTEDTOSMALLERDYNAMICSTRESSESTHANINANALOGOUSCRANESFORGENERALPURPOSESWITHTHESAMEHOISTINGSPEEDUSUALLY,WHENACCELERATIONISSMOOTH,THEDETACHMENTOFALOADFROMTHEBASEOCCURSIN3545SAFTERSWITCHINGONANELECTRICDRIVESIGNIFICANTOSCILLATIONSOFTHEMETALWORKARENOTOBSERVEDINTHISCASE,ANDSTRESSESSMOOTHLYREACHMAXIMUMVALUESWHENAHIGHACCELERATIONWITHTHEGREATESTPOSSIBLECLEARANCEINTHEJOINTBETWEENSPREADERANDGRABTAKESPLACE,THETENSIONOFTHEROPESHAPPENS1SAFTERSWITCHINGTHEELECTRICDRIVEON,THECLEARANCEINTHEJOINTTAKINGUPTHEREVOLUTIONSOFTHEELECTRICMOTORSREACHTHENOMINALVALUEINOR07STHEDETACHMENTOFALOADFROMTHEBASE,FROMTHEMOMENTOFSWITCHINGELECTRICMOTORSONTOTHEMOMENTOFFULLPULLINTHEROPESTAKES335S,THETENSIONSINROPESINCREASINGSMOOTHLYTOMAXIMUMTHESTRESSESINTHEMETALWORKOFTHEBRIDGEANDSUPPORTSGROWUPTOMAXIMUMVALUESIN12SANDOSCILLATEABOUTANAVERAGEWITHIN35WHENARIGIDLOADISLIFTED,THEACCELERATEDVELOCITYOFLOADINGINTHEROPEHANGERANDMETALWORKISPRACTICALLYTHESAMEASINCASEOFFASTHOISTINGOFALOGPACKTHEMETALWORKOSCILLATIONSARECHARACTERIZEDBYTWOHARMONICPROCESSESWITHPERIODS06AND2S,WHICHHAVEBEENOBTAINEDFROMSPECTRALANALYSISTHEWORSTCASEOFLOADINGENSUESFROMSUMMATIONOFLOADINGAMPLITUDESSOTHATTHEMAXIMUMEXCESSOFDYNAMICLOADINGABOVESTATICCANBE1314BRAKINGALOAD,WHENITISLOWERED,INDUCESSIGNIFICANTOSCILLATIONOFSTRESSINTHEMETALWORK,WHICHCANBER7OFSTATICLOADINGMOVINGOVERRAILJOINTSOF3MMHEIGHTMISALIGNMENTINDUCESONLYINSIGNIFICANTSTRESSESINOPERATION,THEREAREPOSSIBLECASESWHENLOADSORIGINATINGFROMVARIOUSTYPESOFLOADINGCOMBINETHEGREATESTLOADISTHECASEWHENTHEMAXIMUMLOADSFROMBRAKINGOFALOADWHENLOWERINGCOINCIDEWITHBRAKINGOFTHETROLLEYWITHPOORLYADJUSTEDBRAKES4FATIGUELOADINGANALYSISSTRAINMEASUREMENTATTESTPOINTS,DISPOSEDASSHOWNINFIGS4AND5,WASCARRIEDOUTDURINGTHEWORKOFTHECRANEANDAREPRESENTATIVENUMBEROFSTRESSOSCILLOGRAMSWASOBTAINEDSINCEACOMMONOPERATIONCYCLEDURATIONOFTHECRANEHASASUFFICIENTSCATTERWITHAVERAGEVALUE115MIN,TOREDUCETHESEOSCILLOGRAMSUNIFORMLYAFILTRATIONWASIMPLEMENTEDTOTHESESIGNALS,ANDALLREPEATEDVALUES,IEWHILETHECONSTRUCTIONWASNOTSUBJECTEDTODYNAMICLOADINGANDONLYSTATICLOADINGOCCURRED,WEREREJECTEDTHREECHARACTERISTICSTRESSOSCILLOGRAMSGAUGE11ARESHOWNINFIG6WHERETHEINTERIORSEQUENCEOFLOADINGFORANOPERATIONCYCLEISVISIBLEATFIRST,STRESSESINCREASETOMAXIMUMVALUESWHENALOADISHOISTEDAFTERTHATALOADISTRANSFERREDTOTHENECESSARYLOCATIONANDSTRESSESOSCILLATEDUETOTHEIRREGULARCRANEMOVEMENTONRAILSANDOVERRAILJOINTSRESULTINGMOSTLYINSKEWLOADSTHELOWERINGOFTHELOADCAUSESTHEDECREASEOFLOADINGANDFORMSHALFOFABASICLOADINGCYCLE41ANALYSISOFLOADINGPROCESSAMPLITUDESTWOTERMSNOWSHOULDBESEPARATEDLOADINGCYCLEANDLOADINGBLOCKTHEFIRSTDENOTESONEDISTINCTOSCILLATIONOFSTRESSESCLOSEDLOOP,ANDTHESECONDISFORTHESETOFLOADINGCYCLESDURINGANOPERATIONCYCLETHERAINFLOWCYCLECOUNTINGMETHODGIVENINREF2WASTAKENADVANTAGEOFTOCARRYOUTTHEFATIGUEHYSTERETICLOOPANALYSISFORTHETHREEWEAKESTELEMENTS1ANGLEOFTHEBOTTOMCHORDGAUGE11,2IBEAMOFTHETOPCHORDGAUGE17,3ANGLEOFTHESUPPORTGAUGE8STATISTICALEVALUATIONOFSAMPLECYCLEAMPLITUDESBYMEANSOFTHEWAYBILLDISTRIBUTIONFORTHESEELEMENTSHASGIVENESTIMATEDPARAMETERSFISTEDINTABLE4ITSHOULDBENOTEDTHATTHEHISTOGRAMSOFCYCLEAMPLITUDEWITHNONZEROAVERAGESWEREREDUCEDAFTERWARDSTOEQUIVALENTHISTOGRAMSWITHZEROAVERAGES42NUMBERSOFLOADINGCYCLESDURINGTHERAINFLOWCYCLECOUNTINGPROCEDURE,THECALCULATIONOFNUMBEROFLOADINGCYCLESFORTHELOADINGBLOCKWASALSOCARRIEDOUTWHILEPROCESSINGTHEOSCILLOGRAMSOFONETYPE,ASAMPLENUMBEROFLOADINGCYCLESFORONEBLOCKISOBTAINEDCONSISTINGOFINTEGERSWITHMINIMUMANDMAXIMUMOBSERVEDVALUES24AND46THERANDOMNUMBEROFLOADINGCYCLESVIBECANBEDESCRIBEDBYTHEPOISSONDISTRIBUTIONWITHPARAMETER34AVERAGENUMBERSOFLOADINGBLOCKSVIAMONTHSWEREOBTAINEDEARLIER,SOITISPOSSIBLETOFINDTHEAPPROPRIATECHARACTERISTICSNOTONLYFORLOADINGBLOCKSPERMONTH,BUTALSOFORTHETOTALNUMBEROFLOADINGCYCLESPERMONTHORYEARIFTHECENTRALLIMITTHEOREMISTAKENADVANTAGEOFFIRSTLY,ITISKNOWNFROMPROBABILITYTHEORYTHATTHEADDITIONOFKINDEPENDENTPOISSONVARIABLESGIVESALSOARANDOMVARIABLEWITHTHEPOISSONDISTRIBUTIONWITHPARAMETERK,ONTHEOTHERHAND,THEPOISSONDISTRIBUTIONCANBEWELLAPPROXIMATEDBYTHENORMALDISTRIBUTIONWITHAVERAGE,ANDVARIATION,SECONDLY,THECENTRALLIMITTHEOREM,ROUGHLYSPEAKING,STATESTHATTHEDISTRIBUTIONOFALARGENUMBEROFTERMS,INDEPENDENTOFTHEINITIALDISTRIBUTIONASYMPTOTICALLYTENDSTONORMALIFTHEINITIALDISTRIBUTIONOFEACHINDEPENDENTTERMHASANORMALDISTRIBUTION,THENTHEAVERAGEANDSTANDARDDEVIATIONOFTHETOTALNUMBEROFLOADINGCYCLESFORONEYEARAREEQUALTO423,096AND650ACCORDINGLYTHEVALUESOFKARETAKENASCONSTANTAVERAGESFROMTABLE35STRESSCONCENTRATIONFACTORSANDELEMENTENDURANCETHEELEMENTSOFTHECRANEAREJOINTEDBYSEMIAUTOMATICGASWELDINGWITHOUTPRELIMINARYEDGEPREPARATIONANDCONSEQUENTMACHININGFORTHEINSPECTEDELEMENTS1AND3HAVINGCIRCUMFERENTIALANDEDGEWELDSOFANGLESWITHGUSSETPLATES,THEEFFECTIVESTRESSCONCENTRATIONFACTORFORFATIGUEISGIVENBYCALCULATIONMETHODS3,KF2R29,COINCIDINGWITHESTIMATESGIVENINTHECURRENTRUSSIANNORMFORFATIGUEOFWELDEDELEMENTS4,KF29THEELEMENTSOFTHECRANEMETALWORKAREMADEOFALLOYEDSTEEL09G2SHAVINGANENDURANCELIMITOF120MPAANDAYIELDSTRENGTHOF350MPATHENTHEAVERAGEVALUESOFTHEENDURANCELIMITSOFTHEINSPECTEDELEMENTS1AND3AREES一L41MPATHEVARIATIONCOEFFICIENTISTAKENAS01,ANDTHECORRESPONDINGSTANDARDDEVIATIONIS6S、一41MPATHEINSPECTEDELEMENT2ISANIBEAMPIERCEDBYHOLESFORATTACHINGRAILSTOTHETOPFLANGETHERATHERLARGELOCALSTRESSESCAUSEDBYLOCALBENDINGALSOPROMOTEFATIGUEDAMAGEACCUMULATIONACCORDINGTOTABLESFROM4,THEEFFECTIVESTRESSCONCENTRATIONFACTORISACCEPTEDASKF18,WHICHGIVESANAVERAGEVALUEOFTHEENDURANCELIMITASES一LH7MAPUSINGTHESAMEVARIATIONCOIFFINGDENTTHESTANDARIDDEMITIONIS67MPA1SANAVERAGESNCURVE,RECOMMENDEDIN4,HASTHEFORMWITHTHEINFLEXIONPOINTNO5106ANDTHESLOPEM45FORELEMENTS1AND3ANDM55FORELEMENT2THEPOSSIBLEVALUESOFTHEELEMENTENDURANCELIMITSPRESENTEDABOVEOVERLAPTHERANGESOFLOADAMPLITUDEWITHNONZEROPROBABILITY,WHICHMEANSTHATTHESEELEMENTSARESUBJECTEDTOFATIGUEDAMAGEACCUMULATIONTHENITISPOSSIBLETOCONCLUDETHATFATIGUECALCULATIONSFORTHEELEMENTSARENECESSARYASWELLASFATIGUEFIFEPREDICTION6LIFEPREDICTIONTHESTUDYHASTHATSOMEELEMENTSOFTHEMETALWORKARESUBJECTTOFATIGUEDAMAGEACCUMULATIONTOPREDICTFIVESWESHALLTAKEADVANTAGEOFINTRINSICFATIGUECURVES,WHICHAREDETAILEDIN5AND6FOLLOWINGTHETHEORYOFINTRINSICFATIGUECURVES,WEGETLOGNORMALLIFEDISTRIBUTIONDENSITIESFORTHEINSPECTEDELEMENTSTHEFIFEAVERAGESANDSTANDARDDEVIATIONSAREFISTEDINTABLE5THELOGNORMALFIFEDISTRIBUTIONDENSITIESARESHOWNINFIG7ITISSEENFROMTHISTABLETHATTHELEASTFIFEISFORELEMENT3RECOLLECTINGTHATANAVERAGENUMBEROFLOADBLOCKSFORAYEARISEQUALTO12,719,ITISCLEARTHATTHEAVERAGESERVICEFIFEOFTHECRANEBEFOREFATIGUECRACKSAPPEARINTHEWELDEDELEMENTSISSUFFICIENTTHEFIFEIS85YEARSFORELEMENT1,115YEARSFORELEMENT2,ANDHYEARSFORELEMENT3HOWEVER,THEPROBABILITYOFFAILUREOFTHESEELEMENTSWITHINTHREEFOURYEARSISNOTSMALLANDISINTHERANGE009022THESEPROBABILITIESCANNOTBENEGLECTED,ANDSERVICESOFDESIGNANDMAINTENANCESHOULDMAKEEFFORTSTOEXTENDTHEFIFEOFTHEMETALWORKWITHOUTPERMITTINGCRACKINITIATIONANDPROPAGATION7CONCLUSIONSTHEANALYSISOFTHECRANELOADINGHASSHOWNTHATSOMEELEMENTSOFTHEMETALWORKARESUBJECTEDTOLARGEDYNAMICLOADS,WHICHCAUSESFATIGUEDAMAGEACCUMULATIONFOLLOWEDBYFATIGUEFAILURESTHEPROCEDUREOFFATIGUEHFEPREDICTIONPROPOSEDINTHISPAPERINVOLVESTOURPARTS1ANALYSISOFTHEOPERATIONINPRACTICEANDDETERMINATIONOFTHELOADINGBLOCKSFORSOMEPERIOD2RAINFLOWCYCLECOUNTINGTECHNIQUESFORTHECALCULATIONOFLOADINGCYCLESFORAPERIODOFSTANDARDOPERATION3SELECTIONOFAPPROPRIATEFATIGUEDATAFORMATERIAL4FATIGUEFIFECALCULATIONSUSINGTHEINTRINSICFATIGUECURVESAPPROACHTHERESULTSOFTHISINVESTIGATIONHAVEBEENCONFIRMEDBYTHECASESOBSERVEDINPRACTICE,ANDTHEMANUFACTURERSHAVETAKENADECISIONABOUTSTRENGTHENINGTHEFIXEDELEMENTSTOEXTENDTHEIRFATIGUELIVESREFERENCES1FELLERWANINTRODUCTIONTOPROBABILISTICTHEORYANDITSAPPLICATIONS,VOL23RDEDWILEY,19702RYCHLIKIINTERNATIONALJOURNALOFFATIGUE198791193PISKUNOVVIFINITEELEMENTSANALYSISOFCRANESMETALWORKMOSCOWMASHINOSTROYENIE,1991INRUSSIAN4MURD5069490RELIABILITYENGINEERINGPROBABILISTICMETHODSOFCALCULATIONSFORFATIGUEOFWELDEDMETALWORKSMOSCOWIOSSTANDARD,1990INRUSSIAN5KOPNOVVAFATIGUEANDFRACTUREOFENGINEERINGMATERIALSANDSTRUCTURES19931610416KOPNOVVATHEORETICALANDAPPLIEDFRACTUREMECHANICS199726169中文翻譯龍門式起重機金屬材料的疲勞強度預測VA科普諾夫摘要內(nèi)在的疲勞曲線應用到龍門式起重機金屬材料的疲勞壽命預測問題。起重機，用于在森林工業(yè)中，在伐木林場對各種不同的工作條件進行研究，并且做出相應的應變測量。對載重的循環(huán)周期進行計算，下雨循環(huán)計數(shù)技術得到了使用。在一年內(nèi)這些起重機運作的樣本被觀察為了得到運作周期的平均數(shù)。疲勞失效分析表明，一些元件的故障是自然的系統(tǒng)因素，并且不能被一些隨意的原因所解釋。1999年ELSEVIER公司科學有限公司。保留所有權利。關鍵詞起重機疲勞評估應變測量1緒論頻繁觀測龍門式起重機LT62B在運作時金屬元件疲勞失效。引起疲勞裂紋的故障沿著起重機的橋梁焊接接頭進行傳播，并且能夠支撐三到四年。這種起重機在森林工業(yè)的伐木林場被廣泛使用，用來轉移完整長度的原木和鋸木到鐵路的火車上，有一次裝載30噸貨物的能力。這種類型的起重機大約1000臺以上工作在俄羅斯森林工業(yè)的企業(yè)中。限制起重機壽命的問題即最弱的要素被正式找到之后，預測其疲勞強度，并給制造商建議，以提高起重機的壽命。2起重機運行分析為了分析，在葉卡特琳堡地區(qū)的林場碼頭選中了一臺被安裝在葉卡特琳堡地區(qū)的林場碼頭的龍門式起重機LT62B，這臺起重機能夠供應兩個伐木廠建立存儲倉庫，并且能轉運木頭到鐵路的火車上，這條鐵路通過存儲倉庫。這些設備的安裝就是為了這個轉貨地點在起重機的跨度范圍之內(nèi)。一個起重機示意圖顯示在圖1中。13506307/99/元，看到前面的問題。1999年ELSEVIER公司科學有限公司保留所有權利。PHS1350630798000417VAKOPNOV|機械故障分析6（1999）131141圖1起重機簡圖檢查起重機的工作之后，一系列的假設可能會作出如果每月從森林移動的原木超過加工率，即是有一個原木存儲的倉庫，這個起重機期待的工作，也只是在原木加工的實際堆數(shù)在所供給原木數(shù)量的中心線以下；當處理超過原木從森林運出的速度時，起重機的工作需要在的大量的木材之上進行操作，相當于在大量的木材上這個鋸木廠賺取的很少；原木不同的倉庫大量的木材的高度被認為是最高的倉庫的變化，取替了一側對面的鋸軋機裝載進程中總量是平均為K14倍大于移動總量由于額外的轉移。21搬運強度據(jù)了解，每年的搬運強度是不規(guī)律的，不能被視為一個平穩(wěn)過程。非平穩(wěn)流動的道路列車的性質(zhì)在23家企業(yè)中已經(jīng)研究5年的時間，結果已經(jīng)表明在年復一年中，對于每個企業(yè)來說，每個月的搬運強度都是不同的。這是解釋復雜的各種系統(tǒng)和隨機效應，對搬運施加的影響天氣條件，道路條件和貨車車隊等，所有木材被運送到存儲倉庫的木材，在一年內(nèi)應該被處理。因此，在春季和秋季搬運木頭的可能性越來越小，冬天搬運的可能性越來越大，然而在冬天搬運強度強于預想的，在夏天的情況下，更多足夠長的木材就地被處理的比運出去的要多的多。VAKOPNOV|機械故障分析6（1999）131141表1搬運強度（）表2轉移儲存量通過一年的觀察，從118各搬運值的觀察所了解到的數(shù)據(jù)進行分析，并且有可能評價相關的搬運強度（噸）參考年度的裝載量的百分比。該搬運的數(shù)據(jù)被記錄在起重機預期值表1中，它可以被應用到估計疲勞壽命，尤其是為檢查起重機應變測量（見稍后）。將有可能為每個起重機，每一個月所負荷的載重量，建立這些數(shù)據(jù)，無需特別困難的統(tǒng)計調(diào)查。此外，為了解決這個問題的壽命預測的知識是未來的荷載要求，在類似的操作條件下，我們采取起重機預期值。每月搬運價值的分布Q（T），被相對強度Q（T）表示為其中Q是每年的裝載量的記錄存儲，是設計的最大存儲原木值Q以百分比計算，其中為考察起重機等于400萬立方米每年，和容積載重搬運為10的起重機，得到的數(shù)據(jù)列在表2中，總量56000立方米每年，用K表示。22裝載木塊的數(shù)量這個運行裝置，如夾緊，吊裝，轉移，降低，和釋放負載可被視為起重機的一個運行周期（加載塊）。參照這個調(diào)查結果，以操作時間為一個周期，作為范本，由正常變量與平均值115分相等等，標準差為15分鐘。不幸的是，這個特點不能簡單地用于定義運作周期的數(shù)目，任何工作期間的載重加工是非常不規(guī)則。使用運行時間的起重機和評價周期時間，與實際增加一個數(shù)量的周期比，很容易得出比較大的誤差，因此，最好是作為如下。測量一個單位的載荷，可以作為范本，由一個隨機變量代入分布函數(shù)得出，并且比實際一包貨物少然后，明知總量的加工負荷為1個月或一年可能確定分布參數(shù)的數(shù)目，運作周期為這些時期要利用這個方法的更新理論VAKOPNOV|機械故障分析6（1999）131141圖2隨機重建過程中的負荷根據(jù)這些方法，隨機重建過程中所顯示的圖。二是考慮到，（隨機變量）負荷，形成了一個流動的數(shù)據(jù)鏈在重建的理論中，隨機變量，有一個分布函數(shù)F（T）的，可以被理解為在失敗的連接或N者要求收據(jù)時的恢復時刻。過程的載荷值，作為下一次的動作的通過值，被看作是重建的時刻。設。函數(shù)F（T）反復被定義，NNFTPT假設V（T）是在運作周期內(nèi)轉移貨物的數(shù)量。實踐中，總轉移貨物的總噸數(shù)，基本上是大于機組負荷，由于利用漸近性質(zhì)的重建過程所以式有益的。根據(jù)下面適當?shù)南拗浦亟ǘɡ?，需要轉移大量噸數(shù)。已正態(tài)分布漸近與均值和方差，確定抽樣數(shù)