Multi-scale simulation of the nano-metric cutting process

Abstract

Molecular dynamics (MD) simulation and finite element (FE) method are two popular numerical techniques for the simulation of machining processes. The two methods have their own strengths and limitations. The MD simulation can cover the phenomena occurring at nanometric scale lengths but limited by the computational cost and capacity, while FE method is suitable for modelling the meso to macro scale machining and for simulating macro parameters such as the temperature in a cutting zone, the stress/strain distribution and cutting forces, etc. With the successful application of multiscale simulations in many research fields, the application to simulate machining processes is emerging particularly in relation to the machined surface generation and integrity formation, i.e. the machined surface roughness, residual stress, microhardness, microstructure and fatigue.Based on the Quasicontinuum (QC) method, the multiscale simulation of nanometric cutting has been proposed. Cutting simulations are performed on single crystal aluminium to investigate the chip formation, generation and propagation of the material dislocation during the cutting process. In addition, the effect of the tool rake angle on cutting force and internal stress under the workpiece surface is investigated. The cutting force and internal stress in the workpiece material decrease with the increase of the rake angle. Finally, to ease and speed up multiscale modelling and simulation steps, a computing efficient MATLAB-based program has been developed, which facilitates the geometrical cutting modelling, simulation conditions, implementation of simulation and results analysis within a unified integrated virtual simulation environment.

Modeling of machining of composite materials: A review

“…Amongst them the QC approach has been used only for 2-D machining of single crystal materials along with no experimental validation [92,93]. Another approach to hybridizing MD and FE is through hierarchical modeling as shown by Aly et al [94] while simulating the micromachining of silicon.…”

“…Sun et al [91] demonstrated the capabilities of the QC approach by studying the cutting of single crystal copper, while Shiari et al [92] conducted 2-D simulations on cutting of single crystal aluminum. Sun and Cheng [93] later examined the chip formation and propagation of atomistic dislocations on nanometric cutting of single crystal aluminum. All these studies have so far only demonstrated the ability of the QC method to simulate micromachining and no experimental validation has been undertaken.…”

Investigation of a scale-up manufacturing approach for nanostructures by using a nanoscale multi-tip diamond tool

“…In order to bridge the gap between the atomistic and continuum scale, multi-scale modelling method has been developed by hybridizing the FE and MD simulations [16]. These studies have made significant contributions towards the in-depth understanding of the mechanism of nanometric cutting of copper.…”

Numerical Modelling of Multilayered Coatings – Latest Developments and Applications

“…The aforementioned QC methods, based on a combined MD-FE technique, can be applied to a multiscale modelling simulation, where MD is only used in localized regions in which the atomic-scale dynamics are important, and a continuum simulation (FE) used everywhere else. For instance, Sun et al [121,122] have applied QC methods to simulate the nanometric cutting of crystal copper. Their study demonstrated that multi-scale simulation is feasible, not withstanding that there is still more work needed to be done to make multi-scale simulation more practical.…”