混凝土ⅰⅱ復合型裂縫起裂準則的試驗研究

1、大連理工大學碩士學位論文混凝土ⅠⅡ復合型裂縫起裂準則的試驗研究姓名：馬廣東申請學位級別：碩士專業(yè)：結(jié)構(gòu)工程指導教師：吳智敏20071216混凝土1II復合型裂縫起裂準則的試驗研究ExperimentalInvestigationonInitialCrackingCriterionforIHMixedModeinConcreteAbstracto噸totheheterogeneityandnonlinearexhibiterinConcr

2、ete，thefractureprocessandcrackpropagationtheoryinconcreteiscomplexThecrackins吐uc嘛isusuallyundercombinedstress，whichresultsthestressfieldatthetopofcrackshoddnotabsolutelybeclassifiedasImode(opening)，orIImode(sliding)，orII

3、Imode(tearing)，butacombinedeffectofbothImodeandIImodeoreventhatofthethreeThis虹ndoffractureshouldbedefinedasmixedmodecrackInengineering，theIIImixedmodecrackoccurslargelyConsequentlythewholeprocessofcrackinitiationstablepr

4、opagationandunstablepropagationofthemixedmodefracturetogetherwi也itscorrespondingfiaetureparametershasbeenwidelyconcernedByusing10000KNprcssu陀testingmachinefivekindsoffourpointshearingbeamsofwhichdimensionsa托900200x200rij

5、an(Sxht)，1300300200n∞，1700400200ram2100500200and2500600200respectivelyhavebeentestedthroughIIImixedmodelfractureinconcrete、vitlltheradiooftheinitialcracklen殍hof02Inexperiment，loading，crackmouthslidingdisplacementandstrai

6、nCanbegatheredbythemachineofIMC，fourloadsensorswithdifferentmeasuringranges，ie0～1000kN，O～300kN。0～100kN0～50kNareusedtomeasuretheloadingandCMSDismeasuredbytheclipUltimatelytheinitialloadingcanbemeasllredbytwokindsofstraing

7、auges、稍mdifferentlengthsoflemand5cmOnthisbase，thepositionofcracktipandcrackpropagationdirectionCanbeestimatedIntheexperimentbendingdeflection正、疋ofloadingpointandCMSDaretheimportantparametersforanalyzingthefracturebehavio

8、rinconereteInstallingangleironlinkinganchortelltaleatthesideofspecimenCaneliminatetheen研broughtaboutbytransformationandreversionofthesupportinginthetestingoftransformationE、疋TheclipisappliedinthetestingofCMSDTheexperimen

9、tteststheloadingofcrackinitiationandofdestructionBesidesitcalculatesstressintensityfactorofcracktipandtestescrackangle；crackpropagationItCanbeobservedthereisanobviouslymacroprocessbeforeunstablepropagationinconereteMoreo