简介：AmechanicalmodelisestablishedformodeⅡinterfacialcrackstaticgrowingalonganelastic-elasticpowerlawcreepingbimaterialinterface.Forfrictionalcontactofboundaryconditionsoncrackfaces,asymptoticsolutionsofthestressesandstrainsofneartip-crackaregot.Itwasshownthatinstablecreepgrowingphase,elasticdeformationandviscousdeformationareequallydominantinthenear-tipfield,thestressandstrainhavethesamesingularityandthereisnottheoscillatorysingularitythefield.Throughnumericalcalculation,itisshownthatthefrictionalcoefficientηnotablyinfluencethecrack-tipfield.

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简介：Asolutionispresentedforaclassoftwo-dimensionalelectroelasticbranchedcrackproblems.ExplicitGreen’sfunctionforaninterfacecracksubjecttoanedgedislocationisdevelopedusingtheextendedStrohformulationallowingthebranchedcrackproblemtobeexpressedintermsofcoupledsingularintegralequations.Theintegralequationsareobtainedbythemethodthatmodelsakinkasacontinuousdistributionofedgedislocations,andthedislocationdensityfunctionisdefinedonthelineofthebranchcrackonly.Competitionbetweencrackextensionalongtheinterfaceandkinkingintothesubstrateisinvestigatedusingtheintegralequationsandthemaximumenergyreleaseratecriterion.Numericalresultsarepresentedtoshowtheeffectofelectricfieldonthepathofcrackextension.

简介：AnewmechanicsmodelbasedonPeierlsconceptispresentedinthispaper,whichcanclearlycharacterizetheintrinsicfeaturesnearatipofaninterfacialcrack.Thestressanddisplacementfieldsarecalculatedundergeneralcombinedten-sileandshearloadings.Theneartipstressfieldsshowsomeoscillatorybehaviorsbutwithoutanysingularityandthecrackfacesopencompletelywithoutanyoverlappingwhenremotetensileloadingiscomparablewithremoteshearloading.Afracturecriterionforpredictinginterfacetoughnesshasbeenalsoproposed,whichtakesintoaccountfortheshieldingeffectsofemitteddislocations.Thetheoreticaltoughnesscurvegivesexcellentprediction,ascomparedwiththeexistingexperimentdata.

简介：本文从crack技术的初级阶段讲起逐表深入的介绍了一些crack知识或经验。在引出本文之前，我想说的是请大家能正视crack,据我所知的我认识的朋友和了解的cracker,大部分都不是为了金钱而破解的，很多人只是把它当作自己的兴趣而已，所谓的CCG、BCG等破解组织是软件盗版的基地更是无中生有，据我所知每个破解组织的规章其中就严格规定不得和盗版集团发生任何联系。国外也有破解组织而且水平比国内要高，为什么国外的软件能成功？这恐怕不仅仅是crack惹的祸！同时crack同样给我国的共享软件提供了巨大的能量。

简介：这篇论文在有限厚度的一次非同类的材料旅行认为一架反飞机是动人的快克。shear模量和长带的集体密度为平衡方程为有分析答案的功能的形式的一个班被考虑。这个问题借助于单个不可分的方程技术被解决。裂缝尖端附近的压力地被获得。结果被阴谋在裂缝尖端域上显示出材料非同质和快克移动速度的效果。裂缝分叉行为也被讨论。纸指出一个适当破裂标准的使用为在非同类的材料学习一个动人的裂缝的稳定性是必要的。预言不稳定的裂缝生长是否将被提高或延迟，强烈依赖于使用的破裂标准的类型。基于分析，看起来最大值“反飞机砍”在裂缝尖端附近的应力是为在非同类的材料的动人的裂缝的一个合适的失败标准。

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简介：Byusingthemethodofstressfunctions,theproblemofmode-ⅡGriffithcrackindecagonalquasicrystalswassolved.First,thecrackproblemoftwo-dimensionalquasicrystalswasdecomposedintoaplanestrainstateproblemsuperposedonanti-planestateproblemandsecondly,byintroducingstressfunctions,the18basicelasticityequationsoncouplingphonon-phasonfieldofdecagonalquasicrystalswerereducedtoasinglehigherorderpartialdifferentialequations.Thesolutionofthisequationundermixedboundaryconditionsofmode-ⅡGriffithcrackwasobtainedintermsofFouriertransformanddualintegralequationsmethods.Allcomponentsofstressesanddisplacementscanbeexpressedbyelementalfunctionsandthestressintensityfactorandthestrainenergyreleaserateweredetermined.

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简介：Experimentalrevelationofsuperbluntingalongplanestrainpredominantcracktipsegmentisre-portedhereformodifiedpolyproplene.Aselucidatedbyaheuristicmodelofprogressivecircumferentialcold-draw,theformationofsuperbluntingcracktipdependscriticallyontheratiobetweenthecold-drawprop-agationspeedandtheloadingspeed,andcontributessignificantlytothematerialtoughening,especiallyfortheimprovementinimpacttoughness.Detailednumericalcalculationsareconductedbasedonahyperelastic-viscoplasticandanisotropicdamageconstitutivemodelatfinitedeformation.Thesimulatedresultsrecapitulatetheessentialfeaturesofcracktipsuperblunting.

简介：Thepresentstudydevelopsthefracturetheoryforatwo-dimensionaloctagonalquasicrystals.TheexactanalyticsolutionofaModeⅡGriffithcrackinthematerialwasobtainedbyusingtheFouriertransformanddualintegralequationstheory,thenthedisplacementandstressfields,stressintensityfactorandstrainenergyreleaserateweredetermined,thephysicalsenseoftheresultsrelativetophasonandthedifferencebetweenmechanicalbehaviorsofthecrackproblemincrystalandquasicrystalwerefiguredout.Theseprovideimportantinformationforstudyingthedeformationandfractureofthenewsolidphase.

简介：Thefiniteelementformulationforanalyzingstaticdamagenearaconductingcrackinathinpiezoelectricplateisestablishedfromthevirtualworkprincipleofpiezoelectricity.Thedamagefieldsundervariousmechanicalandelectricalloadsarecalculatedcarefullybyusinganeffectiveiterativeprocedure.Thenumericalresultsshowthatallthedamagefieldsaroundacracktiparefan-shapedandtheelectricfieldappliedhasgreatinfluenceonthemechanicaldamage,whichisrelatedtothepiezoelectricproperties.

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简介：Inthispaper,aslowbendingspeedvarestrainttestmethodwithcon-tinuouslyadjustabledeformationratefortestinghotcrackingsensitivityisde-velopedanditsworkingprincipleisdescribed.Fromgreatamountsoftests,itisknownthatstrainrateaffectsthesensitivityofsolidificationcrackbecauseofitsinflunceonmaterialductilityinBTRdirectly.Thesmallerthestrainrate,thebettertheductilityandthelowerthesolidificationcracksensitivity.Theex-tentofthiseffectvarieswithdifferentmaterials,forLF-6aluminumalloy,itisgreat,butfor16Mn,19Mn5and20Gsteels,itissmall.Throughsystematicinvestigation,itisconcludedthatstrainrateofametalduringweldingcanbeloweredandtheresistancetosolidificationcrackcanbeenhancedbyreducingstructrualrestraintandbyadjustmentofweldingparameters.

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简介：Thedynamicstressintensityfactorofathree-dimensionalellipticcrackunderimpactloadingisdeterminedwiththefiniteelementmethod.Thecomputationresultscantakeintoaccounttheinfluenceoftimeandtheratioofthewavespeedsonthestressintensityfactor.Thepresentmethodissuitablenotonlyforthree-dimensionaldynamiccrack,butalsoforthree-dimensionaldynamiccontact.

简介：Thesystemofawedgedisclinationdipoleinteractingwithaninternalcrackwasinvestigated.Byusingthecomplexvariablemethod,theclosedformsolutionsofcomplexpotentialstothisproblemwerepresented.Theanalyticformulaeofthephysicsvariables,suchasstressintensityfactorsatthetipsofthecrackproducedbythewedgedisclinationdipoleandtheimageforceactingondisclinationdipolecenterwereobtained.Theinfluenceoftheorientation,thedipolearmandthelocationofthedisclinationdipoleonthestressintensityfactorswasdiscussedindetail.Furthermore,theequilibriumpositionofthewedgedisclinationdipolewasalsoexamined.Itisshownthattheshieldingorantishieldingeffectofthewedgedisclinationtothestressintensityfactorsissignificantwhenthedisclinationdipolemovestothecracktips.

简介：Anin-depthinvestigationismadeontheproblemofanarc-shapedinterfaceinsulatingcrackinathree-phaseconcentriccircularcylindricalpiezoelectriccompositeconstitutivemodel.Anexactsolutioninseriesformisderivedbyemployingthecomplexvariablemethod.Inaddition,thedistributionofphysicalquantitiessuchasstresses,strains,electricdisplacementsandelectricfieldsinthewholefieldandalongtheinterfaceisalsopresented.Explicitexpressionsforcrackopeningdisplacement,jumpinelectropotentialonthecracksurfaceandtheelectro-elasticfieldintensityfactorsatthecracktipsareobtained.Specificcalculationsdemonstratethattheconvergenceoftheseriesformsolutionissatisfactoryandthattheouterphase(compositephase)willexertasignificanteffectontheelectro-mechanicalcouplingresponseofthecompositesystem.Owingtothefactthatstressesandelectricdisplacementsstillpossessconventionalinversesquarerootsingularities,theoscillatingsingularitiesnearthecracktipunderplanestrainconditionswillbeabsentand,asaresult,nounphysicalinterpenetrationphenomenonofthetwocracksurfaceswilloccur.Inconclusion,theelasticsolutionobtainedisalsobasedonasolidphysicalfoundation.

简介：Anaccuratecracksurfaceopeningdisplacementformulaforedgecracksinfinitebodieshasbeenderived,andwassubsequentlyusedtodevelopwide-rangeclosed-formweightfunctionsforedgecracks.Theanalyticalweightfunctionisgeneralandcanbeeasilyusedtodetermineaccuratestressintensityfactorsandcracksurfaceopeningdisplacementsforarbitrarilyloadededgecrackswithhighefficiency.Exampleshavebeengivenforproblemsofedgecrack(s)withanumberoftypicalloadconditionsforillustration.