Local cutting forces

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Mechanical analysis of local cutting forces and transient state when drilling of heat-resistant austenitic stainless steel

Mechanical analysis of local cutting forces and transient state when drilling of heat-resistant austenitic stainless steel

underestimated by using this approach. Based on the oblique cutting tool in drilling, Ke et al. [ 7 ] have developed a model to predict the spiral and the string chip formation generated by each elementary cutting edge. Moreover, Koehler [ 8 ] has used a quick-stop device (QSD) to analyze the chip formation along the cutting edge and he divided the cutting edge into seven sections according to its cutting geometry. Then, he deter- mined the contribution of each section on the mechanical load. Following the same approach than Poutord et al. [ 9 ], the cur- rent study investigates the mechanical forces during the dril- ling process especially at its transient state. Furthermore, new experiment methods are here proposed and discussed to deter- mine the contribution of each elementary cutting edge (ECE) on the evolution of local forces as shown in Fig. 1 . This ap- proach basically describes the effect of the local cutting ge- ometry on local cutting forces and does not analyze thermal aspects since the cutting geometry influences directly the cut- ting forces more than the temperature. Nonetheless, existing local modeling strategies take into account the effect of the machining temperature especially in numerical simulation to model machining operations in elementary configurations. For example, Li et al. [ 10 ] investigate the temperature effect based on an oblique cutting configuration to develop a finite 3D element thermal model during drilling of titanium. In the same manner, Jomaa et al. [ 11 ] also include the effect of ma- chining temperature to develop a 2D finite element model predicting the cutting forces and the chip form when machin- ing aluminum alloy.
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Cutting Forces Modeling in Finish Turning of Inconel 718 Alloy with Round Inserts

Cutting Forces Modeling in Finish Turning of Inconel 718 Alloy with Round Inserts

Profiling operations with round inserts cannot be modeled by classical cutting forces mod- els, due to the important variation of cutting conditions along the active cutting edge. Edge discretisation principle is often used for modeling milling operations [1-5], but it can be also applied to turning. Then, local cutting conditions - as the uncut chip thickness h - are taken into account in the cutting relations used to calculate the local cutting forces.

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An Innovative Experimental Study of Corner Radius Effect on Cutting Forces

An Innovative Experimental Study of Corner Radius Effect on Cutting Forces

In this paper, the effect of the corner radius on the cutting forces has been studied using new original cutting configurations. The three approaches used – inverse identification, elementary tube and corner tests – show a significant increase of the local cutting forces with the nose radius for the highest values of r  , which is presumably coming from the indentation between the tool and the generated surface. On the opposite, the increase observed for the smallest values of r  could be due to the low lengths of the active cutting edge.
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An Innovative Experimental Study of Corner Radius Effect on Cutting Forces

An Innovative Experimental Study of Corner Radius Effect on Cutting Forces

In this paper, the effect of the corner radius on the cutting forces has been studied using new original cutting configurations. The three approaches used – inverse identification, elementary tube and corner tests – show a significant increase of the local cutting forces with the nose radius for the highest values of r  , which is presumably coming from the indentation between the tool and the generated surface. On the opposite, the increase observed for the smallest values of r  could be due to the low lengths of the active cutting edge.
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Utilization of a dynamometric pendulum to estimate cutting forces involved during routing. Comparison with actual calculated values

Utilization of a dynamometric pendulum to estimate cutting forces involved during routing. Comparison with actual calculated values

3. RESULTS AND DISCUSSIONS 3.1. Measurements on the router [9] At the beginning of this study, the aim was to take into account the influence of wood material in the estimation of cut- ting forces involved during routing. It was decided to work on wood mechanical properties involved during routing [10, 13, 22, 24], namely: Monnin hardness, fracture toughness in mode I, shearing and compression parallel to the grain. Cutting forces have been measured on routers (30 values for each species). Tests results were combined, (different mathematical models were tested) and several models were obtained. The highest significant correlation was obtained for the following equation using three properties : P f,I (elastic parameter in fracture tou- ghness), Ec (modulus of elasticity in compression), and SG (specific gravity) (in order to know if each factor was signifi- cantly separate in the correlation, a student test “t” was carried out). F c is total cutting forces during routing.
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Cutting Forces Parametric Model for the Dry High Speed Contour Milling of Aerospace Aluminium Alloys

Cutting Forces Parametric Model for the Dry High Speed Contour Milling of Aerospace Aluminium Alloys

Empiric-experimental parametric models are commonly obtained from the mathematical adjustment of experimental data to pre-established math functions. These models are useful for approximating and predicting the output variables when input variables change. So, in particular, parametric exponential models have shown a good adjustment for macrogeometrical deviations, such as straightness and parallelism, Sanchez-Sola et al. (2012), in the dry turning of Aluminium alloys. However, according to Salguero et al. (2011) and Campatelli et al. (2012), in the same processes, potential models present the best adjustment for other output variables such as roughness or cutting forces.
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Experimental and analytical combined thermal approach for local tribological understanding in metal cutting

Experimental and analytical combined thermal approach for local tribological understanding in metal cutting

and then machined parts resistance. Bacci da Silva and Wallbank [1] and Abukhshim et al. [2] review critically the main previous works focused on the development of experimental, analytical and numerical approaches devoted to the thermal problem of metal cutting. Analytical models are extensively reviewed by Komanduri and Hou, [3][4]; the main comments related to the analytical works are given in the following. These models are usually based on simplifying assumptions; they generally focus on a two-dimensional and steady state orthogonal cutting operation with simplified tool geometry. The cutting edge is assumed to be perfectly sharp and the rake face is flat. Tool or chip or workpiece are regarded as semi-infinite or infinite media. The material on each side of the primary shear zone is often supposed as two separate bodies in sliding contact; only few works assume it as the same body, [3] [5]. Both primary shear zone and secondary shear zone are considered as planes; tool-chip and tool-workpiece contact zones are currently supposed thermally perfect. Courbon et al. [6] propose an original approach for the tool- chip interface; this one is thermally perfect only for the sticking part of the contact zone whereas a thermal contact resistance is introduced for the sliding part. Generally the plastic deformation in the chip is neglected and the chip is supposed to move as a rigid body. Both tool and chip and workpiece free surfaces are generally regarded as adiabatic or rarely as convective heat transfer. Temperature distributions are currently predicted using Jaeger moving heat sources model [7].
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Tool wear and cutting forces when machining inconel 718 under cryogenic conditions: Liquid nitrogen and carbon dioxide

Tool wear and cutting forces when machining inconel 718 under cryogenic conditions: Liquid nitrogen and carbon dioxide

1 Faculty of Engineering, Mondragon Unibertsiatea, 20500 Mondragon, Spain. 2 Arts et Metiers, LAMPA, 2 boulevard du Ronceray, 49035 Angers, France. a) Corresponding author: schaabani@mondragon.edu Abstract. Nickel-based superalloys are widely exploited in turbojets components which are subjected to intense thermal and mechanical loadings during their operation. In fact, they exhibit excellent mechanical properties over a wide range of temperature and high corrosion and creep resistance. However, these materials induce several problems related to the shaping by machining due to essentially high heat resistance, high hardening tendency, high chemical affinity with tool material and low thermal conductivity leading to very high temperature in the cutting zone. In this context, assisted machining processes aim to improve the productivity of certain materials that are difficult to cut. Indeed, in order to keep the tool cold, it has been proposed to use cryogenic fluids (liquid nitrogen LN 2 and carbon dioxide CO 2 as coolant for effectively reducing temperatures since their vaporization temperatures
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Specific Cutting Forces of Isotropic and Orthotropic Engineered Wood Products by Round Shape Machining

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

Materials 2018, 11, 2575 3 of 14 The disk was machined using a 3-axis Numerical Control (NC) machine Record 1 (SCM Group, Rimini, Italy). The initially squared sample was made round by a spiral router bit with a chip-breaker. Once the sample was machined to a round shape, the surface was prepared by preliminary cuts in order to ensure the same initial conditions before doing the finishing cut and acquiring the cutting forces. Between the preparation cuts and the finishing cut, the disk was not disassembled so as not to introduce positioning errors. Both of these operations were done by a single straight blade balanced tool in order to obtain a constant chip thickness not influenced by multi blade tool run-off or blade misalignment. The diameter of the tool was 80 mm, and the blade was a tungsten carbide freshly sharpened insert with a rake angle of 25 ◦ and a blade angle of 55 ◦ . The surface preparation was done by five successive cuts at a spindle speed of 3000 rpm, a feeding speed of 1 m min −1 , and a radial depth of cut (reduced to “depth of cut” in the following) of 0.2 mm. The low feed speed and the low depth of cut allowed us to obtain a very thin chip thickness and to reduce as much as possible the formation of defects on the surface; those settings allowed us to avoid the influence of the preparation process on the measurements to be taken during the finishing.
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Effect of grain direction on cutting forces and chip geometry during green beech wood machining

Effect of grain direction on cutting forces and chip geometry during green beech wood machining

Force Measurement The dynamometer on which the knife was clamped presented a high resonance, and the cut solicitation spectrum included its natural frequency (1,657 Hz according to conducted hammer tests), leading to very dynamic force signals. To eliminate the dynamic component of the signal, it was averaged over the study area (the dynamic component being a symmetric oscillation around the average signal). Hence, the averaged parallel force (in the cutting direction) and the averaged tearing force (pulling the knife in its clamping direction, orthogonal to the parallel force in the cutting plan) were computed. The resulting force was calculated as the hypotenuse of the two previously quoted averaged forces. Since both the parallel and the tearing forces evolutions towards GD exhibit the exact same trends, the resultant force is used as appropriate descriptor for the subsequent analysis. The transversal force, out of the observation plane, was supposed to be null due to the system geometry (every element of the machining setup had been carefully aligned with the machine axis due to the use of a dial test indicator). In practice, over the 46 experiments, the mean transversal force was equal to 5.5 N, and the transversal force was slightly more than 100 times lower than the resulting force (displayed in next section). As a consequence, it was indeed neglected. In the following sections, every force mentioned is the average resulting force. Because of the heterogeneity of the wood samples, the forces were corrected by the specific gravity of the considered specimen with Eq. 3,
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Investigation of tool geometry effect and penetration strategies on cutting forces during thread milling

Investigation of tool geometry effect and penetration strategies on cutting forces during thread milling

Abstract The application of thread milling is increasing in industry because of its inherent advantages over other thread cutting techniques. The objective of this study is to investigate the effect of milling cutter tool geometry on cutting forces during thread milling. The proposed method can compare the performance of milling cutters in spite of the different number of tooth. The best thread milling cutter among the studied tools was determined from the cutting forces point of view. Furthermore, this study also pinpoints the best penetration strategy that provides minimum cutting forces. Lower cutting force variations will lead to fewer vibrations of the tool which in turn will produce accurate part.
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Independent analyses of cutting and friction forces applied on a single polycrystalline diamond compact cutter

Independent analyses of cutting and friction forces applied on a single polycrystalline diamond compact cutter

First of all, the experiments display results well established in the cutter/rock contact mechanics or more broadly in contact mechanics. The sliding friction coefficient is related to the inter- facial particles flow under the wear flat brought by the materials in contact. First, the friction coefficient does not depend on the ap- parent contact area (i.e. the wear flat area and the wear state) and is constant as soon as the conformity of the contact is performed (i.e. after few minutes here). Also, in function of the cutting depth, two cutting processes can be observed in which the cutting force is proportional to the cutting active area. The intrinsic specific en- ergy is the coefficient of proportionality which depends on the rock mechanical properties. In this way, the cutting forces depend on the compressive resistance of the rock. Eventually, the cutting coefficient is function of the cutter/rock contact geometry and does not depend on the excavated rock.
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Effect of the sand-blasting of edge peeling tools on the cutting forces and wear resistance

Effect of the sand-blasting of edge peeling tools on the cutting forces and wear resistance

Chafik LABIDI, Louis DENAUD, Corinne NOUVEAU, Robert COLLET, Laurent HENRY - Effect of the sand-blasting of edge peeling tools on the cutting forces and wear resistance - In:. Internatio[r]

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Towards cutting force evaluation without cutting tests

Towards cutting force evaluation without cutting tests

Considering that these estimations can be obtained without cutting tests once the ratio between K sv and u HS is known, the use of hat-shaped data can be an interesting way to establish a database for cutting force prediction and even for machinability classification if chip breakability is included. In this way, machined material groups will be defined depending on the ratio between the cutting coefficients and the volumetric hat-shaped strain energy. As this ratio may vary when changing the strain rate, the temperature or the dimensions of the samples, hat-shaped experiment standards should be defined in the future.
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3-Forces

3-Forces

La force exercée par un fil tendu est généralement appelée force de tension.  Mesure d’une force : On peut mesurer certaines forces à l’aide d’un dynamomètre. Il est composé de graduations qui relève la déformation d’un ressort proportionnel à l’intensité de la force à mesurer.

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A Preliminary Analysis of Molikpaq Local Ice Pressures and Ice Forces at Amauligak I-65.

A Preliminary Analysis of Molikpaq Local Ice Pressures and Ice Forces at Amauligak I-65.

Canadian Hydraulics Centre, National Research Council of Canada, Ottawa, Ontario ABSTRACT The Amauligak I-65 deployment of the Molikpaq for the winter of 1985/86 provides a good source of local pressure data and a basis for estimating global loads on a wide structure. Data including Medof panel pressures and hourly ice conditions at Molikpaq have been extracted from the “Catalogue of Local Ice Pressures” (CLIP) database. Pressures as high as 10 MPa were experienced on small areas; on areas greater than 3 m 2 , peak pressures are less than 2 MPa. A method is presented for the calculation of peak loads on the north and east faces, using local ice loads to obtain estimates of global face loads. Extreme values of global ice loads were of the order of 200 MN, with most ice forces during the season being much lower. Thicker ice generally corresponds to higher ice loads on both the east and north faces. However for the thickest ice, lower than expected forces were calculated for the faces of the structure. This could be due to less ice drift (and lower exposure) for very thick ice. INTRODUCTION
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Cutting Forces in basic and real life wood machining processes review, COST Action E35 2004-2008: Wood machining - Micromechanics and fracture

Cutting Forces in basic and real life wood machining processes review, COST Action E35 2004-2008: Wood machining - Micromechanics and fracture

Influence of the clearance angle δ on the orthogonal cutting forces distribution (Marchal and Negri 1997) in the case of peeling thin veneers (evergreen oak; nominal thickness = 0.6 mm[r]

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Analysis and Modelling of the Contact Radius Effect on the Cutting Forces in Cylindrical and Face Turning of Ti6Al4V Titanium Alloy

Analysis and Modelling of the Contact Radius Effect on the Cutting Forces in Cylindrical and Face Turning of Ti6Al4V Titanium Alloy

to tool-material pair method, defined by the NF-E66-520-4 standard [17]. The work material used is a Ti6Al4V titanium alloy workpiece. The homogeneity was verified by micro- hardness tests from the heart of the workpiece to the surface. This material is machined assisted with a Blaser Blasocut 2000 CF coolant, at low pressure. The cutting tool used for the tests is the LCGR1705-500-RP Seco Tools MDT round insert, used for profiling operations. The geometry has been measured and specified in Table 1. The cutting forces acquisition has been gathered with a Kistler type 9121 piezoelectric dynamometer and a Kistler 5019A amplifier. Table 1. Geometry of the LCGR1705-500-RP Seco Tool MDT insert on tool holder.
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Cutting Forces in basic and real life wood machining processes review, COST Action E35 2004-2008: Wood machining - Micromechanics and fracture

Cutting Forces in basic and real life wood machining processes review, COST Action E35 2004-2008: Wood machining - Micromechanics and fracture

Influence of the clearance angle on the orthogonal cutting forces distribution (Marchal and Negri 1997) in the case of peeling thin veneers (evergreen oak; nominal thickness = 0.6 mm[r]

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Substitution invariant cutting sequences

Substitution invariant cutting sequences

Construct, in the first quadrant of the plane, the square grid consisting of all vertical and horizontal lines through integer points. Label the intersections of y = /3x with the grid using 0 if the grid line crossed is vertical and 1 if it is horizontal. The sequence of labels, read from the origin out, is called the cutting sequence of y = 3x and is denoted here by In

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