混凝土構件內(nèi)現(xiàn)存應力鉆孔釋放過程的有限元模擬.pdf

1、東北大學碩士學位論文混凝土構件內(nèi)現(xiàn)存應力鉆孔釋放過程的有限元模擬姓名：劉芳申請學位級別：碩士專業(yè)：固體力學指導教師：張鳳鵬20090601FiniteelementSimulationoftheReleasingProcessofExistingStressinConcreteStructuresbyDrillingHoleMethodAbstractTheexistingstressinconcretestructuresisoneo

2、fthemostimportantparameterstepresenttheforceconditionandthereliabilityofthestructureTherefore，theexactpredictionoftheexistingprestressingforcebecomescrucialTheholedrillingmethodisaneffectivemethodofmeasuringthestressinsi

3、deconcreteAndthemethodhastheoreticalsignificanceandapplicationvalueforresearchingthereleasingprocessandthereleasingruleInthisthesis，thereleasingprocessofexistingstressinprestressedconcretestructurebytheholedrillingmethod

4、issimulatedbyfiniteelementmethodwiththeboreholediameterof120mm，theinnerdiameterofll0mm，themaximumdepthof1lOmmStrainreleasingrateisusedtodescribetheprincipleofreleasingTechniqueofelementbirthanddeathisusedtosimulatedrilli

5、ngprocessThestressreleasingrateunderuniformload，gradientforce，shearstressandpressureshearstressstateisstudiedThestrainreleasingrateundereverystressstateiscomparedandanalyzedtheinfluenceoftheprincipleofreleasingunderdiffe

6、rentstressstateAswellastheanalysisunderthedifferentload(pressureandpureshear)andthecomponentthickness，thestrainchangesandthedisciplineofstrainreleasewiththedepthofdrillingchangesTheresultsindicatethatthestrainreleasingva

7、luedependsonthestressinitialvalueandthestressconditionThestrainreleasingrateisrelatedtothedepthofhole，butnotthestressstateandloadconditionThedepthoftheholethatstresshasbeencompletelyreleaseddoesnotchangewiththestresscond

8、itionandtheinitialstressStrainreleaseandthereleaseratevaluesalsodependonthesizeofcomponentthicknessdirection；whenlargerthan150mmscantlings，thecomponentsizeisnolongerafactorintheimpactofstrainreleaseKeywords：prestressedco