شماره راهنما :
1158 دكتري
پديد آورنده :
جعفري گلويك، محمد
عنوان :
مدل سازي ساختاري حركت مرزدانه با استفاده از روش كريستال پلاستيسيته بر مبناي چگالي نابجايي و روش ميدان فاز
گرايش تحصيلي :
طراحي كاربردي
محل تحصيل :
اصفهان: دانشگاه صنعتي اصفهان، دانشكده مكانيك
صفحه شمار :
چهارده، [۱۲۱]ص.: مصور، جدول، نمودار
استاد راهنما :
سعيد ضيايي راد
استاد مشاور :
مصطفي جمشيديان
توصيفگر ها :
معادله ساختاري , حركت مرزدانه متاثر از كرنش , كريستال پلاستيسيته بر مبناي چگالي نابجايي , ميدان فاز , چند مقياسي
استاد داور :
حسين حسيني تودشكي، محمد مشايخي، مهدي جوانبخت
تاريخ ورود اطلاعات :
1396/12/22
كد ايرانداك :
ID1158 دكتري
چكيده انگليسي :
Constitutive Modeling of Grain Boundary Migration Using Dislocation based Crystal Plasticity and Phase Field Methods Mohammad Jafari Gelooyak jafarimohammad1988@gmail com January 25 2018 Department of Mechanical Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree Doctor of Philosophy PhD Language Farsi Supervisor Prof Saeed Ziaei Rad szrad@cc iut ac ir Abstract We have developed a thermodynamically consistent finite deformation based constitutive theory to describe strain in duced grain boundary migration SIBM due to the heterogeneity of stored deformation energy in a plastically deformedpolycrystalline cubic metal Considering a representative volume element a mesoscale continuum theory is developedbased on the coupling between dislocation density based crystal plasticity and phase field methods Using the Taylor model based homogenization method a multiscale coupled finite element and phase field staggered time integration procedure isdeveloped and implemented into the Abaqus Standard finite element package via a user defined material subroutine Thedeveloped constitutive model is then used to perform numerical simulations of dynamic SIBM in polycrystalline tantalumthat microstructure evolution occurs during the ongoing plastic deformation at high temperature The simulation results areshown to qualitatively and quantitatively agree with experimental results We adapt our developed constitutive model for dynamic SIBM for the case of static SIBM For this purpose a mesoscalepolycrystalline representative volume element is sequentially subjected to simulated low temperature plastic deformationand high temperature annealing The simulations show that the kinetics of SIBM and specifically the interplay between thestored deformation energy minimizing driving force and the grain boundary curvature related capillary driving force arehighly affected by the initial average grain size as a characteristic of the microstructural length scale There is a transitionalbehavior from normal to abnormal grain growth for microstructure evolution by increasing the microstructural length scale Particularly the dominance of the curvature driving force for relatively small microstructural length scales results in theevolution of microstructure via nearly normal grain growth Abnormal grain growth occurs due to the prevailing influenceof the stored deformation energy minimizing driving force for relatively large microstructural length scales The dislocationcontent in the microstructure rapidly decreases during static SIBM and hence the predominance of the stored deformationenergy minimizing driving force is progressively moderated Therefore in this case a transition from abnormal to normalgrain growth is observed at later times of microstructure evolution Key Words Constitutive modeling Strain induced boundary migration Crystal plasticity Phasefield Multiscale
استاد راهنما :
سعيد ضيايي راد
استاد مشاور :
مصطفي جمشيديان
استاد داور :
حسين حسيني تودشكي، محمد مشايخي، مهدي جوانبخت
