Experimental and numerical study of chip formation during straight turning of hardened AISI 4340 steel

Belhadi, Salim; Mabrouki, Tarek; Rigal, Jean-François; Boulanouar, Lakhdar

doi:10.1243/095440505x32445

Cited by 60 publications

(44 citation statements)

References 15 publications

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“…In comparison with video capture (figure 4-e), that may induce the chip fragmentation. As shown by previous published papers [1], the segmentation is the result of a softening state during tool/workpiece interaction, but it can be favoured by other phenomena like pre-existing micro-cracks, machine tool vibrations or chip self-contact during its curl-up as explained previously. We can noticed that chip breaker have an important role in chip curvature, and consequently in segmentation and fragmentation.…”

Section: Resultsmentioning

confidence: 58%

“…Supposing incompressible material [1], segmentation and fragmentation frequencies were calculated starting from number of saw-teeth, chip thickness, chip length, feed rate and cutting speed. Secondly, video sequences were performed.…”

Section: Analysis Methodologymentioning

confidence: 99%

“…Quadrilateral continuum elements were used for a coupled temperaturedisplacement calculation. Interactions between contacting bodies are defined with a Coulomb's friction law [1,4]. To optimize the management of the contact between chip and cutting tool, a four-part model was developed ( figure 3).…”

Section: Geometrical Model and Hypothesismentioning

confidence: 99%

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Dry cutting study of an aluminium alloy (A2024-T351): a numerical and experimental approach

et al. 2008

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In the present contribution, experimental and numerical methodologies concerning orthogonal cutting are proposed in order to study the dry cutting of an aeronautic aluminium alloy (A2024-T351). The global aim concerns the comprehension of physical phenomena accompanying chip formation with respect to cutting speed, such as chip segmentation and fragmentation. For experimental validation, series of tests are carried out concerning geometrical analysis of the chip; video sequences of chip formation with a high-speed camera, and high-frequency sampling measurements of the cutting force signal are realised. For the numerical approach, the material and its ductile shear failure behaviour are based on the Johnson-Cook laws. The material failure model exploited considers both damage evolution and energy coupling. Numerical results concerning cutting force and segmentation frequency are compared to experimental ones. Moreover ,an analysis of damage distributions is presented.

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Section: Resultsmentioning

confidence: 58%

Section: Analysis Methodologymentioning

confidence: 99%

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Dry cutting study of an aluminium alloy (A2024-T351): a numerical and experimental approach

et al. 2008

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“…Thus, the temperature rise in the chip can be estimated with the adiabatic heating condition. The temperature increase is calculated directly at the material integration points according to the adiabatic thermal energy increases caused by inelastic deformation [13], [16] and [30]. Heat conduction has not a contribution in an adiabatic analysis.…”

Section: Temperature Rise Due To Adiabatic Processmentioning

confidence: 99%

Chip Formation Mechanism Using Finite Element Simulation

Öpöz¹,

Chen²

2016

SV-JME

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Opoz, TT and Chen, X Chip formation mechanism using finite element simulation http://researchonline.ljmu.ac.uk/4059/ Article LJMU has developed LJMU Research Online for users to access the research output of the University more effectively. Copyright © and Moral Rights for the papers on this site are retained by the individual authors and/or other copyright owners. Users may download and/or print one copy of any article(s) in LJMU Research Online to facilitate their private study or for non-commercial research. You may not engage in further distribution of the material or use it for any profit-making activities or any commercial gain.The version presented here may differ from the published version or from the version of the record. Please see the repository URL above for details on accessing the published version and note that access may require a subscription. INTRODUCTIONChip formation during machining processes is a material removal process in which the materials are removed from the workpiece in the form of numerous tiny chips. To understand chip formation regarding the chip types, shapes as well as the stress/strain distribution would help the prediction of cutting force and thermal behaviour to avoid unexpected vibration and thermal damage. To do this, the finite element models of machining processes are very popular for simulating chip formation [1] to [15]. The reason is to minimize labour cost and save time by reducing expensive experimental tests. In contrast, the estimation of some physical phenomena such as the distribution of stress and strain under machining conditions is quite difficult to accomplish with experimental tests. Finite element method (FEM) provides a convenient method to visualise material performance under different machining conditions. Therefore, the prediction of chip types and chip shapes under different operating conditions is one of the significant benefits provided by FEM simulations. In metal cutting processes, often three types of chip formation occur (continuous chips, serrated chips, and discontinuous chips), which are produced as a result of the cutting deformation mechanism, operating parameters, and workpiece mechanical and thermal properties. The continuous chip is often considered to be an ideal chip that generates stable cutting forces; however, it is not desired for automated machining because the continuous chips may obstruct the machining process, which may lead to unpredictable damage on the machined surface, cutting tool or machine tool. To minimize these problems, serrated chips that are easier to break and remove are preferred during machining [1] and [2], so, predicting the cutting conditions which lead to a serrated chip has become increasingly important.In some literature, serrated chips are called sawtooth shape or continuous segmented chips. Increased segmentation on continuous chips eventually leads to serrated chips. It is common knowledge that segmentation during chip formation is triggered by two phenomena: the formation of the adiabatic shear band a...

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“…The geometric characteristics of serrated chips are described by the two parameters of serrated degree G s and serrated frequency f, which are expressed by Eqs. (6) [40] and (7) [41], respectively. The serrated chip can be regarded as a sequence of trapezoids arranged periodically, and each trapezoid is formed by two shearing planes.…”

Section: Geometric Characteristics Of Serrated Chipsmentioning

confidence: 99%

Investigations on the chip formation mechanism and shear localization sensitivity of high-speed machining Ti6Al4V

Wang

2014

Int J Adv Manuf Technol

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This study develops a combined numerical and experimental approach to get deeper insights into chip formation mechanism for high-speed machining of titanium alloy Ti6Al4V. The numerical investigation of high-speed machining is implemented with the aid of finite element analysis software Abaqus/Explicit, in which the Johnson-Cook (JC) fracture model with an energy-based ductile failure criterion is adopted. Meanwhile, the experiments of high-speed orthogonal cutting are carried out to validate the numerical results. The cutting speeds are selected ranging from 50 to 3,000 m/ min, and the uncut chip thickness is fixed at 0.1 mm. The variables investigated include the serrated degree and serrated frequency of chips in addition to the cutting force. The results show that both the serrated degree and serrated frequency have positive correlations with the cutting speed. An important regularity for the transformation of chip morphology from serrated to unit at a critical cutting speed has been achieved, and the critical value for Ti6Al4V is about 2,500 m/min. The research also finds that the cutting force decreases with the increasing cutting speed, while its fluctuant frequency and amplitude increase sharply. Furthermore, the influences of JC fracture constants (the five constants in JC fracture model) on chip formation are investigated based on the finite element method, which is the main original and innovative highlight of this study. The shear localization sensitivity is firstly proposed to describe the influences of JC fracture constants on the chip formation process. When the JC fracture constants decrease, the shear localization sensitivity is positive which means that the serrated degree increases and vice versa. The sensitivity analyses indicate that the influences of initial failure strain D 1 and exponential factor of stress triaxiality D 2 on chip formation process are more conspicuous than the rest three ones. This paper is enticing from both the engineering and the analytical perspectives aimed at predicting the evolution of serrated chip formation and chip morphology transformation in metal cutting process. Keywords Finite element method . JC fracture model . Shear localization sensitivity . High-speed machining . Ti6Al4V Nomenclature A Initial yield stress (MPa) a c Uncut chip thickness (mm) B Hardening modulus (MPa) C Strain rate dependency coefficient d Pitch of two neighboring trapezoids in serrated chips (mm) D Damage variable d 1 Diameter of slot milling cutter (mm) d 2 Width of workpiece (mm) D 1 Initial failure strain of JC fracture model D 2Exponential factor of JC fracture model D 3Triaxiality factor of JC fracture model D 4Strain rate factor of JC fracture model D 5Temperature factor of JC fracture model fChip serrated frequency

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Experimental and numerical study of chip formation during straight turning of hardened AISI 4340 steel

Cited by 60 publications

References 15 publications

Dry cutting study of an aluminium alloy (A2024-T351): a numerical and experimental approach

Dry cutting study of an aluminium alloy (A2024-T351): a numerical and experimental approach

Chip Formation Mechanism Using Finite Element Simulation

Investigations on the chip formation mechanism and shear localization sensitivity of high-speed machining Ti6Al4V

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