简介：Formulationintermsofhypersingularintegralequationsfortheinteractionbetweenstraightandcurvedcracksinplaneelasticityisobtainedusingthecomplexvariablefunctionsmethod.Thecurvedlengthcoordinatemethodandasuitablenumericalschemeareusedtosolvesuchintegralsnumericallyfortheunknownfunction,whicharelaterusedtofindthestressintensityfactor,SIF.

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。

简介：Thepresentworkisconcernedwithapenny-shapedDugdalecrackembeddedinaninfinitespaceofone-dimensional(1D)hexagonalquasicrystalsandsubjectedtotwoidenticalaxisymmetrictemperatureloadingsontheupperandlowercracksurfaces.ApplyingDugdalehypothesistothermo-elasticresults,theextentoftheplasticzoneatthecracktipisdetermined.Thenormalstressoutsidetheplasticzoneandcracksurfacedisplacementarederivedintermsofspecialfunctions.Forauniformloadingcase,thecorrespondingresultsarepresentedbysimplifyingtheprecedingresults.Numericalcalculationsarecarriedouttoshowtheinfluenceofsomeparameters.

简介：在同类的压电的脱衣的平行裂缝的一个周期的数组的问题结合了到机能上地分级的压电的材料为不同类的连续统被调查。材料不同类沿着裂缝的方向作为在指数的功能形式的shear模量的空间变化被代表，这被假定。混合边界价值问题被使用Fourier变换归结为一个单个不可分的方程，并且单个不可分的方程被使用Gauss-Chebyshev集成技术数字地解决。数字结果被获得为材料不同类的不同的值作为裂缝频率的一个函数说明压力紧张因素的变化。

简介：Aconcurrentmultiscalemethodisdevelopedforsimulatingquasi-staticcrackpropagationinwhichthefailureprocessesoccurinonlyasmallportionofthestructure.Forthispurpose,amultiscalemodelisadoptedandbothscalesarediscretizedwithfinite-elementmeshes.Theextendedfiniteelementmethodisemployedtotakeintoaccountthepropagationofdiscontinuitiesonthefine-scalesubregions.Atthesametime,fortheothersubregions,thecoarse-scalemeshisemployedandisresolvedbyusingtheextendedmultiscalefiniteelementmethod.Severalrepresentativenumericalexamplesaregiventoverifythevalidityofthemethod.

简介：Aradialcrackemanatingfromasemi-circularnotchisofsignificantengineeringimportance.Accuratedeterminationofkeyfracturemechanicsparametersisessentialfordamagetolerancedesignandfatiguecrackgrowthlifepredictions.Thepurposeofthispaperistoprovideanefficientandaccurateclosed-formweightfunctionapproachtothecalculationofcracksurfacedisplacementsforaradialcrackemanatingfromasemi-circularnotchinasemi-infiniteplate.Resultsarepresentedfortwoloadconditions:remoteappliedstressanduniformstresssegmentappliedtocracksurfaces.Basedonacorrectionofstressintensityfactorratio,highlyaccurateanalyticalequationsofcracksurfacedisplacementsunderthetwoloadconditionsaredevelopedbyfittingthedataobtainedwiththeweightfunctionmethod.ItisdemonstratedthattheWuCarlssonclosed-formweightfunctionsareveryefficient,accurateandeasy-to-useforcalculatingcracksurfacedisplacementsforarbitraryloadconditions.Themethodwillfacilitatefatiguecrackclosureandotherfracturemechanicsanalyseswhereaccuratecracksurfacedisplacementsarerequired.

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

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

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：Theplaneproblemofacrackterminatingattheinterfaceofabimaterialpiezoelectric,andloadedonitsfaces,istreated.Theemphasisisplacedonhowtotransformthisproblemintoanon-homogeneousHilbertproblem.Tomakethederivationtractable,theconceptoftheaxialconju-gateisintroducedandrelatedtothecomplexconjugate.Theanglebetweenthecracklineandtheinter-facemaybearbitrary.Numericalresultsaregiventoillustratethestresssingularityatcracktip.

简介：Twostochasticmodelsoffatiguecrackgrowthunderconstantamplitudecyclicloadingareproposedandstudiedbyusingthestochasticaveragingmethodandtotalprobabilitytheoremtoac-countforhighfrequencycomponentandlowfrequencycomponent,respectively,oftheirregularna-tureoffatiguecrackgrowthobservedinVirkler’sexperiment.Particularattentionispaidtothepredic-tionperformanceofthemodelsunderachangeintheinitialcracklength.Itisshownthatthemodelsproposedinthepresentpaperyieldsbetteragreementwithexperimentaldatathanothermodelsavail-ableinliterature.

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简介：在这份报纸，为包含一个裂缝的机能上地分级的脱衣的飞机弹性问题被考虑。这被假定shear模量相互是厚度坐标的线性功能，当Possion的比率保持不变时。由利用Fourier转变技术和转移矩阵方法，混合边界问题被归结为数字地被解决的单个不可分的方程的一个系统。压力紧张因素和紧张精力版本率上的几何参数和分级的参数的影响被调查。数字结果证明分级的参数，长带的厚度和裂缝尺寸在压力紧张因素和紧张精力版本率上有重要效果。

简介：Themainobjectiveofthispaperistostudythesingularnatureofthecrack-tipstressandelectricdisplacementfieldinafunctionallygradientpiezoelectricmediumhavingmaterialcoefficientswithadiscontinuousderivative.Theproblemisconsideredforthesimplestpossibleloadingandgeometry,namely,theanti-planeshearstressandelectricdisplacementin-planeoftwobondedhalfspacesinwhichthecrackisparalleltotheinterface.Itisshownthatthesquare-rootsingularityofthecrack-tipstressfieldandelectricdisplacementfieldisunaffectedbythediscontinuityinthederivativeofthematerialcoefficients.Theprob-lemissolvedforthecaseofafinitecrackandextensiveresultsaregivenforthestressintensityfactors,elec-tricdisplacementintensityfactors,andtheenergyreleaserate.

简介：M积分的物理解释在损坏裂缝的压电的问题的分析被调查。在M积分和全部的电的热含量(CTEE)的变化之间的关系，即，M=2CTEE，为二维的压电的问题与一个理论推导过程被导出。M积分可以由于与损坏身体，而非对为常规易碎的固体解释了的全部的势能版本率的描述联系的pre-existingmicroc-racks的形成提供对电的热含量版本的更自然的描述，这被显示出。为损坏裂缝的压电的陶艺，M积分的数字计算被讨论。基于pseudo-tractionelectric排水量方法，M=2CTEE被数字结果也证明了。

简介：TheSelf-SimilarCrackExpansion(SSCE)methodisproposedtoevaluatestressintensi-tyfactorsatcracktips,wherebystressintensityfactorsofacrackcanbedeterminedbythecrackopeningdisplacementoverthecrack,notjustbythelocaldisplacementaroundthecracktip.Thecrackexpansionrateisestimatedbytakingadvantageofthecrackself-similarity.Therefore,theaccuracyofthecalculationisimproved.Thesingularintegralsoncracktipelementsarealsoanalyzedandarepre-ciselyevaluatedintermsofaspecialintegralanalysis.Combinationofthesetwotechniquesgreatlyin-creasestheaccuracyinestimatingthestressdistributionaroundthecracktip.Avarietyoftwo-dimen-sionalcracks,suchassubsurfacecracks,edgecracks,andtheirinteractionsarecalculatedintermsoftheself-similarexpansionrate.Solutionsaresatisfiedwitherrorslessthan0.5%ascomparedwiththeanalyticalsolutions.Basedonthecalculationsofthecrackinteractions,atheoryforcrackinteractionsisproposedsuchthatforagroupofalignedcracksthesummationofthesquareofSIFsattherighttipsofcracksisalwaysequaltothatatthelefttipsofcracks.ThistheorywasprovedbythemehtodofSelf-SimilarCrackExpansioninthispaper.

简介：Theproblemofananti-planeGriffithcrackmovingalongtheinterfaceofdissimilarpiezoelectricmaterialsissolvedbyusingtheintegraltransformtechnique.Itisshownfromtheresultthattheintensityfactorsofanti-planestressandelectricdisplacementaroundthecracktiparedepen-dentonthespeedoftheGriffithcrackaswellasthematerialcoefficients.Whenthetwopiezoelectricmaterialsareidentical,thepresentresultwillbereducedtotheresultfortheproblemofananti-planemovingGriffithcrackinhomogeneouspiezoelectricmaterials.

简介：ThescatteringofLovewavesbyaninterfacecrackbetweenapiezoelectriclayerandanelas-ticsubstrateisinvestigatedbyusingtheintegraltransformandsingularintegralequationtechniques.Thedy-namicstressintensityfactorsoftheleftandtherightcracktipsaredetermined.Itisfoundfromnumericalcalculationthatthedynamicresponseofthesystemdependssignificantlyonthecrackconfiguration,thema-terialcombinationandthepropagatingdirectionoftheincidentwave.Itisexpectedthatspecifyinganappro-priatematerialcombinationmayretardthegrowthofthecrackforacertaincrackconfiguration.

简介：ThispaperpresentsanattemptattheapplicationofcatastrophetheorytothestabilityanalysisofJ-controlledcrackgrowthinthree-pointbendingspecimens.ByintroducingthesolutionsofJ-integralinthecompletelyyieldingstatefortheidealplasticmaterial,thecriticalconditionoflosingstabilityforthecrackpropagationinthespecimenisobtained,basedonthecuspcatastrophetheory.Theprocessofthecrackgrowthfromgeometricalsenseisdescribed.

简介：Thispaperpresentsanextensionofadisplacementdiscontinuitymethodwithcracktipelements(aboundaryelementmethod)proposedbytheauthorforfatiguecrackgrowthanalysisinplaneelasticmediaundermixed-modeconditions.Theboundaryelementmethodconsistsofthenon-singulardisplacementdiscontinuityelementspresentedbyCrouchandStarfieldandthecrack-tipdisplacementdiscontinuityelementsduetotheauthor.Intheboundaryelementimplementationtheleftorrightcrack-tipelementisplacedlocallyatthecorrespondingleftorrightcracktipontopofthenon-singulardisplacementdiscontinuityelementsthatcovertheentirecracksurfaceandtheotherboundaries.Crackgrowthissimulatedwithanincrementalcrackextensionanalysisbasedonthemaximumcircumferentialstresscriterion.Inthenumericalsimulation,foreachincrementofcrackextension,remeshingofexistingboundariesisnotrequiredbecauseofanintrinsicfeatureofthenumericalapproach.Crackgrowthismodeledbyaddingnewboundaryelementsontheincrementalcrackextensiontothepreviouscrackboundaries.Atthesametime,theelementcharacteristicsofsomerelatedelementsareadjustedaccordingtothemannerinwhichtheboundaryelementmethodisimplemented.Asanexample,thefatiguegrowthprocessofcracksemanatingfromacircularholeinaplaneelasticplateissimulatedusingthenumericalsimulationapproach.