8602

7983

كارشناسي ارشد

طراحي كاربردي

اصفهان: دانشگاه صنعتي اصفهان، دانشكده مكانيك

1392

يازده،74ص.: مصور،جدول،نمودار

ص.ع.به فارسي و انگليسي

عليرضا شهيدي

حميدرضا ميردامادي

13/12/92

حسن نحوي، صالح اكبرزاده

مهندسي مكانيك

ID7983

به فارسي و انگليسي: قابل رويت در نسخه ديجيتالي

۵ Buckling of Orthotropic Nanoscale Plates under Linearly Varying In Plane Load via Nonlocal Continuum Mechanics FatemehSadeghi fatemeh sadeghi@me iut ac ir Date of Submission 2014 01 21 Department of Mechanical Engineering Isfahan University of Technology Isfahan 84156 83111 IranDegree M Sc Language FarsiSupervisor AlirezaShahidi shahidi@cc iut ac irAbstractNanostructuresare structures that their properties change with resizing dimensions and this means nanoscalematerial properties are different than normal state Nanotechnology bynew looking at the devices systems andmaterials that have been made so far tried to fix their defects In the definition of this technology themanipulation and arrangement of the materials under Dimensions of 100 nm is considered By manipulatingatoms and Changes in manufacturing methods smaller stronger and lighter materials can be made Dimensionreduction can equally lead to the enlargement and strengthening properties and features Today there arethreemethodsforanalyzing themechanics ofnanostructures These methods include controlled Experiment on thenanoscale molecular dynamics simulations using a computer and using the Modified local classical theories Oneof the most important structures at the nanoscale is the graphene nanosheets some of the unique features ofgraphene that can be noted are nano sized high hardness and mechanical strength high strength electrical andthermal conductivity flexibility and magnetic properties According to these properties of graphene this materialis highly regarded by scientists and in different areas of human life such as agriculture medicine electronics transport industry defense industries and so on Is widely used When a plate is affected by in plane compressiveload along its edges andthis loadapplied Gradually in the early stages load forces are small enough to onlystrainwill be experienced and plate has an stable equilibrium state therefore plate will remain flat until the load reachesa certain amount In the amount of load that named buckling load Steady state plate vanished and Suddendeformations out of plate will beoccurredthen periodic stability state that Simultaneously occurs with change inload displacement behavior Is followed the load that Causesbuckling of plate named critical buckling laod In thisthesis firstly drawing out the buckling equations of nano orthotropic graphene sheets using Eringen nonlocalelasticity theory and finite difference method was used to solve these equations Buckling of nano rectangularplate in different states of uniform and non uniform in plane loading was investigated Based on the resultsobtained the dimensionless non local critical buckling load is always smaller or equal to the critical bucklingequivalent classical loadvalue Further by increasing the fixed constraints on the boundary conditions of nanoplate small scale effect on the dimensionless buckling load gradually increased Keywords buckling single layered orthotropic nanoplates Eringen nonlocal elasticity theory finite differencemethod

عليرضا شهيدي

حميدرضا ميردامادي

حسن نحوي، صالح اكبرزاده