Introduction

Metallic materials are widely used in engineering designs for structural components. Testing their mechanical properties within microscopic point of view is quite difficult in real life. In addition, it is quite possible to miss insights of phenomena of molecular level, such as evolution of formed defects and occurrence of microscopic fracture. This module representing the tensile test serves as an appropriate simulation tool for studies of microscopic crystal behavior. The module can give the general description of microscopic materials. Toughness, strength, or ductility of the material can be explained by results from simulations.

The system consists of 198 spherical atoms of triangular shape of array or 200 spherical ones of square shape of array in a two dimensional rectangular boundary. They are undergoing molecular dynamics based on truncated Lennard-Jones potentials. Changeable properties are the well depth and the truncation of the potential. Atoms are affected by external and tensile harmonic forces of opposite directions. Changeable property is the harmonic force constant. The system can be set as isothermal with changeable temperatures or adiabatic. Dynamic plots show load-versus-elongation curve for the instant response of the system and stress-versus-strain curve for the broad view of the stress-strain relationship. Instantaneous and average values of load, elongation, stress, strain and gage length of the system are presented in a table. Many different simulations can be performed to catch different qualitative and quantitative fracture mechanisms. The observed results from the simulation are consistent with expectations from the elastic theory.

This module is applicable to material science courses for the undergraduate and graduate levels