https://sam.ensam.eu:443 The DSpace digital repository system captures, stores, indexes, preserves, and distributes digital research material. Sat, 18 Apr 2026 04:24:13 GMT 2026-04-18T04:24:13Z http://hdl.handle.net/10985/7469 Geometrical analysis of thread milling – Part 2:Calculation of uncut chip thickness FROMENTIN, Guillaume; POULACHON, Gerard Thread milling offers interesting possibilities for machining internal or external threads. This machining technique uses a mill with a triangular profile for metric threads and a helical interpolation strategy. Thus, the uncut chip thickness can not be easily evaluated from a simplified approach. The present study deals with a model for calculating uncut chip thickness during internal thread milling. This step is needed to understand and model the cutting forces. The model developed uses the geometrical definitions of the mill, and takes into account the milling mode and the cutting conditions. The link with the interferences between the tool and the thread is also established and corroborates a previous study. A full analyticalformulation of the problem is proposed, and results from different milling settings are presented. Fri, 01 Jan 2010 00:00:00 GMT http://hdl.handle.net/10985/7469 2010-01-01T00:00:00Z FROMENTIN, Guillaume POULACHON, Gerard Thread milling offers interesting possibilities for machining internal or external threads. This machining technique uses a mill with a triangular profile for metric threads and a helical interpolation strategy. Thus, the uncut chip thickness can not be easily evaluated from a simplified approach. The present study deals with a model for calculating uncut chip thickness during internal thread milling. This step is needed to understand and model the cutting forces. The model developed uses the geometrical definitions of the mill, and takes into account the milling mode and the cutting conditions. The link with the interferences between the tool and the thread is also established and corroborates a previous study. A full analyticalformulation of the problem is proposed, and results from different milling settings are presented. http://hdl.handle.net/10985/9625 Analysis and Modelling of the Contact Radius Effect on the Cutting Forces in Cylindrical and Face Turning of Ti6Al4V Titanium Alloy DORLIN, Théo; FROMENTIN, Guillaume; COSTES, Jean-Philippe Cutting forces are representative data to characterize machining operations.They have to be known to perform the part manufacturing. Therefore, cutting forces predictive models are useful and it is possible to optimize them by taking into account new parameters. Hence, this study deals with the geometrical modelling of tool-workpiece interaction and its influence on the cutting forces. The analysis focuses on convex contact radius between the machined part and the tool. Experiments are based on cylindrical and face turning of Ti6Al4V titanium alloy. The results highlight a significant influence of contact conditions on ploughing mechanisms, and consequently on the cutting forces intensity. This phenomenon is taken into account inthe suggested models, providing a better accuracy of cutting forces modelled. Thu, 01 Jan 2015 00:00:00 GMT http://hdl.handle.net/10985/9625 2015-01-01T00:00:00Z DORLIN, Théo FROMENTIN, Guillaume COSTES, Jean-Philippe Cutting forces are representative data to characterize machining operations.They have to be known to perform the part manufacturing. Therefore, cutting forces predictive models are useful and it is possible to optimize them by taking into account new parameters. Hence, this study deals with the geometrical modelling of tool-workpiece interaction and its influence on the cutting forces. The analysis focuses on convex contact radius between the machined part and the tool. Experiments are based on cylindrical and face turning of Ti6Al4V titanium alloy. The results highlight a significant influence of contact conditions on ploughing mechanisms, and consequently on the cutting forces intensity. This phenomenon is taken into account inthe suggested models, providing a better accuracy of cutting forces modelled. http://hdl.handle.net/10985/9561 Effect of rake angle on strain field during orthogonal cutting of hardened steel with c-BN tools BAIZEAU, Thomas; CAMPOCASSO, Sébastien; FROMENTIN, Guillaume; ROSSI, FREDERIC; POULACHON, Gerard In the case of hard machining of steels, negative rake tools generate compressive deformation and high temperature under the cutting edge, leading to phase transformation or ”white layers”. The resulting surface integrity can be predicted by numerical simulations which may be validated by comparing simulated and measured strain fields. Recent high speed imaging devices have facilitated strain field measurement by Digital Image Correlation (DIC), even at high strain rates. However, the analyse is generally restricted to the primary shear zone and not to the workpiece under the machined surface. For this study, a double-frame camera and a pulsed Nd:YAG laser, generally used in the field of fluid mechanics, have been employed to record images during an orthogonal cutting operation of a hardened steel. The effect of the rake angle and the edge preparation of c-BN tools on the subsurface displacement field, which has been experimentally investigated by using DIC, are presented in this paper together with an analysis on the origins of the strains. The results of these measurements will be used to validate cutting numerical simulations or to improve hybrid modelling of surface integrity. Thu, 01 Jan 2015 00:00:00 GMT http://hdl.handle.net/10985/9561 2015-01-01T00:00:00Z BAIZEAU, Thomas CAMPOCASSO, Sébastien FROMENTIN, Guillaume ROSSI, FREDERIC POULACHON, Gerard In the case of hard machining of steels, negative rake tools generate compressive deformation and high temperature under the cutting edge, leading to phase transformation or ”white layers”. The resulting surface integrity can be predicted by numerical simulations which may be validated by comparing simulated and measured strain fields. Recent high speed imaging devices have facilitated strain field measurement by Digital Image Correlation (DIC), even at high strain rates. However, the analyse is generally restricted to the primary shear zone and not to the workpiece under the machined surface. For this study, a double-frame camera and a pulsed Nd:YAG laser, generally used in the field of fluid mechanics, have been employed to record images during an orthogonal cutting operation of a hardened steel. The effect of the rake angle and the edge preparation of c-BN tools on the subsurface displacement field, which has been experimentally investigated by using DIC, are presented in this paper together with an analysis on the origins of the strains. The results of these measurements will be used to validate cutting numerical simulations or to improve hybrid modelling of surface integrity. http://hdl.handle.net/10985/9661 A generalised geometrical model of turning operations for cutting force modelling using edge discretisation CAMPOCASSO, Sébastien; COSTES, Jean-Philippe; FROMENTIN, Guillaume; BISSEY BRETON, Stéphanie; POULACHON, Gerard The knowledge of cutting forces is of prime importance to ensure the success of cutting operations, the desired properties of the machined parts and therefore the functionality of the workpieces. Edge discretisation is one way to model cutting forces. Traditionally used in milling, this methodology enables local changes in uncut chip thickness or cutting geometry to be taken into account and then gives suitable results in the three directions. A key point of this method is the geometrical transformation that enables the description of various tool geometries. This study proposes a geometrical model based on homogeneous matrices, whose main interest is to decompose the transformations step-by-step. The method, generalisable to all machining operations, is detailed for turning operations. Inserted cutters are modelled considering both the positioning of the insert and the local geometry of the insert. The cutting geometry and the edge are described using the same model in the machine coordinates system, allowing forces and moments to be calculated easily. Thu, 01 Jan 2015 00:00:00 GMT http://hdl.handle.net/10985/9661 2015-01-01T00:00:00Z CAMPOCASSO, Sébastien COSTES, Jean-Philippe FROMENTIN, Guillaume BISSEY BRETON, Stéphanie POULACHON, Gerard The knowledge of cutting forces is of prime importance to ensure the success of cutting operations, the desired properties of the machined parts and therefore the functionality of the workpieces. Edge discretisation is one way to model cutting forces. Traditionally used in milling, this methodology enables local changes in uncut chip thickness or cutting geometry to be taken into account and then gives suitable results in the three directions. A key point of this method is the geometrical transformation that enables the description of various tool geometries. This study proposes a geometrical model based on homogeneous matrices, whose main interest is to decompose the transformations step-by-step. The method, generalisable to all machining operations, is detailed for turning operations. Inserted cutters are modelled considering both the positioning of the insert and the local geometry of the insert. The cutting geometry and the edge are described using the same model in the machine coordinates system, allowing forces and moments to be calculated easily. http://hdl.handle.net/10985/7543 Micro-orthogonal Cutting of Metals KERMER, Daniel; FROMENTIN, Guillaume; LOUTAN, Olivier; AGEBEBIADE, Kossi; GIOVANOLA, Jacques High speed micromilling with single point or multi-edge cutting tools of diameters smaller than 300 m is finding increasing applications for the production of small very precise metallic parts. Because of the small value of the ratios cutting depth to cutting edge radius and cutting depth to characteristic microstructural dimensions, one may expect that the extensive technological data base available for conventional metal cutting, may not directly transfer to micromilling and that size effects will influence the cutting pressures in micromilling as compared to those in macromilling. To address this issue, we have developed a micro-orthogonal cutting test facility in which chip thickness can be controlled to within a few microns and cutting forces can be measured. Using this facility, we are conducting a rather fundamental investigation of micro cutting processes to identify possible size effects. Besides measuring specific cutting pressures, we also aim at identifying mechanisms of chip formation and how they are affected by microstructure, fracture damage accumulation and microtool geometry. We intend to contrast these observations with observations made in macro orthogonal cutting of the same materials as those tested in micro orthogonal cutting. This paper will describe the test facility and present preliminary results obtained during micro-orthogonal cutting experiments. Collaboration avec l'EPFL Tue, 01 Jan 2008 00:00:00 GMT http://hdl.handle.net/10985/7543 2008-01-01T00:00:00Z KERMER, Daniel FROMENTIN, Guillaume LOUTAN, Olivier AGEBEBIADE, Kossi GIOVANOLA, Jacques High speed micromilling with single point or multi-edge cutting tools of diameters smaller than 300 m is finding increasing applications for the production of small very precise metallic parts. Because of the small value of the ratios cutting depth to cutting edge radius and cutting depth to characteristic microstructural dimensions, one may expect that the extensive technological data base available for conventional metal cutting, may not directly transfer to micromilling and that size effects will influence the cutting pressures in micromilling as compared to those in macromilling. To address this issue, we have developed a micro-orthogonal cutting test facility in which chip thickness can be controlled to within a few microns and cutting forces can be measured. Using this facility, we are conducting a rather fundamental investigation of micro cutting processes to identify possible size effects. Besides measuring specific cutting pressures, we also aim at identifying mechanisms of chip formation and how they are affected by microstructure, fracture damage accumulation and microtool geometry. We intend to contrast these observations with observations made in macro orthogonal cutting of the same materials as those tested in micro orthogonal cutting. This paper will describe the test facility and present preliminary results obtained during micro-orthogonal cutting experiments. http://hdl.handle.net/10985/9114 Analysis of chip formation mechanisms and modelling of slabber process PFEIFFER, Renaud; COLLET, Robert; DENAUD, Louis; FROMENTIN, Guillaume During the primary transformation in wood industry, logs are faced with conical rough milling cutters commonly named slabber or canter heads. Chips produced consist of raw materials for pulp paper and particleboard industries. The process efficiency of these industries partly comes from particle size distribution. However, chips formation is greatly dependent on milling conditions and material variability. Thus, this study aims at better understanding and predicting chips production in wood milling. The different mechanisms of their formation are studied through orthogonal cutting experiments at high cutting speed for beech and Douglas fir. Within these conditions, ejection of free water inside wood can be observed during fragmentation, particularly on beech. As previously seen in quasi-static experiments, chip thickness is proportional to the nominal cut thickness. Moreover, the grain orientation has a great influence on the cutting mechanisms, so as the nominal cut and the grows rings widths. This chip fragmentation study finally allows the improvement of the cutting conditions in rough milling. In order to optimize machine design as well as cutting geometry, a geometrical model of a generic slabber head is developed. This model allows the study of the effective cutting kinematics, the log-cutting edges interactions and the effective wood grain direction during cutting. This paper describes the great influence of the carriage position on cutting conditions. The results obtained here can be directly used by milling machine manufacturers. Wed, 01 Jan 2014 00:00:00 GMT http://hdl.handle.net/10985/9114 2014-01-01T00:00:00Z PFEIFFER, Renaud COLLET, Robert DENAUD, Louis FROMENTIN, Guillaume During the primary transformation in wood industry, logs are faced with conical rough milling cutters commonly named slabber or canter heads. Chips produced consist of raw materials for pulp paper and particleboard industries. The process efficiency of these industries partly comes from particle size distribution. However, chips formation is greatly dependent on milling conditions and material variability. Thus, this study aims at better understanding and predicting chips production in wood milling. The different mechanisms of their formation are studied through orthogonal cutting experiments at high cutting speed for beech and Douglas fir. Within these conditions, ejection of free water inside wood can be observed during fragmentation, particularly on beech. As previously seen in quasi-static experiments, chip thickness is proportional to the nominal cut thickness. Moreover, the grain orientation has a great influence on the cutting mechanisms, so as the nominal cut and the grows rings widths. This chip fragmentation study finally allows the improvement of the cutting conditions in rough milling. In order to optimize machine design as well as cutting geometry, a geometrical model of a generic slabber head is developed. This model allows the study of the effective cutting kinematics, the log-cutting edges interactions and the effective wood grain direction during cutting. This paper describes the great influence of the carriage position on cutting conditions. The results obtained here can be directly used by milling machine manufacturers. http://hdl.handle.net/10985/10925 Orthogonal cutting simulation of OFHC copper using a new constitutive model considering the state of stress and the microstructure effects DENGUIR, Lamice; MARTINS DO OUTEIRO, Jose Carlos; FROMENTIN, Guillaume; VIGNAL, Vincent; BESNARD, Rémy This work aims to develop an orthogonal cutting model for surface integrity prediction, which incorporates a new constitutive model of Oxygen Free High Conductivity (OFHC) copper. It accounts for the effects of the state of stress on the flow stress evolution up to fracture. Moreover, since surface integrity parameters are sensitive to the microstructure of the work material, this constitutive model highlights also the recrystallization effects on the flow stress. Orthogonal cutting model is validated using experimental designed cutting tests. More accurate predictions were obtained using this new constitutive model comparing to the classical Johnson-Cook model. Fri, 01 Jan 2016 00:00:00 GMT http://hdl.handle.net/10985/10925 2016-01-01T00:00:00Z DENGUIR, Lamice MARTINS DO OUTEIRO, Jose Carlos FROMENTIN, Guillaume VIGNAL, Vincent BESNARD, Rémy This work aims to develop an orthogonal cutting model for surface integrity prediction, which incorporates a new constitutive model of Oxygen Free High Conductivity (OFHC) copper. It accounts for the effects of the state of stress on the flow stress evolution up to fracture. Moreover, since surface integrity parameters are sensitive to the microstructure of the work material, this constitutive model highlights also the recrystallization effects on the flow stress. Orthogonal cutting model is validated using experimental designed cutting tests. More accurate predictions were obtained using this new constitutive model comparing to the classical Johnson-Cook model. http://hdl.handle.net/10985/9562 Computerized Simulation of Interference in Thread Milling of Non-Symmetric Thread Profiles FROMENTIN, Guillaume; DOEBBELER, Benjamin; LUNG, Dieter Thread milling is a machining technique which is becoming widely used in specific contexts such as large diameter threading. Furthermore, compared to tapping, it is fully adapted to produce internal threads in difficult-to-cut materials, because the tool can be easily removed if a breakage occurs. For thread milling, as well as for form milling, groove and worm machining, geometrical considerations are critical aspects to succeed surface machining with the required accuracy. Interference phenomena may appear and appropriate cutter profiles and tool trajectories have to be defined to generate the desired shape. The proposed study is focusing on the threading of non-symmetric profile. A geometrical model computing the envelope profiles and using full parametrical definitions of the tool and thread is proposed. Its exploitation allows an analysis to explain and to quantify the influencing parameters on overcut. Then, an iterative method based on a direct approach, is proposed to define the tool design allowing to machine non-symmetric threads with good accuracy. Article fait en collaboration avec WZL, RWTH Aachen, Allemagne pendant mon CRCT. Thu, 01 Jan 2015 00:00:00 GMT http://hdl.handle.net/10985/9562 2015-01-01T00:00:00Z FROMENTIN, Guillaume DOEBBELER, Benjamin LUNG, Dieter Thread milling is a machining technique which is becoming widely used in specific contexts such as large diameter threading. Furthermore, compared to tapping, it is fully adapted to produce internal threads in difficult-to-cut materials, because the tool can be easily removed if a breakage occurs. For thread milling, as well as for form milling, groove and worm machining, geometrical considerations are critical aspects to succeed surface machining with the required accuracy. Interference phenomena may appear and appropriate cutter profiles and tool trajectories have to be defined to generate the desired shape. The proposed study is focusing on the threading of non-symmetric profile. A geometrical model computing the envelope profiles and using full parametrical definitions of the tool and thread is proposed. Its exploitation allows an analysis to explain and to quantify the influencing parameters on overcut. Then, an iterative method based on a direct approach, is proposed to define the tool design allowing to machine non-symmetric threads with good accuracy. http://hdl.handle.net/10985/8405 Influence of cutting process mechanics on surface integrity and electrochemical behavior of OFHC copper DENGUIR, Lamice; FROMENTIN, Guillaume; MARTINS DO OUTEIRO, Jose Carlos; VIGNAL, Vincent; BESNARD, Rémy Superfinishing machining has a particular impact on cutting mechanics, surface integrity and local electrochemical behavior. In fact, material removal during this process induces geometrical, mechanical and micro-structural modifications in the machined surface and sub-surface. However, a conventional 3D cutting process is still complex to study in terms of analytical/numerical modeling and experimental process monitoring. So, researchers are wondering if a less intricate configuration such as orthogonal cutting would be able to provide information about surface integrity as close as possible to that one generated by a 3D cutting process. For that reason, in the present paper, two different machining configurations were compared: face turning and orthogonal cutting. The work material is oxygen free high conductivity copper (OFHC) and the cutting tools are uncoated cemented carbide. The research work was performed in three steps. In the first step, the process mechanics of superfinishing machining of OFHC copper was performed. In the second step, the surface integrity and the chemical behavior of the machined samples were analyzed. Finally, in the third step, correlations between input parameters and output measures were conducted using statistical techniques. Results show that when applying low ratios between the uncut chip thickness and the cutting edge radius, the surface integrity and cutting energy are highly affected by the ploughing phenomenon. Otherwise, the most relevant cutting parameter is the feed. In order to compare face turning with orthogonal cutting, a new geometrical parameter was introduced, which has a strong effect in the electrochemical behavior of the machined surface. The authors gratefully acknowledge the support received from IC ARTS and CEA Valduc Wed, 01 Jan 2014 00:00:00 GMT http://hdl.handle.net/10985/8405 2014-01-01T00:00:00Z DENGUIR, Lamice FROMENTIN, Guillaume MARTINS DO OUTEIRO, Jose Carlos VIGNAL, Vincent BESNARD, Rémy Superfinishing machining has a particular impact on cutting mechanics, surface integrity and local electrochemical behavior. In fact, material removal during this process induces geometrical, mechanical and micro-structural modifications in the machined surface and sub-surface. However, a conventional 3D cutting process is still complex to study in terms of analytical/numerical modeling and experimental process monitoring. So, researchers are wondering if a less intricate configuration such as orthogonal cutting would be able to provide information about surface integrity as close as possible to that one generated by a 3D cutting process. For that reason, in the present paper, two different machining configurations were compared: face turning and orthogonal cutting. The work material is oxygen free high conductivity copper (OFHC) and the cutting tools are uncoated cemented carbide. The research work was performed in three steps. In the first step, the process mechanics of superfinishing machining of OFHC copper was performed. In the second step, the surface integrity and the chemical behavior of the machined samples were analyzed. Finally, in the third step, correlations between input parameters and output measures were conducted using statistical techniques. Results show that when applying low ratios between the uncut chip thickness and the cutting edge radius, the surface integrity and cutting energy are highly affected by the ploughing phenomenon. Otherwise, the most relevant cutting parameter is the feed. In order to compare face turning with orthogonal cutting, a new geometrical parameter was introduced, which has a strong effect in the electrochemical behavior of the machined surface. http://hdl.handle.net/10985/7495 A force model for superfinish turning of pure copper with rounded edge tools at low feed rate GERMAIN, Dimitri; FROMENTIN, Guillaume; POULACHON, Gerard; BISSEY BRETON, Stéphanie This paper presents a model for force prediction of superfinish turning operation on pure copper. The model is divided in two parts. The first part computes the forces acting on the rake face of the tool. The second part computes the forces on the clearance face that are much more important in superfinish machining than in conventional machining. Fri, 01 Jan 2010 00:00:00 GMT http://hdl.handle.net/10985/7495 2010-01-01T00:00:00Z GERMAIN, Dimitri FROMENTIN, Guillaume POULACHON, Gerard BISSEY BRETON, Stéphanie This paper presents a model for force prediction of superfinish turning operation on pure copper. The model is divided in two parts. The first part computes the forces acting on the rake face of the tool. The second part computes the forces on the clearance face that are much more important in superfinish machining than in conventional machining.