偏梯形套管螺紋接頭多軸疲勞壽命研究.pdf

1、西北工業(yè)大學(xué)碩士學(xué)位論文偏梯形套管螺紋接頭多軸疲勞壽命研究姓名：吳應(yīng)喜申請學(xué)位級別：碩士專業(yè)：固體力學(xué)指導(dǎo)教師：王峰會20070301西北工業(yè)大學(xué)碩士學(xué)位論文摘要ABSTRACTCasingdrillingtechniquewhichhasbeendf鋤aticallydeVelopingisareV0lutioninpetroleumindustryandhasaroused黟eatConcemathOme鋤dabroadButitp

2、resentsanewdem鋤dforthecasingco皿ections’propertyT1Ief缸iguefajlureOfcasingtllreadCo蛐ectionsisacriticalissue觚dhasn’tbesolvednisthereforeof伊eaten酉neeringandscientificValuet0systematicallystudythefatiguefailure0fCommonlyusedc

3、asingco皿eCtionhlthispaper，thenotchedspecimensaredesigned，aCCordingtothec：haracterofthestressandstrajndistribution0fthecOnnectionsThestressstrainstateinthe翻ticalpositionfornotchedspecilIlenswascalculated鋤d觚alyzedbyel舔ticp

4、l硒ticfiniteelementmethod，柚dtllentlleobtainedrc跚ltswereusedtopredicttlle姍lti強(qiáng)ialfatigIlelifcofnotchedSpedme璐First，throughtlletensiletestingofJ55casingmatefial，thefoundamentalmechallicSparametersistested，suChasfieldstress，

5、tensileintensionetcSecond，thestIessandstrainfortheCo皿eCtionssubjectedtoproponionalloadingwefeanalyzedbyelastic—plasticfini詫elementmethodPointouttllecritiCalpositionofthreadco皿ectionnestress—strainstatefornotchedspecimens

6、subjectedtoconst孤t鋤plitudeproponionalmultiaxialloadingsw弱alsocalclllated觚d觚alyzedbythefiniteelementmOdelandthetheOreticalstressconcentrationfactOr0fthenotchedspecimenshadobtainedTlllird，aseriesofmultiaxialfatigIletestswe

7、recallriedoutonMTS858materialtestsystemfornotchedspecimensT1lefatigue脅cturesurfacesofnotchedspecimenswereobserved觚d柚alyzedACoordingtotheobservedresultsofthefatigue矗acturcsurf犯es，themech孤ismsoffatigllecrackinitiationaIldp

8、ropagationwerestudiedLast，ontllebasisOftheresultsOffiniteelementaIlalysis，sOmemultiaxialfatiguemodelswereusedtomultiaxialfatiguelifeT1lepredictedliVeswerecomparedwiththeexperimentaldataTheresultsOffatiguelifepredictionsh