非標(biāo)準(zhǔn)楔入劈拉試件研究混凝土的斷裂參數(shù).pdf

1、大連理工大學(xué)碩士學(xué)位論文非標(biāo)準(zhǔn)楔入劈拉試件研究混凝土的斷裂參數(shù)姓名：陳晉申請學(xué)位級別：碩士專業(yè)：結(jié)構(gòu)工程指導(dǎo)教師：趙艷華20091219非標(biāo)準(zhǔn)楔入劈拉試件研究混凝土的斷裂參數(shù)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