Computational nanomechanics investigation techniques

Abstract

Today, many fields of rapidly growing research about nanomaterials and nanodevices are dependent on a combined detailed investigation between nanoscience and engineering. Hence, current nanotechnological engineering requires a vital linkage between fundamental research about the nature of the materials, which should be sought in nanoscience, and engineering investigation tools through simulations and modeling in computational nanomechanics. This linkage is necessary to obtain a comprehensive picture of the properties and characteristics of the studied nanomaterials and nanodevices under various conditions. In this chapter, a review of the fundamental concepts of the Newtonian mechanics, including Lagrangian and Hamiltonian functions is provided first. The developed equations of motion of a system with interacting material points are introduced then. After that, based on the physics of nanosystems, which can be applicable in any material phases, basic concepts of molecular dynamic simulations are introduced. Some interatomic potentials from which Morse function is recognized as an accurate definition are discussed in the next step for defining the natural bond length. With the purpose of decreasing computational effort, the cut-off radius is considered to limit atomic interactions to immediate neighbors only. The link between molecular dynamics and quantum mechanics is then explained using a simple classical example of two interacting hydrogen atoms, and the major limitations of the simulation method are discussed. Length and timescale limitation of molecular dynamics simulation technique are the major reasons behind opting multiscale simulations rather than molecular dynamics, which are explained briefly at the final sections of this chapter.