Philippe Darnis - Academia.edu (original) (raw)

Papers by Philippe Darnis

Procedia CIRP, 2013

In the manufacturing process the interaction tool/chip/machine-tool generates cutting forces and ... more In the manufacturing process the interaction tool/chip/machine-tool generates cutting forces and also moments (a complete torsor) on the tool in three directions. These moments represent a significant proportion of energy consumed in cutting process. The aim of this paper is a dynamic analysis applied to the mechanical actions (the complete torsor) and the mechanical vibrations to develop a monitoring and diagnosis approach in three-dimensional case. The method used in our research refers to an advanced analysis of mechanical actions to obtain the response of the milling tool during the cutting process and also to identify various defects. An important approach in monitoring process is based on the synchronous envelope (SEA) applied on cutting vibration continuing with the dynamic analysis of the moments. To understand the dynamic phenomena due to the milling process a complex experimental protocol and analysis is designed and realized.

Dans le processus de fabrication par enlèvement de matière sur machines-outils, l'apparition des ... more Dans le processus de fabrication par enlèvement de matière sur machines-outils, l'apparition des vibrations est inévitable. Dans les situations où l'amplitude dépasse les limites de la précision dimensionnelle, le phénomène vibratoire est préjudiciable. L'étude expérimentale présentée ici permet d'identifier les principaux paramètres relatifs au comportement dynamique du système usinant. La localisation des déplacements de la pointe de l'outil dans un plan est démontrée grâce aux résultats expérimentaux. L'existence de ce plan et les corrélations avec les caractéristiquesélastiques du système usinant permettent de simplifier le modèle dynamique 3D. Avec l'approche expérimentale réalisée, un modèle dynamique est proposé en concordance avec les résultats expérimentaux.

Conference code: 86584, Export Date: 21 October 2011, Source: Scopus, doi: 10.1016/j.proeng.2011.... more Conference code: 86584, Export Date: 21 October 2011, Source: Scopus, doi: 10.1016/j.proeng.2011.04.381, Language of Original Document: English, Correspondence Address: Royer, R.; Université de Bordeaux, I2M - MPI, UMR CNRS 5295, 351 Cours de la Libration, 33405 Talence, France; email: raphael.royer@u-bordeaux1.fr, References: Cahuc, O., Darnis, P., Gérard, A., Battaglia, J.-L., Experimental and analytical balance sheet in turning applications (2001) Int. J. Adv. Manuf. Technol., 18 (9), pp. 648-656;

International Optical Design Conference and Optical Fabrication and Testing, 2010

... 3D metrology Jean-Philippe Champreux ab*, Olivier Cahuc a, Philippe Darnis b, Jean-Yves K&#x2... more ... 3D metrology Jean-Philippe Champreux ab*, Olivier Cahuc a, Philippe Darnis b, Jean-Yves K'nevez a, Raynald Laheurte ab, Nathalie Darbois c, Jérôme Néauport c ... Figure 2 illustrates that after the first etching the maximum of fracture have been removed. ...

International Journal of Forming Processes, 2007

ABSTRACT In order to optimize drill geometry according to cutting resistance, experiments have be... more ABSTRACT In order to optimize drill geometry according to cutting resistance, experiments have been carried out, trying to evaluate the influence of local edge angles (direction and rake). Many works deal with drill point geometry models, however, some of them have a ...

International Journal of Material Forming, 2008

Optics Express, 2013

Relationships between subsurface damage (SSD) depth and peak to valley surface roughness (Rt) hav... more Relationships between subsurface damage (SSD) depth and peak to valley surface roughness (Rt) have been widely studied and present a major interest for an easy assessment of the SSD depth. We look at the relation between SSD depth and other surface roughness parameters using the Abbott-Firestone curve on a large campaign of grinding tests (with different abrasive grain size, grinding speed and grinding mode). The results reveal that Abbott-Firestone parameters are better for an assessment of SSD depth and that relationships between SSD depth and surface roughness are not universal but depend on the grinding process.

ABSTRACT Dans le cadre de l'optimisation des conditions de coupe en fraisage, la maîtrise... more ABSTRACT Dans le cadre de l'optimisation des conditions de coupe en fraisage, la maîtrise des grandeurs énergétiques mises en jeu lors de l'usinage est essentielle. Pour ceci, les paramètres géométriques et cinématiques doivent être identifiés et contrôlés afin de vérifier leur influence sur l'ensemble des actions mécaniques de coupe. L'étude présentée constitue une première étape dont l'objectif final est l'élaboration d'un critère énergétique caractérisant l'ensemble des actions de coupe, et ceci indépendamment des conditions cinématiques d'usinage, permettant ainsi l'optimisation de celles-ci et la transposition des résultats vers une autre configuration. Le but de ces travaux est donc de mieux appréhender les phénomènes mis en jeu dans le cas du fraisage, où la coupe n'est pas continue, et où l'optimisation du procédé devient alors délicate. Nos études antérieures [Cahuc et al., 2000] ayant démontré l'existence des six composantes des actions de coupe, cette étude expérimentale s'intéresse tout particulièrement aux phénomènes influençant l'ensemble des actions de coupe.

Optifab 2013, 2013

ABSTRACT Relationships between subsurface damage (SSD) depth and peak to valley surface roughness... more ABSTRACT Relationships between subsurface damage (SSD) depth and peak to valley surface roughness (Rt) have been widely studied and present a major interest for an easy assessment of the SSD depth. We seek the relation between SSD depth and other surface roughness parameters using the Abbott-Firestone curve on a large campaign of grinding tests (with different abrasive grain size, grinding speed and grinding mode). The results reveal that the Abbott-Firestone parameter Mr2, which can be linked to the volume fraction of valley in the roughness profile, is more accurate than Rt for an assessment of the SSD depth and that the relationship between Mr2 and the SSD depth varies when changing the grinding mode.

International Journal of Material Forming, 2009

Many studies simulates the machining process by using a single degree of freedom spring-mass syst... more Many studies simulates the machining process by using a single degree of freedom spring-mass system to model the tool stiffness, or the workpiece stiffness, or the unit tool-workpiece stiffness in modelings 2D. Others impose the tool action, or use more or less complex modelings of the efforts applied by the tool taking account the tool geometry. Thus, all these models remain two-dimensional or sometimes partially three-dimensional. This paper aims at developing an experimental method allowing to determine accurately the real three-dimensional behaviour of a machining system (machine tool, cutting tool, tool-holder and associated system of force metrology six-component dynamometer). In the work-space model of machining, a new experimental procedure is implemented to determine the machining system elastic behaviour. An

Proceedings of SPIE - The International Society for Optical Engineering, 2008

ABSTRACT During the development of the laser megajoule (LMJ), a high power laser facility dedicat... more ABSTRACT During the development of the laser megajoule (LMJ), a high power laser facility dedicated to DT fusion, CEA has made important efforts to understand and improve laser induced damage threshold of fused silica optics at the wavelength of 351 nm. For several years, with various industrials and academics partners, we have focused on optimizing the grinding, lapping and polishing processes to increase materials performance. In this paper, we describe our efforts in various fields: subsurface damage characterization, lapping process simulation, diamond grinding and lapping machine instrumentations, ... Our concern is to control and manage the material removal at each step of the process in order to reduce the cracks region extension and thus to diminish the damage density.

Mécanique & Industries, 2007

Tél : 05 40 00 62 23 Résumé Dans le processus de fabrication par enlèvement de matière sur machin... more Tél : 05 40 00 62 23 Résumé Dans le processus de fabrication par enlèvement de matière sur machinesoutils, l'apparition des vibrations est inévitable. Dans les situations où l'amplitude dépasse les limites de la précision dimensionnelle, le phénomène vibratoire est préjudiciable. L'étude expérimentale présentée ici permet d'identifier les principaux paramètres relatifs au comportement dynamique du système usinant. La localisation des déplacements de la pointe de l'outil dans un plan est démontrée grâce aux résultats expérimentaux. L'existence de ce plan et les corrélations avec les caractéristiques élastiques du système usinant permettent de simplifier le modèle dynamique 3D. Avec l'approche expérimentale réalisée, un modèle dynamique est proposé en concordance avec les résultats expérimentaux.

ABSTRACT Machining is the most common manufacturing process. A good behaviour law is necessary in... more ABSTRACT Machining is the most common manufacturing process. A good behaviour law is necessary in the simulation of machining processes (analytical and finite element modeling). Usually, commonly used behaviour laws such as Jonhson-Cook can bring unsatisfactory results especially for high strain and large deformation processes. Significant differences can appear between experimental and simulation results. The aim of this paper is to present the choices made regarding the behaviour law in this context. This study develops a large deformation strain-gradient theoretical framework with hypothesis linked to metal cutting processes. The theoretical framework has the potential of expressing moments at the tool tip as they were observed in experiments. It will be shown that the theory has the capability of interpreting the complex phenomena found in machining and more particularly in high speed machining.