Nanostructuresare structures that their properties change with resizing dimensions and this means nanoscale material properties are different than normal state. Nanotechnology bynew looking at the devices, systems and materials that have been made so far, tried to fix their defects.In the definition of this technology, the manipulation and arrangement of the materials under Dimensions of 100 nm is considered. By manipulating atoms and Changes in manufacturing methods smaller, stronger and lighter materials can be made. Dimension reduction can equally lead to the enlargement and strengthening properties and features.Today,there arethree methodsforanalyzing themechanics ofnanostructures.These methods include controlled Experiment on the nanoscale, molecular dynamics simulations using a computer and using the Modified local classical theories. One of the most important structures at the nanoscale is the graphene nanosheets.some of the unique features of graphene that can be noted ,are nano-sized, high hardness and mechanical strength, high strength electrical and thermal conductivity,flexibility and magnetic properties. According to these properties of graphene, this material is highly regarded by scientists and in different areas of human life such as agriculture, medicine, electronics, traort industry, defense industries and so on.Is widely used.When a plate is affected by in-plane compressive load along its edges andthis loadapplied Gradually, in the early stage load forces are small enough to onlystrain will be experienced and plate has an stable equilibrium state therefore plate will remain flat until the load reaches a certain amount. In the amount of load that named buckling load ,Steady-state plate vanished and Sudden deformations out of plate will beoccurredthen periodic stability state that Simultaneously occurs with change in load-displacement behavior Is followed. the load that Causesbuckling of plate named critical buckling laod.In this thesis firstly, drawing out the buckling equations of nano orthotropic graphene sheets using Eringen nonlocal elasticity theory and finite difference method was used to solve these equations. Buckling of nano rectangular plate in different states of uniform and non-uniform in-plane loading was investigated. Based on the results obtained, the dimensionless non-local critical buckling load is always smaller or equal to the critical buckling equivalent classical loadvalue. Further, by increasing the fixed constraints on the boundary conditions of nano plate, small-scale effect on the dimensionless buckling load gradually increased. Keywords : buckling, single layered orthotropic nanoplates,Eringen nonlocal elasticity theory,finite difference method.
