简介:Thephenomenonofearingisinvestigatedinthepresentstudybasedonthetheoryofcrystalplasticitywiththedynamicexplicitfiniteelementprogramdeveloped.FirstlytextureanalysisiscarriedoutofrolledaluminiumalloyA15052bymeansofX-raytechnique.Thenfromthetexturecoefficientsananalyticalexpressionfortheorientationdistributionfunction(ODF)isderivedmakinguseofthecomputeralgebraiclanguageMathematica4.0,whichmakesiteasiertodiscretizetheODFintoaseriesofEuleriananglesrepresentingthedistributionoflatticesandfurtherthepreferredorientation(texture)ofcrystalsoftheoriginalsheets.Forthepolycrystalmodel,thematerialisdescribedusingcrystalplasticitywhereeachmaterialpointinthesheetisassumedtobeapolycrystallineaggregateofaverylargenumberofface-centeredcubic(FCC)grainswitheachgrainmodelledasanFCCcrystalwith12distinctslipsystems.ThemodifiedTaylortheoryofcrystalplasticityisusedandonlytheinitialtextureistakenintoconsiderationduringlargeplasticdeformation.Numericalsimulationofearinghasbeenperformedforanaluminiumsheetwithtextureandonewithcrystalsexhibitingrandomdistributiontodemonstratetheeffectoftextureofmaterialsontheirplasticanisotropyandformability.
简介:Anapproachbasedoncontinuumdamagemechanicstofatiguelifepredictionforstructuresisproposed.Anewfatiguedamageevolutionequationisdeveloped,inwhichtheparametersareobtainedinasimplewaywithreferencetotheexperimentalresultsoffatiguetestsonstandardspecimens.WiththeutilizationofAPDLlanguageontheANSYSplatform,afiniteelementimplementationispresentedtoperformcouplingoperationondamageevolutionofmaterialandstressredistribution.ThefatiguelivesofsomenotchedspecimensandaPitch-change-linkarepredictedbyusingtheaboveapproach.Thecalculatedresultsarevalidatedwithexperimentaldata.
简介:Inthispaper,thep-versionofthefiniteelementmethodoflines(FEMOL)fortheanalysisoftheMindlin-Reissnerplatebendingproblemsispresentedandaclassofp-FEMOLelementswithpolynomialdegreesashighasnineisdeveloped.Numericalexamplesgiveninthispapershowtremendousperformanceofthepresentmethod;namely,rapidconvergencerate,highaccuracyforbothdisplacementsandstressresultants,removalofshear-lockingtrouble,capabilityofdealingwithdifficultproblemssuchastheboundarylayerbehaviornearafreeedgeandstressconcentrationaroundahole.
简介:这篇论文介绍各向异性的损坏理论的应用程序给形成A12024T3铝合金表的限制图的学习。在限制铝板结构的紧张的预言,一个有限元素房间模型被构造了。房间模型由二个阶段,铝合金矩阵和金属间化合的簇组成。铝合金矩阵的材料行为与充分联合的elasto塑料的损坏被描述组成的方程。金属间化合的簇被假定有弹性、易碎。由改变拉长的比率,在二轴的拉长下面的表的限制紧张被使用建议的necking标准预言了。预言在对试验性的调查结果的好同意。而且,有限元素房间模型能为理解铝合金的显微镜的损坏机制提供信息。如果材料损坏的效果在形成学习的表金属被忽略,限制紧张的在评价上可以结果。
简介:这研究的目的是评估本地人爬象粗糙的颗粒的热那样的各种各样的微观结构的损坏影响了地区(CGHAZ),精细的热影响了地区(FGHAZ),intercritical热影响了作为类型IV区域知道的地区(ICHAZ),焊接金属,并且由小穿孔机(SP)基于P92(9Cr-2W)钢焊接的金属爬在600掳C的测试。另外,焊接分开决定最弱的本地人,微观结构在上的效果爬在P92钢的焊接的破裂行为被学习。从试验性的结果,FGHAZ和类型IV区域结果是P92焊接的很弱的本地部分。特别,TYPEIV区域显示出最大的排水量率并且与许多过了最短的破裂生活爬洞广泛地在大多数这个区域传播了。
简介:Toconsidertheanisotropicdamageinfatigue,animprovedboom-panelmodelispresentedtosimulatearepresentativevolumeelement(RVE)intheframeworkofcontinuumdamagemechanics.TheanisotropicdamagestateoftheRVEisdescribedbythecontinuityextentsofboomsandpanels,whosedamageevolutionsareassumedtobeisotropic.Thenumericalimplementationisproposedonthebasisofdamagemechanicsandthefiniteelementmethod.Finally,theapproachisappliedtothefatiguelifepredictionof2A12-T4aluminiumalloyspecimenundercyclicloadingoftension-torsion.Theresultsindicateagoodagreementwiththeexperimentaldata.
简介:与浸透的土壤存款的由一条半球的冲积山谷的三维的散布和飞机P波浪的衍射的一个分析解决方案被采用Fourier-Bessel系列扩大技术开发。不同于以前的研究,浸透的土壤存款与单相的有弹性的理论在被模仿,在这篇论文,他们为浸透的多孔的媒介,和一半与Biot的动态理论被模仿空间作为asingle阶段被假定橡皮媒介。更少的频率,发生角度ofP波浪和土壤的孔在半球的冲积山谷的表面排水量放大上扔的尺寸的效果被调查。数字结果证明一条浸透的半球的冲积山谷的存在在表面排水量放大上有许多影响。当与发生ofP波浪评估一条半球的冲积山谷的排水量回答时,与Biot的动态理论模仿土壤存款是更合理的。