10479

9674

كارشناسي ارشد

طراحي كاربردي

اصفهان: دانشگاه صنعتي اصفهان، دانشكده مهندسي مكانيك

1394

سيزده، 106ص.: مصور، جدول، نمودار

محمود كدخدايي

مهدي سلماني تهراني

1394/07/11

محمد مشايخي، مصطفي جمشيديان

مهندسي مكانيك

ID9674

به فارسي و انگليسي

017 Finite Element Simulation of Ferromagnetic Shape Memory Alloys under Magneto Mechanical Loadings Siavash Jafarzadeh s jafarzadeh@me iut ac ir Date of Submission 2015 08 17 Department of Mechanical Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language FarsiSupervisor Mahmoud Kadkhodaei kadkhodaei@cc iut ac irAbstract Ferromagnetic shape memory alloys FSMA are a category of smart materials which go under largestrains when they are imposed to magnetic field and or compressive stress This special characteristicmakes these alloys which are known for less than two decades suitable candidates for use in sensors andactuators In recent years several constitutive models with various approaches have been proposed for thecoupled magneto mechanical behaviour of these materials However few numerical and FEM analyseswith limited functionality have been conducted on these alloys In this research a user friendly method forfinite element simulation of FSMA is proposed which can be used for general applications In this regard an explicit constitutive model is modified to obtain enhanced functionality then it is implemented to amaterial user subroutine in the commercial FE software ABAQUS According to available experimentalfindings and geometry proportions an enhanced phase diagram is introduced for NiMnGa The constitutivemodel is modified so that it can predict the response of NiMnGa in various magneto mechanical loadingswhen magnetic field and stress are applied perpendicularly Due to the fact that ABAQUS does not haveany option to analyze magneto mechanical problems as default innovative methods are used to implementthe model in user subroutines To simulate these alloys under biaxial compression a particular model isimplemented in another user subroutine To verify the enhanced model and the introduced implementationmethods reported experimental results are used Afterwards a spring actuator and a push push actuator aresimulated as two well known applications of FSMA based actuators Furthermore by using FEM analysis it is shown that how geometrically grading can increase the controlability of these materials As anothercase study the influence of changes in the distance between a NiMnGa specimen and a magnetic source onthe induced mechanical response is investigated Keywords Ferromagnetic shape memory alloys Magneto mechanical behaviour Phase diagram Finite element simulation ABAQUS Subroutine

محمود كدخدايي

مهدي سلماني تهراني

محمد مشايخي، مصطفي جمشيديان