FINITE ELEMENT CHIP FORMATION ANALYSIS FOR HIGH SPEED MILLING OPERATIONS

2008 ◽  
Vol 32 (3-4) ◽  
pp. 513-522
Author(s):  
Usama Umer ◽  
Lijing Xie ◽  
Xibin Wang

High speed end milling of hardened steel offers several advantages over EDM in die/molds applications especially due to recent development in machine tools, spindles and controllers. However successful implementation of this technology is limited mainly due to faster tool wear and undesirable surface properties. Finite element modeling and simulation techniques are capable of optimizing the cutting conditions and tool geometry by predicting the temperature and stresses distributions. In this study a finite element model has been developed to predict cutting forces, temperature and stresses distributions in flat end milling processes of hardened steel using PCBN at high cutting speeds. High speed end milling experiments were conducted using flat bottom end mills with single insert having straight cutting edge. Comparison of simulated and experimental cutting forces data shows reasonable agreement at high speed regime using the developed model.

2000 ◽  
Vol 124 (1) ◽  
pp. 32-41 ◽  
Author(s):  
D. Arola ◽  
M. B. Sultan ◽  
M. Ramulu

A finite element model was developed to simulate chip formation in the edge trimming of unidirectional Fiber Reinforced Plastics (FRPs) with orthogonal cutting tools. Fiber orientations (θ) within the range of 0 deg⩽θ⩽90 deg were considered and the cutting tool was modeled as both a rigid and deformable body in independent simulations. The principal and thrust force history resulting from numerical simulations for orthogonal cutting were compared to those obtained from edge trimming of unidirectional Graphite/Epoxy (Gr/Ep) using polycrystalline diamond tools. It was found that principal cutting forces obtained from the finite element model with both rigid and deformable body tools compared well with experimental results. Although the cutting forces increased with increasing fiber orientation, the tool rake angle had limited influence on cutting forces for all orientations other than θ=0 deg and 90 deg. However, the tool geometry did affect the degree of subsurface damage resulting from interlaminar shear failure as well as the cutting tool stress distribution. The finite element model for chip formation provides a means for optimizing tool geometry over the total range in fiber orientations in terms of the cutting forces, degree of subsurface trimming damage, and the cutting tool stresses.


Author(s):  
Xiangqin Zhang ◽  
Xueping Zhang ◽  
A. K. Srivastava

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.


2012 ◽  
Vol 576 ◽  
pp. 60-63 ◽  
Author(s):  
N.A.H. Jasni ◽  
Mohd Amri Lajis

Hard milling of hardened steel has wide application in mould and die industries. However, milling induced surface finish has received little attention. An experimental investigation is conducted to comprehensively characterize the surface roughness of AISI D2 hardened steel (58-62 HRC) in end milling operation using TiAlN/AlCrN multilayer coated carbide. Surface roughness (Ra) was examined at different cutting speed (v) and radial depth of cut (dr) while the measurement was taken in feed speed, Vf and cutting speed, Vc directions. The experimental results show that the milled surface is anisotropic in nature. Surface roughness values in feed speed direction do not appear to correspond to any definite pattern in relation to cutting speed, while it increases with radial depth-of-cut within the range 0.13-0.24 µm. In cutting speed direction, surface roughness value decreases in the high speed range, while it increases in the high radial depth of cut. Radial depth of cut is the most influencing parameter in surface roughness followed by cutting speed.


2011 ◽  
Vol 70 ◽  
pp. 315-320 ◽  
Author(s):  
Riaz Muhammad ◽  
Agostino Maurotto ◽  
Anish Roy ◽  
Vadim V. Silberschmidt

Analysis of the cutting process in machining of advanced alloys, which are typically difficult-to-machine materials, is a challenge that needs to be addressed. In a machining operation, cutting forces causes severe deformations in the proximity of the cutting edge, producing high stresses, strain, strain-rates and temperatures in the workpiece that ultimately affect the quality of the machined surface. In the present work, cutting forces generated in a vibro-impact and hot vibro-impact machining process of Ti-based alloy, using an in-house Ultrasonically Assisted Turning (UAT) setup, are studied. A three-dimensional, thermo-mechanically coupled, finite element model was developed to study the thermal and mechanical processes in the cutting zone for the various machining processes. Several advantages of ultrasonically assisted turning and hot ultrasonically assisted turning are demonstrated when compared to conventional turning.


2011 ◽  
Vol 399-401 ◽  
pp. 1806-1811
Author(s):  
Yong Hong Chen ◽  
Peng Chen ◽  
Ai Qin Tian

The finite element model of the roof of aluminum high-speed train was established, double ellipsoid heat source was employed, and heat elastic-plastic theory was used to simulate welding residual stress of the component under different welding sequence based on the finite element analysis software SYSWELD. The distribution law of welding residual stress was obtained. And the effects of the welding sequence on the value and distribution of residual stress was analyzed. The numerical results showed that the simulation data agree well with experimental test data. The maximum residual stress appears in the weld seam and nearby. The residual stress value decreases far away from the welding center. Welding sequence has a significant impact on the final welding residual stress when welding the roof of aluminum body. The side whose residual stress needs to be controlled should be welded first.


Author(s):  
John A. Malluck ◽  
Shreyes N. Melkote

This paper presents a theoretical model for predicting the elastic deformations of ring-type workpieces due to in-plane chucking and cutting forces applied in turning processes. The model is derived from classical elasticity theory for bending of thin rings. Experimental results are presented to verify the strengths and limitations of this model. The results from a finite element model are also presented for comparison. For the ring diameters and radial chucking loads considered in this work, it is shown that the theoretical model is accurate to within 11% of the measured radial deformations for rings with inner-to-outer diameter ratio (Din/Dout) of 0.881. The finite element model is shown to yield slightly better results. The applicability of the theoretical model is illustrated by using it to predict the surface error produced in turning of a ring.


Sign in / Sign up

Export Citation Format

Share Document