Multiscale Modeling Of Mechanical Properties Of Nanomaterials

Nano-Science and Technology brings numerous new nano-materials. One-dimensional nano-material means that there are two-dimension belongs to the nano-scale in the three-dimensional space, such as carbon nanotubes and metal nanosilk. Because of its special structure and big specific surface area, nano-material behaves a series of new effects, such as subsize effect, surface effect, quantum effect and quantum tunnel effect, which bring many distinguishing properties different from traditional materials. Only by experimentation, it is difficult to completely understand microcosmic structure, properties and intrinsic mechanism of nano-materials. With the progress of computer technology, computer simulation is widely applied to material research.In this paper, molecular dynamic method, continuum shell model and molecular structural method are adopted to study the mechanical properties of carbon nanotubes and nano-single crystal copper wires. The main contents are as follows:(1) Because of the special nanostructure, carbon nanotubes behave lots of excellent properties. The molecular dynamic method is applied to study the static or dynamic bulking of single-walled carbon nanotubes under axial loading and obtain the axial Young's modulus. Build up a cantilever beam model and analyze the radial deformation of single-walled carbon nanotubes under radial compression load.(2) The continuum shell model and molecular structural model are applied respectively to modeling static and dynamical bulking of single-walled carbon nanotubes, the critical buckling strain of different size carbon nanotubes are computed and compared with the corresponding results obtained by molecular dynamic method. The merits and drawbacks and scope of application of these methods are summed up.(3) The molecular dynamic method is applied to build a computing model of nano-single crystal copper wires and studying deformation of nano-single crystal copper wires under axial tension or compression or bending. The deforming rules of nano-single crystal copper wires are summarized.