ANSYS-疲劳-应力寿与命

Fatigue Stress Life WorkshopA12 1 August26 2005Inventory 002266WSA12 1 2 Goals Goal InthisworkshopourgoalistoperformaStress Lifeanalysisoftheconnectingrodmodel ConRod x t shownhere Specifically wewillanalyzetwoloadenvironments 1 ConstantAmplitudeLoadof4500N FullyReversedand2 RandomLoadof4500N August26 2005Inventory 002266WSA12 1 3 StartPage FromthelauncherstartSimulation Choose Geometry FromFile andbrowsetothefile ConRod x t WhenDSstarts closetheTemplatemenubyclickingthe X inthecornerofthewindow August26 2005Inventory 002266WSA12 1 4 Preprocessing Changetheworkingunitsystemtometric m kg Pa Units Metric m kg Pa C s Verifythematerialissetto StructuralSteel Highlightthe Part1 inthegeometrybranch Ifnot clickinthe Material fieldand browse 1 2 3 August26 2005Inventory 002266WSA12 1 5 Preprocessing Selectthe StructuralSteel materialandthenclick OK 4 August26 2005Inventory 002266WSA12 1 6 Preprocessing Applythefollowingboundaryconditions seenextpage August26 2005Inventory 002266WSA12 1 7 Preprocessing HighlighttheEnvironmentbranch Highlighttheconnectingrodsurfaceshown Insertaforceload RMB Insert Force Fromthedetailwindowchangeto Components and Z 4500N 6 5 7 8 August26 2005Inventory 002266WSA12 1 8 Preprocessing HighlighttheEnvironmentbranch Highlighttheconnectingrodsurfacesshown Insertacylindricalsupport RMB Insert CylindricalSupport FromtheDetailsof CylindricalSupport window SetRadial Fixed Axial Free Tangential Free 10 9 11 12 August26 2005Inventory 002266WSA12 1 9 Preprocessing HighlighttheEnvironmentbranch Highlighttheconnectingrodsurfaceshown Insertafixedsupport RMB Insert FixedSupport 14 13 15 August26 2005Inventory 002266WSA12 1 10 AddresultstoSolution Highlightthesolutionbranch RMB Insert Stress Equivalent vonMises RMB Insert Deformation Total SolutionSetup 16 August26 2005Inventory 002266WSA12 1 11 Insertfatiguetool Highlightthesolutionbranch RMB Insert Fatigue FatigueTool SolutionSetup 20 19 August26 2005Inventory 002266WSA12 1 12 FromtheDetailsof FatigueTool window SpecifyaFatigueStrengthFactor Kf of 8 materialdatarepresentsapolishedspecimenandthein servicecomponentiscast Specifyfullyreversedloadingtocreatealternatingstresscycles Specifyastress lifefatigueanalysis Nomeanstresstheoryneedstobespecifiedsincenomeanstresswillexist fullyreversedloading SpecifythatVonMisesstresswillbeusedtocompareagainstfatiguematerialdata SolutionSetup August26 2005Inventory 002266WSA12 1 13 AddresultstotheFatigueTool Insert SafetyFactor RMB Insert Fatigue SafetyFactor FromtheDetailsof SafetyFactor window SettheDesignLifeto1e6cycles SolutionSetup 26 August26 2005Inventory 002266WSA12 1 14 AddresultstotheFatigueTool cont Insert FatigueSensitivity RMB Insert Fatigue FatigueSensitivityFromtheDetailsof FatigueSensitivity window Specifyaminimumbaseloadvariationof50 analternatingstressof2250N andamaximumbaseloadvariationof200 analternatingstressof9000N SolutionSetup 28 August26 2005Inventory 002266WSA12 1 15 AddresultstotheFatigueTool cont Insert BiaxialityIndication RMB Insert Fatigue BiaxialityIndicationSolve SolutionSetup 29 August26 2005Inventory 002266WSA12 1 16 ViewResultsHighlightandplotthe TotalDeformation result Results August26 2005Inventory 002266WSA12 1 17 Highlightandplotthe EquivalentStress result Results August26 2005Inventory 002266WSA12 1 18 Highlightandplotthe SafetyFactor resultforadesignlifeof1e6cycles Results August26 2005Inventory 002266WSA12 1 19 Highlightandplotthe FatigueSensitivity resultforaminimumbaseloadvariationof50 andamaximumbaseloadvariationof200 Results August26 2005Inventory 002266WSA12 1 20 Findthesensitivityofavailablelifewithrespecttoloadingforamaximumbaseloadvariationof400 Note mustresolvetoobtainthenewFatigueSensitivityresults Results August26 2005Inventory 002266WSA12 1 21 Highlightandplotthe BiaxialityIndication result Note thestressstatenearthecriticallocationisnotfarfromuniaxial 1 2 whichgivesanaddedmeasureofconfidencesincethematerialpropertiesareuniaxial Recall abiaxialityofzerocorrespondstouniaxialstress avalueof 1correspondstopureshear andavalueof1correspondstoapurebiaxialstate Results August26 2005Inventory 002266WSA12 1 22 Insertasecondfatiguetooltoanalyzearandomloadof4500N Assumethatwehavestraingaugeresultsthatwerecollectedexperimentallyfromthecomponentandthatweknowthatastraingaugereadingof200correspondstoanappliedloadof4500N Highlightthesolutionbranch RMB Insert Fatigue FatigueTool SolutionSetup 31 30 August26 2005Inventory 002266WSA12 1 23 FromtheDetailsof FatigueTool2 window SpecifyaFatigueStrengthFactor Kf of 8 materialdatarepresentsapolishedspecimenandthein servicecomponentiscast Specifyfatigueloadingascomingfromascalehistoryandselectscalehistoryfilecontainingstraingaugeresultsovertime browseandopenthe SAEBracketHistory dat file Definethescalefactortobe 005 wemustnormalizetheloadhistorysothattheFEMloadmatchesthescalefactorsintheloadhistoryfile SolutionSetup August26 2005Inventory 002266WSA12 1 24 FromtheDetailsof FatigueTool window cont SpecifyGoodmantheorytoaccountformean stresseffects SpecifythatasignedVonMisesstresswillbeusedtocompareagainstfatiguematerialdata usesignedsinceGoodmantheorytreatsnegativeandpositivemeanstressesdifferently Specifyabinsizeof32 RainflowandDamagematriceswillbeofdimension32x32 SolutionSetup August26 2005Inventory 002266WSA12 1 25 AddresultstotheFatigueTool2 Insert Life RMB Insert Fatigue LifeInsert SafetyFactor RMB Insert Fatigue SafetyFactorFromtheDetailsof SafetyFactor window SettheDesignLifeto1000cycles SolutionSetup 39 40 38 August26 2005Inventory 002266WSA12 1 26 AddresultstotheFatigueTool cont Insert FatigueSensitivity RMB Insert Fatigue FatigueSensitivityFromtheDetailsof FatigueSensitivity window Specifyaminimumbaseloadvariationof50 analternatingstressof2250N andamaximumbaseloadvariationof200 analternatingstressof9000N SolutionSetup 41 42 August26 2005Inventory 002266WSA12 1 27 AddresultstotheFatigueTool cont Insert BiaxialityIndication RMB Insert Fatigue BiaxialityIndicationInsert RainflowMatrix RMB Insert Fatigue RainflowMatrix SolutionSetup 43 44 August26 2005Inventory 002266WSA12 1 28 AddresultstotheFatigueTool cont Insert DamageMatrix RMB Insert Fatigue DamageMatrixFromtheDetailsof DamageMatrix window SettheDesignLifeto1000cycles Solve SolutionSetup 45 46 August26 2005Inventory 002266WSA12 1 29 ViewResultsHighlightandplotthe Life result Results August26 2005Inventory 002266WSA12 1 30 Highlightandplotthe SafetyFactor resultforadesignlifeof1000cycles Results Iftheloadinghistorycorrespondedtotheloadingexperiencedbythepartoveramonthstime thedamageandFSwillbeatadesignlifeof1000months Notethatalthoughalifeofonly77loadingblocksiscalculated theneededscalefactor sinceFS 1000 60 isonly 60toreachalifeof1000blocks Note the scalefactor isthescalefactorfortheloadingtomakeitmeetthelifeof1000months August26 2005Inventory 002266WS