پديد آورنده :
آقاجاني، سپيده
عنوان :
تخمين عمر در پره هاي توربين بادي با رهيافت مدل چند مقياسي آسيب
مقطع تحصيلي :
كارشناسي ارشد
گرايش تحصيلي :
طراحي كاربردي
محل تحصيل :
اصفهان: دانشگاه صنعتي اصفهان، دانشكده مكانيك
صفحه شمار :
پانزده، ۱۰۱ص.: مصور، جدول، نمودار
استاد راهنما :
محمد مشايخي
استاد مشاور :
محمد سيلاني
توصيفگر ها :
مكانيك آسيب هم افزايي , ميكرومكانيك محاسباتي , مكانيك آسيب محيط پيوسته , آسيب خستگي , ترك ماتريسي
استاد داور :
محمدرضا فروزان، صالح اكبر زاده
تاريخ ورود اطلاعات :
1397/02/03
چكيده انگليسي :
Life Prediction Of wind Turbine Blades Using Multi scale Damage Model Sepide Aghajani S Aghajani@me iut ac ir Date of Submission 2018 03 5 Department of Mechanical Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language FarsiSupervisor Mohammad Mashayekhi mashayekhi@cc iut ac irAbstract Since the evolution of fatigue damage in composite materials currently used for large structure includingwind turbine blade was not well understood large safety factors were employed which lead to highlyconservative designs In order to improve and enhance the design confidence these structures were tested indifferent conditions which would lead to a lot of time and cost To advancing researchers used analytically andsimulation methods to design structures A lot of analytical methods have been proposed for designing andestimating the life of composite structure one of which was estimation of stiffness reduction in material becauseof damage This study investigates one simulation method based on multi scale damage mechanic Computational micromechanics was coupled within a continuum damage mechanics CDM framework andimplemented through a user de ned subroutine within commercial nite element software for evaluating sub critical damage evolution and stiffness degradation of the structure Finally VUMAT user subroutine ofABAQUS is used to determine the constitution equation in continuum damage mechanics and then is applied towind turbine blade to investigate fatigue damage mechanism using modified Puck s criteria damage is studied ina layer level of a fatigue loaded wind turbine blade Damage is investigated in fiber direction and matrix Themodel is implemented in a user material finite element subroutine to calculate damage parameter in layer level atany cycle of loading Then calculations are extended to laminate using classic layer theory New damageparameter and elastic modulus is computed at any element and finally wind turbine blade life is computed with astop criterion damage parameter of layers and layers constant are obtained to be applied on 0 90 45 45 and 0 90 laminates Then applying specified load to blade and using user subroutine code of synergistic damagemechanic saturated crack density of layers is calculated and compared to similar results of related journals Crack density of 90 45 and 45 plies are 1 1 0 75 and 0 36 respectively According to results of analysis reduced stiffness and damage parameters are calculated Finally applying fatigue damage multi axial in themulti directional composite based on modified Puck s criteria life is estimated 950000 cycles causing fracture in 45 ply at mode C In fracture cycle damage parameter is calculated in 90 45 45 plies which results in 0 99 0 82 and 0 59 respectively Keywordssynergistic damage mechanic Computational micro mechanic Continuum damagemechanics fatigue damage Matrix cracking
استاد راهنما :
محمد مشايخي
استاد مشاور :
محمد سيلاني
استاد داور :
محمدرضا فروزان، صالح اكبر زاده
