پديد آورنده :
سمع اله، شيما
عنوان :
شبيه سازي عددي و بررسي تجربي خستگي سيم هاي آلياژ حافظه دار
مقطع تحصيلي :
كارشناسي ارشد
محل تحصيل :
اصفهان: دانشگاه صنعتي اصفهان، دانشكده مكانيك
صفحه شمار :
شانزده،96ص.: مصور،جدول،نمودار
يادداشت :
ص.ع.به فارسي و انگليسي
استاد راهنما :
محمود كدخدايي
استاد مشاور :
شبنم ارباب شيراني
توصيفگر ها :
تخمين عمر خستگي , انرژي اتلافي پايدار شده , فركانس بارگذاري , دياگرام فازي وابسته به چرخه , بارگذاري كششي , فشاري تك محوره
تاريخ نمايه سازي :
8/2/93
استاد داور :
محمد مشايخي، مهدي سلماني تهراني
چكيده انگليسي :
97 Numerical Simulation and Experimental Study of Fatigue in Shape Memory Alloy Wires Shima Sameallah shima sameallah@yahoo com January 18th 2014 Department of Mechanical Engineering Isfahan University of Technology Isfahan 84156 83111 IranDegree M Sc Language FarsiSupervisor Mahmoud Kadkhodaei kadkhodaei@cc iut ac irAbstractShape memory alloys are used in medical domain and engineering fields especially in aeronautic industries robatics civil and loom engineering due to their distinguished features than ordinary metals The lack ofknowledge caused by the inability of their fatigue life prediction extremely shows off due to the pace oftechnological developement and vast technological use of these alloys In recent decades many researchersconcentrate on study of their behavior Recently investigation of their fatigue and the effective parameters onthis phenomenon has become a popular research topic Accordingly fatigue of CuAlBe alloy and theinfluence of parameters like stress and loading frequency on its fatigue life are studied in this thesis Study ofthe loading frequency effect is one of the main aims of the present thesis since temperature variations affecttheir behavior saliently and the frequency leads to significant changes in such a sample temperature Furthermore a few authors can observe and investigate the direct effect of this parameter According todistinct behavior of the studied alloy than of NiTi usual phase diagram is modified to predict phasetransformation One of the weaknesses in scientific field of studying these alloys cyclic behavior is theabsence of a capable constitutive model to predict their behavior thus most results are experimentallyachieved In this regard the only existant and used constitutive model is formed on the base of experimentalobservations and not in a continuum framework This model has predicted fatigue life with use of aparameter called stabilized dissipated energy In the present work a fully coupled thermomechanical modelwhich is presented in a continuum framework is employed to predict the wire sample behavior and results ofthis model are compared with experimental one to verify the model After verification of the numericalresults a cycle dependent phase diagram is presented and used to formulate cycle dependent parameters inthis diagram as well as stabilized dissipated energy Finally a relation for fatigue life prediction of specimenis generated with the stabilized dissipated energy s formula In this relation the effect of stress and loadingfrequency is clearly observed on fatigue life Since tension compression test is one of the most usual andsimplest possible types of experiments the experimental results are developed by applying tensile loading onthe specimen Key WordsShape memory alloys Fatigue life prediction Stabilized dissipated energy Loadingfrequency Cycle dependent phase diagram Uniaxial tension compression loading
استاد راهنما :
محمود كدخدايي
استاد مشاور :
شبنم ارباب شيراني
استاد داور :
محمد مشايخي، مهدي سلماني تهراني
