Prediction of Cutting Forces in High Speed Machining of Ti6Al4V Using SPH Method

2015 ◽  
Author(s):  
Alaa A. Olleak ◽  
Hassan A. El-Hofy
Keyword(s):  
Cutting Forces ◽  
High Speed ◽  
Orthogonal Cutting ◽  
Chip Morphology ◽  
3D Models ◽  
Material Behavior ◽  
Coupled Analysis ◽  
High Speed Machining ◽  
Machining Processes ◽  
Sph Method

Over the last few decades, the interest in modeling of machining processes has been growing. In this regard, the smoothed particle hydrodynamics (SPH) method is one of the latest powerful techniques used for that purpose. The strength of SPH lies behind its accuracy in stress calculations and the ability to handle situations involving large amount of deformation, which is difficult to be tackled using traditional finite element methods. This work aims to present and evaluate the use of SPH method in modeling of high speed machining (HSM). A thermo-mechanical coupled analysis of both 2D and 3D models is performed using LS-DYNA. The simulation aims to predict the cutting forces and chip morphology during high speed orthogonal cutting of Ti6Al4V alloy. In order to accurately simulate the material behavior during cutting, Johnson-Cook material constitutive model is used. The results from SPH model are validated using published experimental data.

Finite Element Simulation of Extremely High Speed Machining of Ti6Al4V Alloy

2011 ◽  
Vol 141 ◽  
pp. 293-297 ◽  
Author(s):  
Yang Tan ◽  
Yi Lin Chi ◽  
Ya Yu Huang ◽  
Ting Qiang Yao
Keyword(s):  
Finite Element ◽  
High Speed ◽  
Void Nucleation ◽  
Chip Morphology ◽  
Ti6al4v Alloy ◽  
Material Behavior ◽  
Fracture Mechanisms ◽  
High Speed Machining ◽  
Damage Initiation ◽  
Damage And Fracture

The finite element modeling and simulation of extremely high speed machining of Ti6Al4V alloy are presented in the paper. The Johnson-Cook’s constitutive model is used to describe the material behavior. The Johnson-Cook damage initiation criterion is used to predict the onset of damage due to void nucleation in ductile fracture. A damage evaluation law based on plastic strain energy and a fracture criterion combining the effect of different fracture mechanisms are proposed to model the progressive damage and fracture, respectively. Simulation results show that the predicted chip morphology agrees well with the experimental one. The distribution of temperature and specific cutting force are discussed later.

Numerical Simulation of High Speed Machining of Alloy Cast Iron

2012 ◽  
Vol 468-471 ◽  
pp. 2310-2314
Author(s):  
Yang Tan ◽  
Yi Lin Chi ◽  
Ya Yu Huang ◽  
Ting Qiang Yao
Keyword(s):  
Cast Iron ◽  
High Speed ◽  
Cutting Speed ◽  
Chip Morphology ◽  
Element Model ◽  
Material Behavior ◽  
High Speed Machining ◽  
Alloy Steels ◽  
Alloy Cast Iron ◽  
Alloy Cast

High speed milling of hard alloy steels utilized in dies and molds is a highly demanding operation. The finite element model was developed to investigate the high speed machining of alloy cast iron which is used in auto panel dies. The modified Johnson-cook constitutive model was used to model the complex dynamic material behavior, a damage evaluation law based on Cockroft and Latham model was used to simulate the ductile fracture of alloy cast iron. The crack initiation and propagation was simulated explicitly using an explicit FEM code. Simulation results showed that the chip morphology transited from continuous to saw-tooth chip with increasing cutting speed, cutting force decreased when increasing the cutting speed, which provide a useful understanding of chip formation process in high speed machining of alloy cast iron.

Experimental and FEM Study of Serrated Chip Formation in High Speed Turning Processes

2011 ◽  
Vol 264-265 ◽  
pp. 1021-1026
Author(s):  
U. Umer ◽  
Li Jing Xie ◽  
Syed Jawid Askari ◽  
S.N. Danish ◽  
S.I. Butt
Keyword(s):  
Chip Formation ◽  
Cutting Forces ◽  
High Speed ◽  
Metal Cutting ◽  
Orthogonal Cutting ◽  
Cutting Speed ◽  
Chip Morphology ◽  
Serrated Chip ◽  
High Speed Turning ◽  
Serrated Chip Formation

The finite element method (FEM) has been used to model high speed turning processes with orthogonal cutting conditions. In most of the situations, continuous chip formation is used to analyze the turning process due to its stability and allowing many conditions to simplify the process. However with the increasing applications of high speed turning, serrated chip formation is becoming a more common phenomenon in metal cutting. Serrated chips usually occur in machining of difficult to cut materials at or above a threshold speed. An updated Lagrangian formulation has been used in this study which works with element deletion technique based on a failure criterion. The Johnson Cook strain-hardening thermal-softening material model is used to model serrated chip formation. In addition high speed turning experiments were conducted on AISI H13 tubes using PCBN to analyze serrated chip phenomenon. The chips were analyzed after surface treatment using scanning electron microscope. It has been found that the length of cuts in the chip increases with the cutting speed and the chip changes from serrated to discontinuous. Different process variables like cutting forces, chip morphology, stress, strain and temperature distributions are predicted at different process parameters using FEM. The results show cyclic variation in the cutting forces at high cutting speeds due to varying chip load.

scholarly journals Modeling of Ti6Al4V Alloy Orthogonal Cutting with Smooth Particle Hydrodynamics: A Parametric Analysis on Formulation and Particle Density

Metals ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 388 ◽  
Author(s):  
Adam Lampropoulos ◽  
Angelos Markopoulos ◽  
Dimitrios Manolakos
Keyword(s):  
Cutting Forces ◽  
Parametric Analysis ◽  
Particle Density ◽  
Orthogonal Cutting ◽  
Ti6al4v Alloy ◽  
Smooth Particle Hydrodynamics ◽  
Machining Processes ◽  
Sph Method ◽  
Particle Hydrodynamics ◽  
Chip Formation Mechanism

Computational modeling is a widely used method for simulation and analysis of machining processes. Smooth particle hydrodynamics (SPH) is a comparatively recently developed method that is used for the simulation of processes where high strains and fragmentation occur. The purpose of this work is the application of the SPH method for the prediction of cutting forces and chip formation mechanism in orthogonal cutting of Ti6Al4V alloy. In addition, it is examined how the final results of the simulation are influenced by the choice of the particular formulation of the SPH method, as well as by the density of the particles.

Predicting the High Speed Cutting Process of Titanium Alloy by Finite Element Method

2011 ◽  
Author(s):  
Xiangqin Zhang ◽  
Xueping Zhang ◽  
A. K. Srivastava
Keyword(s):  
Finite Element ◽  
Cutting Forces ◽  
High Speed ◽  
Cutting Temperature ◽  
Chip Morphology ◽  
Cutting Process ◽  
Fe Model ◽  
Dry Cutting ◽  
Friction Coefficients ◽  
Machining Conditions

To predict the cutting forces and cutting temperatures accurately in high speed dry cutting Ti-6Al-4V alloy, a Finite Element (FE) model is established based on ABAQUS. The tool-chip-work friction coefficients are calculated analytically using the measured cutting forces and chip morphology parameter obtained by conducting the orthogonal (2-D) machining tests. It reveals that the friction coefficients between tool-work are 3∼7 times larger than that between tool-chip, and the friction coefficients of tool-chip-work vary with feed rates. The analysis provides a better reference for the tool-work-chip friction coefficients than that given by literature empirically regardless of machining conditions. The FE model is capable of effectively simulating the high speed dry cutting process of Ti-6Al-4V alloy based on the modified Johnson-Cook model and tool-work-chip friction coefficients obtained analytically. The FE model is further validated in terms of predicted forces and the chip morphology. The predicted cutting force, thrust force and resultant force by the FE model agree well with the experimentally measured forces. The errors in terms of the predicted average value of chip pitch and the distance between chip valley and chip peak are smaller. The FE model further predicts the cutting temperature and residual stresses during high speed dry cutting of Ti-6Al-4V alloy. The maximum tool temperatures exist along the round tool edge, and the residual stress profiles along the machined surface are hook-shaped regardless of machining conditions.

scholarly journals Analytical modelling of cutting forces in near-orthogonal cutting of titanium alloy Ti6Al4V

2014 ◽  
Vol 229 (6) ◽  
pp. 1122-1133 ◽  
Author(s):  
Yun Chen ◽  
Huaizhong Li ◽  
Jun Wang
Keyword(s):  
Titanium Alloy ◽  
Cutting Forces ◽  
Chemical Reactivity ◽  
Orthogonal Cutting ◽  
Chip Thickness ◽  
Analytical Modelling ◽  
Shear Instability ◽  
Published Data ◽  
Machining Processes ◽  
Titanium Alloy Ti6al4v

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.

FEM Simulation of the Residual Stress in the Machined Surface Layer for High-Speed Machining

2006 ◽  
Vol 315-316 ◽  
pp. 140-144 ◽  
Author(s):  
Su Yu Wang ◽  
Xing Ai ◽  
Jun Zhao ◽  
Z.J. Lv
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Surface Layer ◽  
Residual Stresses ◽  
High Speed ◽  
Metal Cutting ◽  
Orthogonal Cutting ◽  
High Speed Machining ◽  
Machined Surface ◽  
Cutting Model

An orthogonal cutting model was presented to simulate high-speed machining (HSM) process based on metal cutting theory and finite element method (FEM). The residual stresses in the machined surface layer were obtained with various cutting speeds using finite element simulation. The variations of residual stresses in the cutting direction and beneath the workpiece surface were studied. It is shown that the thermal load produced at higher cutting speed is the primary factor affecting the residual stress in the machined surface layer.

A Metallo-Thermomechanically Coupled Analysis of Orthogonal Cutting of AISI 1045 Steel

2012 ◽  
Vol 134 (5) ◽  
Author(s):  
Hongtao Ding ◽  
Yung C. Shin
Keyword(s):  
Experimental Data ◽  
Cutting Force ◽  
Orthogonal Cutting ◽  
Cutting Temperature ◽  
Chip Morphology ◽  
Machining Process ◽  
Coupled Analysis ◽  
Aisi 1045 Steel ◽  
Aisi 1045 ◽  
1045 Steel

Materials often behave in a complicated manner involving deeply coupled effects among stress/stain, temperature, and microstructure during a machining process. This paper is concerned with prediction of the phase change effect on orthogonal cutting of American Iron and Steel Institute (AISI) 1045 steel based on a true metallo-thermomechanical coupled analysis. A metallo-thermomechanical coupled material model is developed and a finite element model (FEM) is used to solve the evolution of phase constituents, cutting temperature, chip morphology, and cutting force simultaneously using abaqus. The model validity is assessed using the experimental data for orthogonal cutting of AISI 1045 steel under various conditions, with cutting speeds ranging from 198 to 879 m/min, feeds from 0.1 to 0.3 mm, and tool rake angles from −7 deg to 5 deg. A good agreement is achieved in chip formation, cutting force, and cutting temperature between the model predictions and the experimental data.

Modeling Machining at High Speeds as a Fluid Mechanics Problem

2008 ◽  
Author(s):  
Roman V. Kazban ◽  
James J. Mason
Keyword(s):  
Fluid Mechanics ◽  
Stagnation Point ◽  
Potential Flow ◽  
High Speed ◽  
Material Behavior ◽  
High Speed Machining ◽  
Flow Solution ◽  
High Speeds ◽  
Ultra High Speed ◽  
Very High

Even though many models for machining exist, most of them are for low-speed machining, where momentum is negligible and material behavior is well approximated by quasi-static plastic constitutive laws. In machining at high speeds, momentum can be important and the strain rate can be exceedingly high. For these reasons, a fluid mechanics approach to understanding high-speed, very high-speed, and ultra-high-speed machining is attempted here. Namely, a potential flow solution is used to model the behavior of the material around a sharp tool tip during machining at high speeds. It is carefully argued that the potential flow solution is relevant and can be used as a first approximation to model the behavior of a metal during high-speed, very high-speed, or ultra-high-speed machining events; and at a minimum, the potential flow solution is qualitatively useful in understanding mechanics of machining at high speeds and above. Interestingly, the flow solution predicts that there is a stagnation point on the rake face, not at the tool tip as is usually assumed. Because the stagnation point is not at the tool tip, the flow solution predicts a significant amount of deformation in the workpiece resulting in large residual strains that may lead to a temperature rise on the finished surface.

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