پديد آورنده :
حسن پور، كوروش
عنوان :
بررسي رفتار ويسكوالاستيك- پلاستيك مواد پليمري والاستومري در تغيير شكل هاي بزرگ به روش اجزاء محدود
گرايش تحصيلي :
طراحي كاربردي
محل تحصيل :
اصفهان: دانشگاه صنعتي اصفهان، دانشكده مكانيك
صفحه شمار :
چهارده، 131، [II] ص.: مصور، جدول، نمودار
يادداشت :
ص.ع. به: فارسي و انگليسي
استاد راهنما :
سعيد ضيايي راد
استاد مشاور :
مجتبي مخرون
توصيفگر ها :
ويسكوالاستيسيته , عينيت , گسسته سازي سينماتيك
تاريخ نمايه سازي :
14/12/87
استاد داور :
محمود موسوي مشهدي، حسين حسيني تودشكي، حميد هاشم الحسيني، محمد مشايخ،مجمود كدخدايي
كد ايرانداك :
ID222 دكتري
چكيده فارسي :
به فارسي و انگليسي: قابل رؤيت در نسخه ديجيتال
چكيده انگليسي :
AbstractThe thesis represents the linear and nonlinear formulations of viscoelastic behaviour Firstly in the first four chapters the basis of continuum mechanics viscoelasticitytheory and finite element method in large deformations which are used in the otherparts of the research are briefly described Polymers and elastomers representimportant viscoelastic behaviour However the pure viscoelastic behaviour inpolymers is in a limited range and then the material exhibits the viscoelastic plasticbehaviour In the fifth chapter of the thesis a phenomenological three dimensionalviscoelastic plastic constitutive model for polymers is presented The model is basedon the assumption that stress can be decomposed into two parts namely viscoelasticand elastic plastic The proposed rate dependent nonlinear model is thenimplemented in a finite element FE program The validity of the code is assessedby the data from experiments on a specific polymer The data from three types oftests namely uniaxial compression creep and relaxation are used to evaluate thevalidity of the model Comparisons show that the proposed constitutive model couldsatisfactorily represent the time dependent mechanical behaviour of polymers Themodel is then used to study the effect of friction in the compression test and thebehaviour of polymers under cyclic loading The viscoelastic behaviour in elastomers is in a larger range and the plastic behaviouris almost negligible The sixth chapter of the thesis concerns with the formulationand constitutive equations of finite strain viscoelastic material using multiplicativedecomposition in a thermodynamically consistent manner For modeling theconstitutive properties of viscoelastic solids in the context of small deformations theso called three parameter solid is often used The differential equation governing themodel response may be derived in a thermodynamically consistent way consideringlinear spring dashpot elements The main problem in generalizing constitutivemodels from small to finite deformations is to extend the theory in athermodynamically consistent way so that the second law of thermodynamicsremains satisfied in every admissible process Based on the proposed constitutiveequations a finite element procedure is developed and implemented in an FE code Subsequently the code is used to predict the response of elastomer bushings Thefinite element analysis predicts displacements and rotations at the relaxed statereasonably well The response to coupled radial and torsional deformations is alsosimulated
استاد راهنما :
سعيد ضيايي راد
استاد مشاور :
مجتبي مخرون
استاد داور :
محمود موسوي مشهدي، حسين حسيني تودشكي، حميد هاشم الحسيني، محمد مشايخ،مجمود كدخدايي
