Study on nano-cutting of brittle material by molecular dynamics using dynamic modeling

Abstract

Nano-cutting of brittle material finds wide applications in scientific research and engineering. Numerical simulation is an important tool for understanding the process mechanism, which has many advantages over experimental approaches. Currently, molecular dynamics is the most used method for nano-cutting simulation owing to its explicit description of material at atomic level. However, the model scale in current studies is far smaller than the reality. As a result, cutting-induced fracture, the main surface damage in the machining of brittle material, is difficult to reveal and well understand, which has become a critical issue in the field. In this study, a novel simulation approach is proposed to improve the computing efficiency after analyzing the shortcomings of traditional model. The principle is to build a localized workpiece near the tool which is dynamically modified so that the length of workpiece in computation is reduced and the saved computer resource can be used to increase the depth of cut and the tool edge radius. A large scale simulation on germanium verifies the capability of this method and reveals the fracture damage formation during the cutting process.