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

简介：Thesingularboundarymethod(SBM)isarecentmeshlessboundarycollocationmethodthatremediestheperplexingdrawbackoffictitiousboundaryinthemethodoffundamentalsolutions(MFS).Thebasicideaistousetheoriginintensityfactortoeliminatesingularityofthefundamentalsolutionatsource.Themethodhassofarbeenappliedsuccessfullytothepotentialandelasticityproblems.However,theSBMsolutionforlarge-scaleproblemshasbeenhinderedbytheoperationcountofO(N~3)withdirectsolversorO(N~2)withiterativesolvers,aswellasthememoryrequirementofO(N~2).Inthisstudy,thefirstattemptwasmadetocombinethefastmultipolemethod(FMM)andtheSBMtosignificantlyreduceCPUtimeandmemoryrequirementbyonedegreeofmagnitude,namely,O(N).Basedonthecomplexvariablerepresentationoffundamentalsolutions,theFMM-SBMformulationsforbothdisplacementandtractionwerepresented.Numericalexampleswithuptohundredsofthousandsofunknownshavesuccessfullybeentestedonadesktopcomputer.TheseresultsclearlyillustratedthattheproposedFMM-SBMwasveryefficientandpromisinginsolvinglarge-scaleplaneelasticityproblems.

简介：‘Stent对stent’研究是被设计与以前同意的相比显示出新stent图案的优势的一种使随机化的试用。这些研究被规章的机构通常使用，例如美国食物药品管理局(食物及药品管理局)，到表示同意到新stent图案。有这些临床的试用的问题是他们的高费用和困难。在这份报纸，为‘stent对stent’的一种数字选择复杂临床的研究被介绍。一个有限元素模型被开发在冠的stent放置以后在结果上调查stent设计的影响。二商业地可得到的stents(NIR和多连接stents)被建模，他们的行为以压力分发在推广期间被比较，光线的获得，外部直径变化并且节略。而且，狭窄率上的stent设计的效果被在动脉以内比较压力分发调查。在stented动脉的动脉的墙压力的分析显示多连接stent设计原因与slotted试管NIR设计相比与局部性的stenotic损害降低应力到一个动脉粥样硬化患者容器。有观察临床的狭窄的调查结果相互关联与多连接stent设计相比在NIR评估狭窄率，它更高报导了。

简介：TheKarhunen-Loeve(KL)expansionandprobabilisticcollocationmethod(PCM)arecombinedandappliedtoanuncertaintyanalysisofrockfailurebehaviorbyintegratingaselfdevelopednumericalmethod(i.e.,theelastic-plasticcellularautomaton(EPCA)).TheresultsfromthemethoddevelopedarecomparedusingtheMonteCarloSimulation(MCS)method.ItisconcludedthatthemethoddevelopedrequiresfewercollocationsthanMCSmethodtoobtainveryhighaccuracyandgreatlyreducesthecomputationalcost.Basedonthemethod,theelastoplasticandelasto-brittle-plasticanalysesofrocksundermechanicalloadingsareconductedtostudytheuncertaintyinheterogeneousrockfailurebehaviour.

简介：Aninvestigationismadeonthesoilpressureinaninecabinopenedbottomellipticalbarrelstructure.Thecalculationmodelsusingthepenetrationofnegativepressuremethodhavebeendeveloped.Thefirstcalculationmodelisisfortheconstructionstageinvolvingthreezones,namely,passive,transitional,andactiveestablishedforthesoilpressureincabins.Theothercalculationmodelisbasedontheusestage,withthetwo(passiveandactive)zonesforthesoilpressureincabins.Theheightofzonesandthetheoreticalanalyticalsolutionsofinnersoilpressurearederived.Theanalyticalformulasofthemodelsareprovedusingthefiniteelementmethodandexperimentaldata,andtheformulasareanalyzedintheinnersoilpressureinthesamecondition.Thecalculationmodelscanbeusedforothermulti-positionstructuraldesignorconstruction.

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