常溫和低溫下高強(qiáng)鋼斷裂模式的試驗(yàn)研究及數(shù)值分析.pdf

1、蘭州理工大學(xué)碩士學(xué)位論文常溫和低溫下高強(qiáng)鋼斷裂模式的試驗(yàn)研究及數(shù)值分析姓名：蘇仁權(quán)申請(qǐng)學(xué)位級(jí)別：碩士專業(yè)：結(jié)構(gòu)工程指導(dǎo)教師：王萬禎20100501AbstractIntheNorthridgeearthquakeinAmerica，1994andHyogoken。NanbuearthquakeinJapan，1995，therewerenumberofbrittlefailuresofbeamto。columncA)nnections，

2、andthatindicatedthatpeople，scognitionsonthestressbehavioranddamagemechanismofstructuralsteelwereratherinadequateAsanimportantprobleminmanyindustries，crackplayavitalr01einbearingcapacityandoperationallifespanofstructuralm

3、embers，andthereisnoexceptioninsteelstructureInordertoavoidthetheUnitedStatesandJapansetupspecializedpersonnelcasualtyandthepropertydamage，researchinstitutionsandproposedalotofmodifiedpro舯msButwhethertheseprogramsareofeno

4、ugheffectivenessonlya脅anotherlargeearthquakecanweknowtheresulthIordertostudycrackmechanisminstresstriaxialityandfracturedesignofstructurcsteel，bVcomparingtheresultsoffractureexperimentsandnumericalsimulationswereperfb徹ed

5、ondifI饑ntthicknessofnotchedplates，plateswithholeandnotchedbarsmadeO】：higllstrengthsteelQ345，includingtennotchedplatesof4mm，fifteennotchedplates0t10ITlmtennotchedplatesof16ram，tenplateswithholeof16mm，eighteennotchedplates

6、0f26mmandtwentynotchedbarsintheroomtemperature，butinthe10wtemperature，tennotchedplatesof16mmandtwentynotchedbarsweretestTheexperimentalresultsrevealthatthecrackinitiatesatthecurvededgeofthenotchplatesorthecurvedbars，andf

7、ormsathrough—thicknessflawwhichleadssubsequentlytoveryrapidgrowthofthecrackacrosstheremainingwidthoftheplatesFracturesectionwasdarkgrayandhadmanyholesatthecenterTbincreasethethicknessofspecimen，thefractureductilitydecrea

8、sesTochangethegapsizetosharper，thecrackingductilitylessthantheflatspecimenandVlCeversa，whichindicatesfractureloaddependingprimarilyonthenetsectionalareaoftherootnotchandshowsthestressreidinthecarvedsectionaffectingtothen

9、otchrootfracturestrengthThenumericalsimulatiOnanalysisofnotchedplates，plateswithholeandnotchedbarsbasedonGeneralizedYieldModelandMisesyieldmodelshowedthatcrackinitiatedatthecenterofnotchedsectionwherehadstrongstresstriax

10、ialityandexpandedtowardstwosidesalongthetllickIlessoftheplatesThe3Dstressfieldnearthenotchoftheplatespecimenspriort0fract眥e，whichwascomputedfromalarge。deformationanalysisusmgthegeneralizedhydrostaticyieldmodel，provesthea

11、ccuracyoftheproposedfracture=riterionBycomparingtheEllipsoidMetalFractureCriterion，HancockEquivalentStrainFractureCriterionWierzbickiEquivalentStrainFractureCriterionandthefirstPrincipalStressFractufeCriterionbasedonGene