简介：这篇论文处理我击碎的模式在用精细的数字波纹技术的飞机压力状况下面的一张击碎的橡胶表的问题。通过自动化穗分析的四个转移stepphase方法，在Cartesiancoordinate系统的排水量地被给。由并列变换的方程，在极的坐标系统的光线、圆形的排水量分布被获得。裂缝尖端附近的排水量isolinedistributions和排水量向量分布被讨论。裂缝尖端附近的strainisoline分布也在这篇论文被分析。最后，分发近为机械域裁定裂缝尖端与部门部门方法被讨论。

简介：AhighMwofPLLAwassynthesized,itintendedtobeusedinthemanufactureofbioabsorbablescrewappliedinbonefractureinternalfixation.Theopticalreactionconditionshavebeendiscussed.

简介：Aclosed-formsolutionforpredictingthetangentialstressofaninclusionlocatedinmixedmodeⅠandⅡcracktipfieldwasdevelopedbasedontheEshelbyequivalentinclusiontheory.Thenamixedmodefracturecriterion,includingthefracturedirectionandthecriticalload,wasestablishedbasedonthemaximumtangentialstressintheinclusionforbrittleinclusioninducedfracturematerials.Theproposedfracturecriterionisafunctionoftheinclusionfracturestress,itssizeandvolumefraction,aswellastheelasticconstantsoftheinclusionandthematrixmaterial.Thepresentcriterionwillreducetotheconventionaloneastheinclusionhavingthesameelasticbehaviorasthematrixmaterial.Theproposedsolutionsareingoodagreementwithdetailedfiniteelementanalysisandmeasurement.

简介：在动态破裂性质和玻璃的失败机制上装载率的效果在我折断的模式下面的增强纤维的合成材料被学习。动态反射苛性的实验被执行因为二装载评价。由在苛性的实验期间测量阴影点的典型尺寸，动态SIF被计算因为不同装载评价。试验性的结果显示动态破裂坚韧与增加装载率，和裂缝显著地调笑增加在高速度的影响下面变得更快。而且由检验裂缝生长线路和破裂表面，装载的率极大地也影响失败机制在，这被显示出微规模。

简介：在现在的纸，用MMB(弯曲的混合模式)调查的CFRP的interlaminar破裂坚韧上的碳nanofiber的影响测试。蒸汽成年的碳纤维VGCF和VGCF-S，和多围的碳nanotubeMWNT-7被采用了因为CFRP上的夹层的toughener把压成薄片。以便评估破裂坚韧和它的混合模式比率，两倍弯曲的伸臂横梁(DCB)测试，结束notched破裂(ENF)测试和混合模式(MMB)测试被执行了。边界元素分析被用于CFRP模型计算interlaminar破裂坚韧，在推测方法被用来决定破裂坚韧并且混合了模式比率的地方。interlaminar破裂坚韧和混合模式比率能被压力分发在CFRP的裂缝尖端的附近外推把压成薄片。CFRP的interlaminar破裂坚韧把压成薄片，这被发现被改进插入碳nanofiber特别在砍的区域做的夹层模式变丑是主导的。

简介：Aunifieddamageandfracturemodel,thecombinatoryworkdensitymodel,whichissuitableforei-thernon-crackedbodyorcrackedbodyhasbeensuggested.Inthepresentpaper,thedeformationandfractureofthetwokindsoftensilespceimenandTPBspecimenmadeof40Crsteelhavebeensimulatedbyusingthenewmod-eltogetherwiththelargeèlastic-plasticdeformationfiniteelementmethod.Theresultsgiveagoodpictureofthewholedeformationandfractureprocessesofthespecimensinexperiments;especially,theresultsontheTPBspecimencanbeusedtoobtaintherelationshipbetweenloadanddisplacementattheloadingpointP-Δ,andbetweencrackex-tensionanddisplacementattheloadingpointΔα-Δ,theresistancecurveJR-ΔaandthefracturetoughnessJIC.Alltheresultsareinremarkableagreementwiththoseobtainedbyexperiments.Thereforethemodelsuggestedherecanbeusedtosimulatecrackinitiationandpropagationinnon-crackedbodyandfractureinitiationandcrackstablepropa-gationincrackedbody.

简介：在多孔的媒介和液体之间的热和集体转移是一个复杂联合过程，它广泛地在设计应用的各种各样的地里被使用，特别为在油和煤气的抽取的自然、人工的破裂。在这研究，一个新方法被建议在破裂处理流动和稳定的流动的热转移问题。在破裂的液体流动用象Mohais的一样的方法被描述，与多孔的墙，和不安方法把破裂看作了一条隧道的人，被用来解决数学模型。不同于以前的研究，shear跳Ochoa-Tapia和Whitaker建议的边界状况在在液体和多孔的媒介之间的接口被使用。主要方法是不安分析和申请砍跳边界条件。渗透的影响，隧道宽度，砍跳在隧道的流动和热转移上的度和有效动态粘性被分析分析答案学习。在有典型参数和热转移的敏感的变化的隧道的轴的速度的分发被获得。

简介：这研究试图调查trabecular的地区性的变化，以及决定在trabecular之间的关系词法参数和大腿骨的头的机械参数词法、机械的参数。从有折断的近似腿节的病人的七个大腿骨的头用一个micro-CT系统被扫描。每个大腿骨的头根据trabecular取向被划分成12个分区。一\(125\，\hbox{公里}^{3}\)trabecular立方的模型从每个分区被重建。81个trabecular模型的一个总数被重建，除了从在外科期间的二个大腿骨的头的三个破坏分区。Trabecular词法参数，即trabecular分离(Tb.Sp)，trabecular厚度(Tb.Th)，特定的骨头表面(BS/BV)，骨头体积部分(BV/TV)，结构的模型索引(SMI)，和anisotropy(DA)的度被测量。微有限的元素分析被执行让每个立方体获得明显的幼仔模量，织物水平von协定在1%下面强调分发沿着三个直角的方向的压缩紧张分别地。结果在词法参数揭示了重要地区性的变化(\(P)。沿着trabecular取向的幼仔moduli比沿着另外的二个方向的那些显著地高。一般来说，trabecular在中间的区域的机械性质是比在侧面的区域的那些低的。沿着trabecular取向的Trabecular机械参数显著地与BS/BV，BV/TV，Tb.Th，和DA被相关。在这研究，在有近似腿节骨折的病人的大腿骨的头的微结构特征和机械性质的地区性的变化彻底地在组织水平被调查。这研究的结果将帮助阐明为减少破裂风险和发展中的治疗策略为的大腿骨的头骨折的机制老。

简介：

简介：Acomprehensivetreatmentoffractureoffunctionallygradedmaterials(FGMs)isprovided.Itisassumedthatthematerialpropertiesdependonlyonthecoordinateperpendiculartothecracksurfacesandvarycontinuouslyalongthecrackfaces.Byusingalaminatedcompositeplatemodeltosimulatethema-terialnon-homogeneity,analgorithmforsolvingthesystembasedonLaplacetransformandFouriertransformtechniquesispresented.Unlikeearlierstudiesthatconsideredcertainassumedpropertydistributionsandasinglecrackproblem,thecurrentinvestigationstudiesmultiplecrackproblemintheFGMswitharbitrarilyvaryingmaterialproperties.Transientthermalstressesarepresented.

简介：

简介：Thetransientfracturebehaviorofafunctionallygradedlayeredstructuresubjectedtoanin-planeimpactloadisinvestigated.Thestudiedstructureiscomposedoftwohomogeneouslayersandafunctionallygradedinterlayerwithacrackperpendiculartotheboundaries.Theimpactloadisappliedonthefaceofthecrack.FouriertransformandLaplacetransformmethodsareusedtoformulatethepresentproblemintermsofasingularintegralequationinLaplacetransformdomain.Consideringvariationsofparameterssuchasthenonhomogeneityconstant,thethicknessratioandthecracklength,thedynamicstressintensityfactors(DSIFs)intimedomainarestudiedandsomemeaningfulconclusionsareobtained.

简介：Theproblemconsideredhereistheresponseofanon-homogeneouscompositematerialcontainingsomecrackssubjectedtodynamicloading.Itisassumedthatthecompositematerialisor-thotropicandallthematerialpropertiesdependonlyonthecoordinatey(alongthethicknessdirection).Intheanalysis,theelasticregionisdividedintoanumberofpliesofinfinitelength.Thematerialpropertiesaretakentobeconstantsforeachply.ByutilizingtheLaplacetransformandFouriertransformtechnique,thegeneralsolutionsforpliesarederived.Thesingularintegralequa-tionsoftheentireelasticregionareobtainedandsolvedbythevirtualdisplacementprinciple.Attentionisfocusedonthetime-dependentfullfieldsolutionsofstressintensityfactor(SIF)andstrainenergyreleaserate.Asanumericalillustration,thedynamicstressintensityfactorofasubstrate\functionallygradedfilmstructurewithtwocracksundersuddenlyappliedforcesoncracksfacearepresentedforvariousmaterialnon-homogeneityparameters.

简介：Onthebasisofplasticityandfracturemechanicsforquasi-brittlematerials,thisarticlepresentedaconstitutivemodelforgradualsofteningbehaviorofjointsofgeomaterials.Correspondingnumericaltestsarecarriedoutatthelocallevel.Characteristicsofthemodelproposedare1)plasticsofteninganddilatancybehavioraredirectlyrelatedtothefractureprocessofjoint,andmuchlessmaterialandmodelparametersarerequiredcomparedwiththoseproposedbyreferences;2)theprocessofdecohesioncoupledwithfrictionalslidingatbothmicro-scaleandmacro-scaleisdescribed.

简介：Finiteelementmethod(FEM)hasbeenusedtoanalyzethestressandstrainfieldsandthestresstri-axiallevelsaroundthetipofthecrackundermode-Ⅱloading.Theresultsshowthat:undermode-Ⅱloading,thedirectionofthemaximumtensilestressandthatofthemaximumtri-axiallevels(R_)existatanangleof-75.3°fromtheoriginalcrackplane:themaximumshearstressandR_=0existalongtheoriginalcrackplane.Mode-ⅡloadingexperimentusingBHW-35steelatdifferenttemperaturesshowthattherearetwokindsoffracturemode.openingmode(ortensilemode)andslidingmode(orshearmode).Ade-creaseintemperaturecausesthefracturemodetochangefromshearmodetotensilemode.ForBHW-35steel,thiscriticaltemperatureisabout-90C.Actually.underanykindofloadingmode(modeⅠ,modeⅡ,modeⅢormixedmode),therealwaysexistseveralkindsofpotenitalfracturemodes(forexample,openingmode.slidingmode.tearingmodeormixedmode).Theeffectoftemperatureundermode-Ⅱloadingisactuallyrelatedtothechangeoftheelastic-plasticpropertiesofthematerial.

简介：Thecharacterizationmadtestingmethodsofthedynamicfractureinitiationtoughnessofelas-tic-plasticmaterialsundertensileimpactarestudied.Byusingtheself-designedbar-bartensileimpactappa-ratus,anoveltestmethodforstudyingdynamicfracture-initiationhasbeenproposedbasedontheone-di-mensionaltestprinciple.Thecurveofaverageloadv.s.displacement（-δ）issmoothuntilunstablecrackpropagation,andthekineticenergywhichdoesnotcontributetothecrackgrowthcanberemovedfromtotalworkdonebyexternal-forcetothespecimen.Thefracture-initiationpointisdeterminedbycompliance-changingratemethod.Theresultsshowthatthesemethodsarefeasibleandeffective.Throughtheanalysisoftheconversionbetweenworkandenergyofafracturespecimen,thedynamicJ-integralisadoptedasachar-acteristicparameterforelastic-plasticmaterialsunderimpactloading.TheJ-integraliscalculatedfrom-△andP-δcurvesbyusingtheformulaproposedbyRice.TheJ-integralatfractureinitiationisemployedtodescribethedynamicfracture-initiationtoughnessofelastie-plasticmaterialsandtheexperimentalresultsindicatethatJ10canberegardedasamaterialconstant.

简介：Plainconcreteisregardedasatwo-phasematerialcomprisingrandomlydistributedaggregatesandmortarmatrix.Aseriesofthree-pointbendingconcretebeamswithsymmetricorasymmetricdoublenotchesaremodeledusingthemodifiedrandomaggregategenerationandpackingalgorithm.Thecohesivezonemodelisusedasthefracturecriterionandthecohesiveelementsareinsertedintoboththemortarmatrixandtheaggregate-mortarinterfacesaspotentialmicro-crackingzones.Thedeadandalivecrackphenomenaarestudiedexperimentallyandnumerically;andtheinfluencesofnotchlocation,aggregatedistributionandgradationonfracturearenumericallyevaluated.Someimportantconclusionsaregiven.

简介：部分地，聪明切割的过程，缺陷由尺寸描绘了的结合的效果和在切开前后的内部压力上的2纸被使用破裂力学模型学习。有大尺寸的结合的缺陷是容易的引起缺点生长的严重偏差，这被发现，当切开时，导致薄层的一个非转移的区域。在结合的缺陷的内部压力是很小的一个实际聪明切割的过程，大界面的缺点总是在切开的过程支持缺点生长。同时，增加结合的缺陷的内部压力减少在切开前的缺点生长和它的偏差。stiffener限制的松驰的机制被建议澄清结合的缺陷的效果。而且，当结合的缺陷是在场的时，切开的过程的进步被分析。在切开以后，有大尺寸和高内部的压力的那些结合的缺陷在高温度的退火期间为薄电影的blistering是脆弱的。

简介：Polymerbondedexplosives(PBXs)arehighlyparticle-filledcompositematerials.ThispaperexperimentallystudiesthetensiledeformationandfracturebehaviorofaPBXsimulationbyusingthesemi-circularbending(SCB)test.Thedeformationandfractureprocessofapre-notchedSCBsamplewitharandomspecklepatternisrecordedbyachargecoupleddevicecamera.Thedisplacementandstrainfieldsontheobservedsurfaceduringtheloadingprocessareobtainedbyusingthedigitalimagecorrelationmethod....

简介：Inthispaper,thefractureprocessofaunidirectionalCF/SiCsingleedge-notchedbeam(SENB)underthree-pointbending(TPB)isstudiedbymeansofmacro/micro-statisticalMonteCarlosimulation.Thesimulatedp-△curvesareinagreementwiththeexperimentalresultsbeforethepeaksofcurves,andthesimulatedmicroevolutionpatternsareinagreementwiththepatternsofthecracksurfaces,whichhaveverifiedthismethod.ItispreliminarilydemonstratedthatthesecondturningpointinthecompliancechangingratecurvecorrespondstothefractureinitiationforexperimentsonSENBunderTPBofunidirectionalCF/SiCcomposites.