大開孔焊接結(jié)構(gòu)中溫低周疲勞壽命估算方法的研究.pdf

1、東南大學碩士學位論文大開孔焊接結(jié)構(gòu)中溫低周疲勞壽命估算方法的研究姓名：查瓏瓏申請學位級別：碩士專業(yè)：固體力學指導教師：郭應征2002.3.1ABSTRACTWiththerapiddevelopmentofpetroleumandchemicalplants，therearemanypressurevesselswithlargeopeninginthefieldsofchemiscalindustryThereforethefatig

2、uelifepredictionofpressurevesselswithalargeopeninginthevesselstakesaespeciallyimportantpartinthesedaysThepaperstudysthemethodofestimatingfatiguelifeofpressurevesselswithlargeopeningatmediumtemperatureinlowfrequencyThewho

3、leprocessconsiststhreeaspectsThefirststep，stressdistributionofthedangerpartinpressurevesselsisinvestigatedbyANSYSSecondly，itstudysfatiguecrackinitiationlifebasedonstressdistributionAtlast，itevaluatespropagationlifeofthef

4、atiguecrackandproposesamethodforthatInconclusion，aconvenientandreliablemethodofthelow—cyclefatiguelifepredictionisbroughtforwardforpressurevesselswithlargeopeningatmediumtemperaturewhichisespeciallyefficientinthiscaseEst

5、imatingfatiguelifebyoriginalmaterialischaracteristicofthemethodanditcouldgainsafelyconclusionFinally，wewouldliketosaythatourresearchaboutestimatingfatiguenaturallireiSfarfrommatureandneedsfurtherendeavorsKeywords：Pressur