有限元基础Project2Reportypesetted.docx
- 文档编号:11278834
- 上传时间:2023-02-26
- 格式:DOCX
- 页数:13
- 大小:692.15KB
有限元基础Project2Reportypesetted.docx
《有限元基础Project2Reportypesetted.docx》由会员分享,可在线阅读,更多相关《有限元基础Project2Reportypesetted.docx(13页珍藏版)》请在冰豆网上搜索。
有限元基础Project2Reportypesetted
UseABAQUStoImprovetheDesignofaConnecting-linkPortion.
Chang-HongLinghu
FiniteElementsMethods:
Mid-TermProject2
Summer2016
Date:
2016-06-7
ABSTRACT
Thestressconcentrationfactor,thevonMisesstressanddisplacementdistributionofaconnecting-linkportionareanalyzedusingfiniteelementsoftwareABAQUS.Symmetryisappliedtosimplifytheproblemandplanestressmodelisused.Anewdesigntoreducethestressconcentrationfactoratleast20%isdeveloped.Resultsshowsthatwhenthediameterofthecentralholeisnotinfinitesimalcomparedwiththewidthoftheconnecting-linkportion,thestressconcentrationfactorislessthan3(theanalyticalresultwhenthecentralholeisaninfinitesimalone).Themostdangerouspositionisthelowerboundofthechamfer,wherethestressconcentrationfactoris2.942.Bysubstitutingthechamferwithasmoothtransition,thestressconcentrationaroundthechamferiseliminatedandthestressconcentrationfactorofthewholestructureisreducedby34.01765%.
TABLEOFCONTENTS
ABSTRACT......................................................................................................................................................1
TABLEOFCONTENTS.............................................................................................................................….2
LISTOFFIGURES...........................................................................................................................................2
LISTOFTABLES............................................................................................................................................2
APurpose.........................................................................................................................................................3
BIntroduction:
theconnecting-linkportionsubjectedtouniaxialstaticloadandthenewdesign...................3
CFiniteElementModelDevelopment……………..........................................................................................3
C.1Meshscheme…………………...........................................................................................................3
C2GridIndependence..................................................…….....................................................................3
DResultsandDiscussion.................................................................................................................................3
D.1thevonMisesstressanddisplacementdistribution...........................................................................3
D.2stressconcentrationfactorandthenewdesign………………………..............................................4
EConclusionandRecommendations.................................................................................................................4References.......................................................................................................................................................…5
FAppendices………….....................................................................................................................................6
Figures……….................................................................................................................................................6
TABLES………..............................................................................................................................................11
LISTOFFIGURES
Fig.1Thediagramoftheconnecting-linkportion………………..................................................................6
Fig.2TheplanestressmodeldevelopedinABAQUSCAE..........................................................................6
Fig.3ThepreliminaryanalysisusingCSP6elementandcoarsemesh...........................................................7
Fig.4Adiagramofthemeshscheme.............................................................................................................7
Fig.5ThevonMisesstresscontour..................................................................................................................8
Fig.6ThevonMissesstresscontouraroundthecentralhole..........................................................................8
Fig.7Thedisplacementdistributioncontour..................................................................................................9
Fig.8dimensionsofthenewdesigntoreducethestressconcentrationfactor..............................................10
Fig.9theS11distributionofthenewdesign.................................................................................................10
LISTOFTABLES
Table1.Dimensionsoftheconnecting-portion…………………….................................................................11
Table2.Theresultofthemeshindependencetest............................................................................................11
A.PurposeandScope.
Thepurposeofthisreportistofindthestressconcentrationfactor(definedas
)andprobethevonMisesstressandthedisplacementdistributionofaconnecting-linkportion(showninfig.1)subjectedtouniaxialstaticload
byfiniteelementsoftwareABAQUS,andfinallygiveanewdesigntoreducethestressconcentrationfactoratleast20%.
BIntroduction:
theconnecting-linkportionsubjectedtouniaxialstaticload
Thegeometryoftheconnecting-linkportionisshowninfig.1andthedimensionsaregiveninTable1.ThematerialissteelwithYoung’smodulus200GPaandPoisson’sratio0.3.Theconnecting-linkportionissubjectedtheuniaxialstaticload
.FromMechanicsofMaterialsweknowthatstressconcentrationwilloccurifthecrosssectionareaofastructurechangedramaticallyoradefect(suchasaholeofacrack)exists.Thestressconcentrationareatendstobedangerousofthestructureduetoitsheavilystressedcondition.Thusadesignerisobligatedtotakeeveryproceduretoreducethestressconcentrationfactorofastructure,andthechamferisjustonemethodtoreducethestressconcentration.
CFiniteElementModelDevelopment
Weusetheplanestressassumptionsincethethicknessissmall.Duetothesymmetryoftheplatewewillmodeljustonefourthoftheplate,seeFig.2.Thesymmetrypropertyofthestructurecansimplifyourmodelandreducethecalculationcost,forbigproblems,thisisveryuseful.
C.1Meshscheme
Apreliminaryanalysis(showninfig.3)showsthatthestress-concentratedpositionsaretheupperboundofthecentralholeandthelowerpartofthechamfer.Thusinthefollowinganalysesthesetwopartsarepartitionedandthemeshthereisdensified(asshowninfig.4).Togetbetterresultsaboutthestressconcentration,higherorderelementCSP8isused.
C2GridIndependence
Toshowthatourresultisconvergentandindependentofthemesh,agridindependencetestisperformed.Theresult(aslistedintable2)showswhentheelementnumberinpartagrowsfrom320to373,thestressconcentrationfactoraroundthecentralholegrowsfrom2.29484to2.29830,onlyachangeof0.150773%;whilethestressconcentrationfactoraroundthechamferremains2.942whentheelementnumberinpartbgrowsfrom615to770.Thisshowsthatourresultisconvergent.
D.ResultsandDiscussion
WeshalldiscussthevonMisesstressanddisplacementdistributionofaconnecting-linkportion,followedbythestressconcentrationfactoroftheorigindesign.Andfinallygivethenewdesigntoreducethestressconcentrationfactoratleast20%.
D.1thevonMisesstressanddisplacementdistribution
thevonMisesstresscontourisshowninfig.5.Fromfig.5wecanseethatthemaximumvonMisesstressoccursatthelowerpartofthechamferandtheminimumneartheupperfreecornerofthewholestructure.ThemaximumvonMisesstresstakesthevalueof16.06MPaandtheminimum0.04469MPa.
Asanadjacentpartofthisreport,thevonMisesstresscontouraroundthecentralholeisgiveninfig.6,onecanseethestressaroundthecentralholegetitsgreatestvalueattheupperboundofthehole,perpendiculartotheloadingdirection,whichagreeswiththeanalyticalresultinElasticsverywell.
Thedisplacementdistributionisshowninfig.7.Becausethestructureissymmetric,theaxialdisplacementU1iszeroontheleftsymmetryaxis,andgrowsformlefttoright.Thelateraldisplacement(causedbyPoisson’seffect)distributionisquitecomplex.Thefreecornercandeformfreelywhiletheaxialsymmetryaxisisconfined,asaresult,thefreecornerexpandslaterallywhiletheupcornerontheaxialsymmetryaxiscontracts.Themaximumandminimumdisplacementsarelabeledinthefig7.
D.2stressconcentrationfactorandthenewdesign.
Thestressconcentrationfactoroftheoriginaldesignis2.942,whichoccursatthelowerpartofthechamfer,thisismainlycausedbythedramaticallychangeofthecrosssectionareaalongtheloadingdirection.Bysubstitutethesmallchamfer(r=2.5mm)withtwocirculararcs(assowninfig.8),thecrosssectionareachangessmoothlyalongtheloadingaxis,thestressconcentrationaroundthechamferiseliminated.Thestressconcentrationaroundthecentralholestillexistsbutbecomessmaller(asshowninfig.9).Thestressconcentrationfactorofthewholestructurebecomes1.9412,areductionof34.01765%comparedwiththeoriginaldesign(intermsofthestressconcentrationfactorofthewholestructure).
Oneinterestingphenomenonisthatthestressconcentrationfactoraroundthecentralholeis2.2983ratherthan3(theanalyticalresultwhenthecentralholeisaninfinitesimalone).Theres
- 配套讲稿:
如PPT文件的首页显示word图标,表示该PPT已包含配套word讲稿。双击word图标可打开word文档。
- 特殊限制:
部分文档作品中含有的国旗、国徽等图片,仅作为作品整体效果示例展示,禁止商用。设计者仅对作品中独创性部分享有著作权。
- 关 键 词:
- 有限元 基础 Project2Reportypesetted
![提示](https://static.bdocx.com/images/bang_tan.gif)