پديد آورنده :
سوداوي، حسين
عنوان :
بررسي رشد ترك خوردگي - خستگي در سطح خارجي لوله هاي نفت و گاز در محيط هاي با PH نزديك خنثي به كمك روش اجزاء محدود
مقطع تحصيلي :
كارشناسي ارشد
گرايش تحصيلي :
طراحي كاربردي
محل تحصيل :
اصفهان:دانشگاه صنعتي اصفهان،دانشكده مكانيك
صفحه شمار :
نه،93،[II]ص.: مصور،جدول،نمودار
يادداشت :
ص.ع.به فارسي و انگليسي
استاد راهنما :
محمدرضا فروزان
استاد مشاور :
احمد ساعتچي
توصيفگر ها :
ترك خوردگي تنش , خط لوله , تنش پس ماند , Scc , مكانيك شكست , لوله هاي اسپيرال
تاريخ نمايه سازي :
88/7/13
استاد داور :
محمود سليمي، محمد مشايخي
چكيده فارسي :
به فارسي و انگليسي: قابل رويت در نسخه ديجيتالي
چكيده انگليسي :
An Investigation into fatigue corrosion on outer surface of oil gas pipeline on near neutral pH environment using FEM Hossein sodavi H sodavi@me iut ac ir April 21 2009 Department of mechanical Engineering Isfahan University of Technology Isfahan 84156 83111Degree M Sc Language FarsiM R Forouzan Assist Prof Supervisor Forouzan@cc iut ac irAbstractLast at attention has brought to the failure of oil gas pipelines which fatigue stress corrosion cracking SCC Thisphenomenon generally happen suddenly and dangerously Even small considerable changes on internal pressure ofoil gas in transfer pipeline will lead to fatigue in the pipe Combining the fatigue and stress corrosion leads tofatigue stress corrosion Failure rate caused by this phenomenon is higher than fatigue and stress corrosion and iscommonly takes places in the near neutral pH environments In this study the life time of buried oil gas pipescalculation is investigated Outer surface cracks in different sections of the pipe near welding line as well as crackson the welding line are considered Residual stresses due to welding process make critical cracks around weldingline Cracks with different dimensions are modeled in Finite element software ABAQUS and the least dimensionsof the crack to initiate fatigue stress corrosion are calculated Then pipes with different welding conditions areinvestigated and critical sections are determined also the effect of reducing residual stresses due to welding on thelife time and the position of the critical crack is determined There is a time which is needed for cracks to reach acritical size and after this time cracks grow due to fatigue corrosion failure Time of this failure is also calculated The results of numerical calculations with ABAQUS engineering finite element software done in this dissertationobtained here can be mentioned and summarized as below 1 Location of Critical sections in transfer pipelines with various welding conditions is different This section are 2 3mm to 2 5mm far from welding line for the case study in here 2 The minimum size of crack to initiate fatigue stress corrosion cracking has been calculated for special condition to be 2 5mm 3 Life time of pipeline with different crack size in different welding conditions were calculated This time can be varied from 37 year to 44 year depending on residual stress from welding 4 In this phenomenon The cracks grow elliptically and the initial shape of the crack has not influence on the final crack shape Key Words Stress Corrosion Cracking Fatigue Pipeline Residual Stress Crack Growth
استاد راهنما :
محمدرضا فروزان
استاد مشاور :
احمد ساعتچي
استاد داور :
محمود سليمي، محمد مشايخي
