Cutting forces prediction: The experimental identification of orthogonal cutting coefficients

Titanium and its alloys are difficult to machine due to their high chemical reactivity with tool materials and low thermal conductivity. Chip segmentation caused by the thermoplastic instability is always observed in titanium machining processes, which leads to varied cutting forces and chip thickness, etc. This paper presents an analytical modelling approach for cutting forces in near-orthogonal cutting of titanium alloy Ti6Al4V. The catastrophic shear instability in the primary shear plane is assumed as a semi-static process. An analytical approach is used to evaluate chip thicknesses and forces in the near-orthogonal cutting process. The shear flow stress of the material is modelled by using the Johnson–Cook constitutive material law where the strain hardening, strain rate sensitivity and thermal softening behaviours are coupled. The thermal equations with non-uniform heat partitions along the tool–chip interface are solved by a finite difference method. The model prediction is verified with experimental data, where a good agreement in terms of the average cutting forces and chip thickness is shown. A comparison of the predicted temperatures with published data obtained by using the finite element method is also presented.

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Analytical cutting force modelling of micro-slot grinding considering tool-workpiece interactions on both primary and secondary tool surfaces

Journal of Manufacturing Science and Engineering ◽

10.1115/1.4051235 ◽

2021 ◽

pp. 1-43

Author(s):

Ashwani Pratap ◽

Karali Patra

Keyword(s):

Cutting Force ◽

Cutting Forces ◽

Orthogonal Cutting ◽

Surface Interactions ◽

Surface Interaction ◽

Edge Density ◽

Force Model ◽

Height Distribution ◽

Force Modeling ◽

Tool Surface

Abstract This work presents an analytical cutting force modeling for micro-slot grinding. Contribution of the work lies in the consideration of both primary and secondary tool surface interactions with the work surface as compared to the previous works where only primary tool surface interaction was considered during cutting force modeling. Tool secondary surface interaction with workpiece is divided into two parts: cutting/ ploughing by abrasive grits present in exterior margin of the secondary tool surface and sliding/adhesion by abrasive grits in the inner margins of the secondary tool surface. Orthogonal cutting force model and indentation based fracture model is considered for cutting by both the abrasives of primary tool surface and the abrasives of exterior margin on the secondary surface. Asperity level sliding and adhesion model is adopted to solve the interaction between the workpiece and the interior margin abrasives of secondary tool surface. Experimental measurement of polycrystalline diamond tool surface topography is carried out and surface data is processed with image processing tools to determine the tool surface statistics viz., cutting edge density, grit height distribution and abrasive grit geometrical measures. Micro-slot grinding experiments are carried out on BK7 glass at varying feed rate and axial depths of cut to validate the simulated cutting forces. Simulated cutting forces considering both primary and secondary tool surface interactions are found to be much closer to the experimental cutting forces as compared to the simulated cutting forces considering only primary tool surface interaction.

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Specific Cutting Forces of Isotropic and Orthotropic Engineered Wood Products by Round Shape Machining

Materials ◽

10.3390/ma11122575 ◽

2018 ◽

Vol 11 (12) ◽

pp. 2575 ◽

Cited By ~ 1

Author(s):

Giacomo Goli ◽

Rémi Curti ◽

Bertrand Marcon ◽

Antonio Scippa ◽

Gianni Campatelli ◽

...

Keyword(s):

Cutting Forces ◽

Medium Density Fiberboard ◽

Laminate Veneer Lumber ◽

Scientific Basis ◽

Wood Products ◽

Orthotropic Materials ◽

Machining Parameters ◽

Cutting Coefficients ◽

Round Shape ◽

Different Depths

The set-up of machining parameters for non-ferric materials such as wood and wood-based materials is not yet defined on a scientific basis. In this paper, a new rapid experimental method to assess the specific cutting coefficients when routing isotropic and orthotropic wood-based materials is presented. The method consists of routing, with different depths of cut, a given material previously machined to a round shape after having it fixed on a dynamometric platform able to measure the cutting forces. The execution of subsequent cuts using different depths of cut allows the calculation of the specific cutting coefficients. With the measurement being done during real routing operations, a method to remove machine vibrations was also developed. The specific cutting coefficients were computed for the whole set of grain orientations for orthotropic materials and as an average for isotropic ones. The aim of this paper is to present and validate the whole method by machining selected materials such as Polytetrafluoroethylene—PTFE (isotropic), Medium Density Fiberboard—MDF (isotropic), beech Laminate Veneer Lumber—LVL (orthotropic) and poplar LVL (orthotropic). The method and the proposed analysis have been shown to work very effectively and could be used for optimization and comparison between materials and processes.

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Virtual Five-Axis Flank Milling of Jet Engine Impellers: Part 1 — Mechanics of Five-Axis Flank Milling

Volume 3: Design and Manufacturing ◽

10.1115/imece2007-41351 ◽

2007 ◽

Cited By ~ 5

Author(s):

W. Ferry ◽

Y. Altintas

Keyword(s):

Cutting Force ◽

Cutting Forces ◽

Orthogonal Cutting ◽

Chip Thickness ◽

Friction Angle ◽

Flank Milling ◽

Cutting Force Prediction ◽

Jet Engine ◽

End Mills ◽

Five Axis

Jet engine impeller blades are flank-milled with tapered, helical, ball-end mills on five-axis machining centers. The impellers are made from difficult-to-cut titanium or nickel alloys, and the blades must be machined within tight tolerances. As a consequence, deflections of the tool and flexible workpiece can jeopardize the precision of the impellers during milling. This work is the first of a two part paper on cutting force prediction and feed optimization for the five-axis flank milling of an impeller. In Part I, a mathematical model for predicting cutting forces is presented for five-axis machining with tapered, helical, ball-end mills with variable pitch and serrated flutes. The cutter is divided axially into a number of differential elements, each with its own feed coordinate system due to five-axis motion. At each element, the total velocity due to translation and rotation is split into horizontal and vertical feed components, which are used to calculate total chip thickness along the cutting edge. The cutting forces for each element are calculated by transforming friction angle, shear stress and shear angle from an orthogonal cutting database to the oblique cutting plane. The distributed cutting load is digitally summed to obtain the total forces acting on the cutter and blade. The model can be used for general five-axis flank milling processes, and supports a variety of cutting tools. Predicted cutting force measurements are shown to be in reasonable agreement with those collected during a roughing operation on a prototype integrally bladed rotor (IBR).

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A Study on the Influence of Laser Parameters on Laser-Assisted Machining of AISI H-13 Steel

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.827.92 ◽

2019 ◽

Vol 827 ◽

pp. 92-97 ◽

Cited By ~ 1

Author(s):

Evaggelos Kaselouris ◽

A. Baroutsos ◽

T. Papadoulis ◽

Nektarios A. Papadogiannis ◽

Michael Tatarakis ◽

...

Keyword(s):

Laser Beam ◽

Cutting Forces ◽

Local Heating ◽

Orthogonal Cutting ◽

Material Model ◽

Beam Diameter ◽

Laser Parameters ◽

Laser Assisted Machining ◽

Von Mises ◽

Cutting Processes

The machinability of a steel workpiece through conventional and Laser-Assisted Machining (LAM) is studied by the help of the Finite Element Method (FEM). In LAM, the laser beam is applied as a heat source to ensure sufficient local heating of the workpiece at a certain distance from the cutting tool and the machinability of materials is increased since the values of the cutting forces are decreased. A thermostructural FEM model is developed to simulate the conventional and the LAM orthogonal cutting of AISI H-13 steel. The Johnson-Cook material model that takes into account the effect of plastic strain, strain rate and temperature, along with a fracture model, is used in the simulations. For varying feed rate, parametric simulations are carried out, for different test cases of the laser beam diameter and the laser heat flux. Key engineering parameters, like cutting forces, temperature distributions, Von Mises stresses and plastic strains, are compared for both cutting processes. This comparison leads to important notifications on the influence of the cutting and laser parameters to LAM. The obtained results indicate that LAM may improve the machinability of AISI H-13 steel by reducing the cutting forces to a maximum percentage of ~15%.

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Mechanics and Dynamics of Hard Turning Process

Manufacturing Engineering and Materials Handling Engineering ◽

10.1115/imece2004-61067 ◽

2004 ◽

Cited By ~ 2

Author(s):

Kivilcim Buyukhatipoglu ◽

Ismail Lazoglu ◽

Hubert Kratz ◽

Fritz Klocke

Keyword(s):

Cutting Forces ◽

Hard Turning ◽

Prediction Models ◽

Orthogonal Cutting ◽

Cutting Tools ◽

Temperature Fields ◽

Turning Process ◽

Cycle Times ◽

High Productivity ◽

Recent Developments

In precision machining, due to the recent developments on the cutting tools, machine tool structural rigidity and improved CNC controllers, hard turning is an emerging process as an alternative to some of the grinding processes by providing reductions in costs and cycle-times. In industrial environments, hard turning is established for geometry features of parts with low to medium requirements on part quality. Better and deeper understanding of cutting forces, stresses and temperature fields, temperature gradients created during the machining are very critical for achieving highest quality products and high productivity in feasible cycle times. In order to enlarge the capability profile of the hard turning process, this paper introduces to prediction models of mechanical and thermal loads during turning of 51CrV4 with hardness of 68 HRC by CBN tool. The shear flow stress, shear and friction angles are determined from the orthogonal cutting tests. Cutting force coefficients are determined from orthogonal to oblique transformations. Cutting forces and surface profiles are predicted and compared with experimental measurements.

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Prediction of the hobbing cutting forces from a thermomechanical modeling of orthogonal cutting operation

Journal of Manufacturing Processes ◽

10.1016/j.jmapro.2016.05.002 ◽

2016 ◽

Vol 23 ◽

pp. 1-12 ◽

Cited By ~ 4

Author(s):

Naoual Sabkhi ◽

Abdelhadi Moufki ◽

Mohammed Nouari ◽

Cyril Pelaingre ◽

Claude Barlier

Keyword(s):

Cutting Forces ◽

Orthogonal Cutting ◽

Cutting Operation ◽

Thermomechanical Modeling

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Influence of Reground Tool Sharpness on Micro-Cutting Process

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.37-38.550 ◽

2010 ◽

Vol 37-38 ◽

pp. 550-553

Author(s):

Xin Li Tian ◽

Zhao Li ◽

Xiu Jian Tang ◽

Fang Guo ◽

Ai Bing Yu

Keyword(s):

Cutting Forces ◽

Orthogonal Cutting ◽

Cutting Tools ◽

Chip Thickness ◽

Cutting Edge ◽

Cutting Process ◽

Micro Cutting ◽

Temperature Distributions ◽

Edge Radius ◽

1045 Steel

Tool edge radius has obvious influences on micro-cutting process. It considers the ratio of the cutting edge radius and the uncut chip thickness as the relative tool sharpness (RST). FEM simulations of orthogonal cutting processes were studied with dynamics explicit ALE method. AISI 1045 steel was chosen for workpiece, and cemented carbide was chosen for cutting tool. Sixteen cutting edges with different RTS values were chosen for analysis. Cutting forces and temperature distributions were calculated for carbide cutting tools with these RTS values. Cutting edge with a small RTS obtains large cutting forces. Ploughing force tend to sharply increase when the RTS of the cutting edge is small. Cutting edge with a reasonable RTS reduces the heat generation and presents reasonable temperature distributions, which is beneficial to cutting life. The force and temperature distributions demonstrate that there is a reasonable RTS range for the cutting edge.

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FEM Analysis of Residual Stress Distribution and Cutting Forces in Orthogonal Cutting with Different Initial Stresses

Materials Science Forum ◽

10.4028/www.scientific.net/msf.800-801.380 ◽

2014 ◽

Vol 800-801 ◽

pp. 380-384 ◽

Cited By ~ 3

Author(s):

Yuan Ma ◽

Ding Wen Yu ◽

Ping Fa Feng

Keyword(s):

Residual Stress ◽

Stress Distribution ◽

Compressive Stress ◽

Cutting Forces ◽

High Speed ◽

Orthogonal Cutting ◽

Fem Simulation ◽

Fem Analysis ◽

Cutting Parameters ◽

Initial Stresses

Machining induced residual stress is influenced by many factors. Extensive studies on the influence of cutting parameters, tool parameters, as well as basic properties of materials have been carried out during the past decades, while another important factor, initial stress distribution in workpiece, was often ignored. In this paper a relatively complete FEM simulation on the formation mechanism of machining induced residual stress in high speed machining is carried out, illustrating the three stress zones affected by mechanical and thermal loads, and their influence on ultimate residual stress. And the influence of initial compressive stress on stress formation and cutting forces is analyzed. Initial compressive stress weakens the tensile effect caused by the shear deformation, and the residual stress tend to be more compressive with larger initial compressive stress. Cutting force becomes larger with the increase of initial compressive stress. And the results in this FEM study can be used to explain some unaccounted experimental phenomena in former researches.

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