基于有限元和斷裂力學(xué)的起重機(jī)結(jié)構(gòu)故障診斷.pdf

1、武漢科技大學(xué)碩士學(xué)位論文基于有限元和斷裂力學(xué)的起重機(jī)結(jié)構(gòu)故障診斷姓名：甘文兵申請(qǐng)學(xué)位級(jí)別：碩士專業(yè)：機(jī)械電子工程指導(dǎo)教師：龍靖宇20101116武漢科技大學(xué)武漢科技大學(xué)碩士學(xué)位論文第II頁(yè)AbstractInrecentyearsalongwiththehighlydevelopedeconomyofourcountrytheproductionofsteelrisesincreasinglytheloadwksofcraneshave

2、enlargedinmetallurgicalenterprises.Atthesametimethereappearallkindsofmetalproblems.Amongtheseproblemsthemostcommonalsothemostseriousisthetroubleincranemetalstructureswhichmostlyaretroublesoffatiguecrack.Thispaperengagein

3、theanalysisofcrackonthe7020t16.5moverheadcraneinthesecondrollingmillofMasteelCp.Ftheprimecausesofcrackontheoverheadcraneusefiniteelementmethodtoestablishthefiniteelementmethod(FEM)ofmetalstructureoftheoverheadcraneframdi

4、fferentmodelsofloadunderdifferentwkingconditionsispresentedbyfinteelementanalysisfindoutpinpointthecauseofthetroublefromthecontrastanalysisofthestaticloadsfatiguelifeonthisbasisfurtherstudyonpropagationbehaviourofoverhea

5、dcraneframfatiguecrackbynumericalanalysisprovidethetheybasisftherestationimprovementdesignoftheoverheadcranethesametype.Thispaperhascompletedthefollowingresearchwktosolvetheproblems:1)Presentstheanalysisresearchonthefram

6、metalstructurecracktofindoutthereasonsofthefractureusetheABAQUSfiniteelementsoftwaretoperfmtheoverheadcraneframmetalstructurestaticanalysisItwasfoundonanalysisthatthelargeheightdifferenceofwheelsbearingpointisthemainreas

7、onofcausingcrack.2)Mostlyresearchedextendedfiniteelementmethod(XFEM)theythecomputationalMethodofStressintensityfacts(SIFs)inrecentlytosetoffbycontrastonFEMcomputationalMethodofSIFsXFEMcomputationalMethodofSIFstoshowthehi

8、ghefficiencypracticalityofXFEMthisnewtechniqueontheSIFscalculationprovideatechnologysupptftheoverheadcraneframfatiguecrackgrowthnumericalanalysis.3)AccdingtotheyofengineeringrupturemechanicsconsidertheInitialDefectoftheo

9、verheadcranemetalstructurefatiguecrackgrowthoftheframundercyclicstressarestudiedmodelⅠmodelⅡmodelⅢStressintensityfacts(SIFs)ofcrackshavingdifferentlengtharecalculatedbyusingextendedfiniteelementmethod(XFEM)thenfatiguecra

10、ckpropagationcurvewasgainedbytheMixedModefatiguecrackgrowththeyfundamentallawsoffatiguecrackgrowthwiththeobjectofstudywasdescribedpreciselyestablishedfunctionbetweencracklengththenumberofalternatingstresscyclenumericalan

11、alysisonpropagationfeaturesofthefatiguecrack.4)Therepairplanspecificrepairmeasureswasgivedbasisonthecrackarresttheymethodcalculatedthestressesdistributionoftheframwherethedangercrackaftertherepairmenttheresultsindicatedt