A Multiscale Cutting Model Based on the Theory of Gradient Plasticity

2013 ◽  
Vol 698 ◽  
pp. 99-106
Author(s):  
Tarek Mabrouki ◽  
Jean François Rigal ◽  
Muhammad Asad
Keyword(s):  
Size Effect ◽  
Scale Effect ◽  
Material Removal ◽  
Cutting Tool ◽  
Chip Thickness ◽  
Gradient Plasticity ◽  
Model Based ◽  
Cutting Model ◽  
Orthogonal Case

The present paper highlights the importance of size effect consideration during the modelling of material removal by cutting tool, especially when passing from maco-to-micro scales. For that, the presented study concerns an orthogonal case of down-cut milling where the chip thickness is evolving. Consequently, to capture the scale effect when passing from macro to micro dimensions, the theory of gradient plasticity were adopted.

scholarly journals Cutting-based single atomic layer removal mechanism of monocrystalline copper: edge radius effect

2019 ◽  
Vol 14 (1) ◽  
Author(s):  
Wenkun Xie ◽  
Fengzhou Fang
Keyword(s):  
Material Removal ◽  
Chip Thickness ◽  
Atomic Layer ◽  
Atomic Scale ◽  
Removal Mechanism ◽  
Minimum Chip Thickness ◽  
Layer Removal ◽  
Edge Radius ◽  
Mechanical Cutting ◽  
Cutting Model

AbstractThe ultimate objective of mechanical cutting is to down minimum chip thickness to single atomic layer. In this study, the cutting-based single atomic layer removal mechanism on monocrystalline copper is investigated by a series of molecular dynamics analysis. The research findings report that when cutting depth decreases to atomic scale, minimum chip thickness could be down to single atomic layer by mechanical cutting using rounded edge tool. The material removal behaviour during cutting-based single atomic layer removal exhibits four characteristics, including chip formation by shearing-stress driven dislocation motion, elastic deformation on the processed surface, atomic sizing effect, and cutting-edge radius effect. Based on this understanding, a new cutting model is proposed to study the material removal behaviour in cutting-based single atomic layer removal process, significantly different from those for nanocutting and conventional cutting. The outcomes provide theoretical support for the research and development of the atomic and close-to-atomic scale manufacturing technology.

Experimental investigation of a slip-line field model for a worn cutting tool

2013 ◽  
Vol 228 (8) ◽  
pp. 1398-1404 ◽  
Author(s):  
Alper Uysal ◽  
Erhan Altan
Keyword(s):  
Wear Rate ◽  
Slip Line ◽  
Field Model ◽  
Cutting Tool ◽  
Flank Wear ◽  
Cutting Speed ◽  
Chip Thickness ◽  
Rake Angle ◽  
Uncut Chip Thickness ◽  
Line Field

In this study, the slip-line field model developed for orthogonal machining with a worn cutting tool was experimentally investigated. Minimum and maximum values of five slip-line angles ( θ1, θ2, δ2, η and ψ) were calculated. The friction forces that were caused by flank wear land, chip up-curl radii and chip thicknesses were calculated by solving the model. It was specified that the friction force increased with increase in flank wear rate and uncut chip thickness and it decreased a little with increase in cutting speed and rake angle. The chip up-curl radius increased with increase in flank wear rate and it decreased with increase in uncut chip thickness. The chip thickness increased with increase in flank wear rate and uncut chip thickness. Besides, the chip thickness increased with increase in rake angle and it decreased with increase in cutting speed.

Machinability Evaluation of Inclined Planetary Motion Milling System for Difficult-to-Cut Materials

2015 ◽  
Vol 656-657 ◽  
pp. 320-327 ◽  
Author(s):  
Hidetake Tanaka ◽  
Toma Yoshita
Keyword(s):  
Cutting Tool ◽  
Rotation Axis ◽  
Tool Geometry ◽  
Planetary Motion ◽  
Orbital Drilling ◽  
Drilling Technique ◽  
Cutting Model ◽  
Cutting Experiments ◽  
Tool Rotation ◽  
The Revolution

CFRP and Titanium alloy, which are known as difficult-to-cut materials have been widely used as structural material in aviation industries. The orbital drilling is one of an effective drilling technique for the industries. However this technique has some disadvantages such as increase of cutting force due to cutting with tool center point, inertial vibration generated by revolution and high installation cost. In order to improve the disadvantages, we have invented a new drilling technique which is called inclined planetary motion milling. The inclined planetary motion milling and the planetary mechanism drilling has two axes of cutting tool rotation axis and revolution axis. Cutting tool rotation axis of the orbital drilling is moved parallel to the revolution axis in eccentric. On the other hand, in the case of the inclined planetary motion milling, eccentric of the cutting tool rotation axis is realized by inclination of a few degrees from the revolution axis. Therefore, the movement of eccentric mechanism can be reduced by comparison with the orbital drilling because inclined angle is smaller than eccentricity of the cutting tool tip. As a result, eccentric mechanism can be downsized and inertial vibration is reduced. In the study, a geometrical cutting model of inclined planetary motion milling was set up. The theoretical surface roughness of the inside of drilled holes by use of two types cutting tool geometry were calculated based on the model. And cutting experiments using the new prototype for CFRP were carried out in order to evaluate the effect on machinability with change of cutting point atmosphere. In addition, optimal cutting condition was derived according to cutting experiments for titanium alloys utilizing the orthogonal array.

Novel analysis for nanoindentation size effect using strain gradient plasticity

2005 ◽  
Vol 53 (10) ◽  
pp. 1135-1139 ◽  
Author(s):  
Hunkee Lee ◽  
Seonghyun Ko ◽  
Junsoo Han ◽  
Hyunchul Park ◽  
Woonbong Hwang
Keyword(s):  
Size Effect ◽  
Strain Gradient ◽  
Strain Gradient Plasticity ◽  
Gradient Plasticity

Optimization of Multi-Pass Pocket Milling Parameter Using Ant Colony Optimization

2014 ◽  
Vol 1043 ◽  
pp. 65-70
Author(s):  
Mohd Fadzil Faisae Ab Rashid ◽  
W.S.W. Harun ◽  
S.A.C. Ghani ◽  
N.M.Z. Nik Mohamed ◽  
A.N. Mohd Rose
Keyword(s):  
Ant Colony Optimization ◽  
Process Improvement ◽  
Material Removal ◽  
Cutting Tool ◽  
Ant Colony ◽  
Depth Of Cut ◽  
Machining Time ◽  
Pocket Milling ◽  
Independent Variables ◽  
New Material

In material removal process, milling is one of the oldest processes that were introduced to remove unwanted material using rotated cutting tool. Although a lot of research to improve the process has been done, the process improvement is not stopping there because of evolving new material, method and technology. This paper presents a study to optimize multi-pass pocket milling parameter using Ant Colony Optimization (ACO). Two objectives were set in this work; obtaining optimum surface roughness value (Ra), and minimize machining time (Tm), while the independent variables were spindle speed, feedrate and depth of cut. The numerical experiment confirm that the ACO is having better performance compare with other algorithms (including Genetic Algorithm) for this particular problem. Moreover, result from ACO algorithm able to meet required machining specification.

Effect of Minimum Quantity Lubrication to Prediction of Cutting Temperature Distribution in Turning Material AISI-1045

2020 ◽  
Vol 902 ◽  
pp. 97-102
Author(s):  
Tran Trong Quyet ◽  
Pham Tuan Nghia ◽  
Nguyen Thanh Toan ◽  
Tran Duc Trong ◽  
Luong Hong Sam ◽  
...  
Keyword(s):  
Temperature Distribution ◽  
Shear Zone ◽  
Orthogonal Cutting ◽  
Cutting Temperature ◽  
Chip Thickness ◽  
Minimum Quantity Lubrication ◽  
Minimum Quantity ◽  
The Difference ◽  
Secondary Shear Zone ◽  
Cutting Model

This paper presents a prediction of cutting temperature in turning process, using a continuous cutting model of Johnson-Cook (J-C). An method to predict the temperature distribution in orthogonal cutting is based on the constituent model of various material and the mechanics of their cutting process. In this method, the average temperature at the primary shear zone (PSZ) and the secondary shear zone (SSZ) were determined for various materials, based on a constitutive model and a chip-formation model using measurements of cutting force and chip thicknes. The J-C model constants were taken from Hopkinson pressure bar tests. Cutting conditions, cutting forces and chip thickness were used to predict shear stress. Experimental cutting heat results with the same cutting parameters using the minimum lubrication method (MQL) were recorded through the Testo-871 thermal camera. The thermal distribution results between the two methods has a difference in value, as well as distribution. From the difference, we have analyzed some of the causes, finding the effect of the minimum quantity lubrication parameters on the difference.

Size Effects in Cutting With a Diamond-Coated Tool

2011 ◽  
Author(s):  
Feng Qin ◽  
Xibing Gong ◽  
Kevin Chou
Keyword(s):  
Residual Stresses ◽  
Size Effect ◽  
Normal Stress ◽  
High Speed ◽  
Chip Thickness ◽  
Tool Geometry ◽  
Uncut Chip Thickness ◽  
Edge Radius ◽  
Coated Tool ◽  
Tool Stresses

In machining using a diamond-coated tool, the tool geometry and process parameters have compound effects on the thermal and mechanical states in the tools. For example, decreasing the edge radius tends to increase deposition-induced residual stresses at the tool edge interface. Moreover, changing the uncut chip thickness to a small-value range, comparable or smaller than the edge radius, will involve the so-called size effect. In this study, a developed 2D cutting simulation that incorporates deposition residual stresses was applied to evaluate the size effect, at different cutting speeds, on the tool stresses, tool temperatures, specific cutting energy as well as the interface stresses around a cutting edge. The size effect on the radial normal stress is more noticeable at a low speed. In particular, a large uncut chip thickness has a substantially lower stress. On the other hand, the size effect on the circumferential normal stress is more noticeable at a high speed. At a small uncut chip thickness, the stress is largely compressive.

Coupled Interfacial Energy and Temperature Effects on Size-Dependent Yield Strength and Strain Hardening of Small Metallic Volumes

2010 ◽  
Vol 133 (1) ◽  
Author(s):  
Rashid K. Abu Al-Rub ◽  
Abu N. M. Faruk
Keyword(s):  
Yield Strength ◽  
Size Effect ◽  
Strain Hardening ◽  
Interfacial Energy ◽  
Thermal Loading ◽  
Temperature Sensitive ◽  
Gradient Plasticity ◽  
Energy Effect ◽  
Size Dependent ◽  
Film Substrate

Plasticity in heterogeneous metallic materials with small volumes is governed by the interactions of dislocations at interfaces. In particular, interfaces of a material confined in a small volume can strongly affect the mechanical properties of micro and nanosystems. In this paper, the framework of higher-order strain gradient plasticity theory with interfacial energy effect is used to investigate the coupling of interfacial energy with temperature and how it affects the initial yield strength (i.e., onset of plasticity) and the strain hardening rates of confined small metallic volumes. It is postulated that the interfacial energy decreases as temperature increases such that size effect decreases as temperature increases. As an application, the size effect of thermal loading of a film-substrate system is investigated. It is shown that the temperature at which the film starts to yield plastically is size-dependent, which is attributed to the size-dependent yield strength. Furthermore, the flow stress is more temperature sensitive as the size decreases.

Sign in / Sign up

Export Citation Format

Share Document