非標準楔入劈拉試件研究混凝土的斷裂參數.pdf

1、大連理工大學碩士學位論文非標準楔入劈拉試件研究混凝土的斷裂參數姓名：陳晉申請學位級別：碩士專業(yè)：結構工程指導教師：趙艷華20091219非標準楔入劈拉試件研究混凝土的斷裂參數ResearchonfractureparametersfornonstandardwedgesplittingspecimenofconcreteAbstractWiththeextensiveapplicationofconcretestructuresfrac

2、turemechanicsofconcretehasalsobeenfurtherdevelopedinrecentyears，theresearchonthefracturepropertiesofconcretehasbeenextensivelytakenseriouslyHowever，concreteisamultiphasecompositematerial，differentfromtheidealbrittlemater

3、ials，thefractureprocessofconcreteshowsthreetypicalstages：crackinitiationcrackstablepropagationandunstablepropagationTherefore，studyingthecrackinitiationunstableandcorrespondingresistancecurvehasbeenwidelyconcemedInallusi

4、ontotheseproblems，thefollowingresearchworkhadbeenaccomplished1Thewedgesplitting(ws)testisoneofthemostwidelyusedformstoperformfracturemechanics，butthereisnospecificallycalculateexpressionofthestressintensityfactorforwedge

5、splittingtestnomatteritiSstandardornonstandardWi也testsimulationonnonstandardwedgesplittingspecimenexpressionswereproposedforstressintensityfactorattheprecasttipandcrackmouthopeningdisplacementontheloadlineforspecimen謝mdi

6、fferentdepthandinitiationcracklengthandtheirvalidityhasbeenconfirmedbycomparisonwiththedataintheliteratureBasedontheworkabove，sizeeffectontheunstablefracturetoughnessandcrackextensionwereinvestigated，andtheconsistencyoff

7、racturetoughnessdataforvariousspecimendepth嬲wellasinitiationcracklengthisdemonstratedThecrackextensionislittlesensitivetotheinitiationcracklengththough，itincreasesalongwinlthedepthofspecimenwhichCanbeexplainedbythebounda

8、ryinfluenceofthespecimen2Accordingtotheload—straincurvemeasuredintheexperiment，obtaintheinitialcrackingload，andcalculate’theinitialfracturetoughnessusingtheexpressionofthestressintensityfactorforwedgesplittingtestfoundth

9、atusingthisformulatocalculatetheinitialfracturetoughnessislittlesensitivetosizeeffect；Comparingtheinitialfracturetoughnessmeasuredbyexperimentwiththeinitialfracturetoughnessevaluatedbyananalyticalmethod，foundthatthelatte