Mechanical Properties Of Carbon Nanotubes In Micro / Nano Electromechanical Systems

In this thesis, the author studies the mechanical properties of carbon nanotubes in the micro/nano electrical and mechanical system (M/NEMS) by molecular dynamics simulation. Firstly, recent studies on carbon nanotubes and simulation methods of nano materials are introduced. The molecular structure and properties of carbon nanotubes are given. The potential applications of carbon nanotubes in M/NEMS are presented. Secondly, molecular dynamics simulation is reviewed. It is suggested that Tersoff-Brenner potential function is better than other potential functions in simulating carbon nanotubes. Thirdly, Basic approaches of molecular dynamics simulation, which include building the model potential, potential truncation, short-range interaction computations, integration methods, boundary conditions and so on, are studied in detail. They are discussed in detail which include preparations for data before simulating, control method during simulating, different factors related to equilibration of simulating systems, observation of atomic structure after simulating, statistic and control methods of macro characters. Fourthly, the mathematics model of single-wall carbon nanotube (SWCNT) is built. Molecular Mechanics Calculation is used to minimize the energy ofinitial model of SWCNT. The relationship of strain energy and structure of SWCNT is studied. Fifthly, thermal stability is analyzed based on optimized structure of SWCNT. Under low temperature and high temperature, tensile responses of SWCNT are probed. Young's modulus and elastic strain are showed. Finally, the main points of the whole paper are sum up and researching approaches further are given.