In this dissertation, one of the mechanical characteristics of nano-structural Aluminum named "Nanoindentation" has been investigated. The method is based on semi continues fundamentals. The aluminum plate is made up of Accumulative Roll Bonding. In Accumulative Roll Bonding, the plate thickness too decreases and so the strains are too large. Then two sheets placed over each other and the process continued to gain the nano-structure material. The great characteristics of nano-structural materials such as, high strength, proper flexibility, fatigue resistance, wear resistance, high stiffness, high penetration, optical and magnetic characteristic, has made their wide usage at electronic, automobile, aviation and military industries. Daily increasing demands for new products in field of nano, forced each country to work on this new branch of science and industry. Mechanical behavior of nano-structural materials is recently worked by researchers. Controlled experiments in nano scale and atomic simulation methods like molecular dynamics, particularly for large scale problems, are nearly impossible. So multi scale models like semi continues are widely used and are approved as the most successful methods. The dissertation concentrates on multi scale modeling because of its efficiency. Semi continues is itself a multi scale method and is based on considering some of the atoms and ignoring the other ones, to simulate the mechanical behavior of material. This method logically decreases the system's degrees of freedom, so calculation the force and energy is so fast. In some areas all the atom's details considered as required and in some others the continues assumptions made.
