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Simulation of machining processes at global scale using SAMCEF for machining Masset, Luc ; Debongnie, Jean-François (2008, November) SAMCEF for Machining is a professional solution dedicated to process engineers. This Computer Aided Engineering tool focuses on the simulation of the machined part behavior at a global scale. Several ... [more ▼] SAMCEF for Machining is a professional solution dedicated to process engineers. This Computer Aided Engineering tool focuses on the simulation of the machined part behavior at a global scale. Several aspects of machining are taken into account such as form errors, chatter or thermal aspects. In this paper, we present a few industrial applications that demonstrate the benefits of simulation in production planning : reduction of setup delays, limitation of experimental validations, cost reduction. [less ▲] Detailed reference viewed: 111 (17 ULg)Défauts d'orientation et de battement Debongnie, Jean-François Report (2008) The problem of orientation or runout errors being formulated, it is firt noted that these errors necessarily include the form errors of the measured part. The second problem is the correct asseement of a ... [more ▼] The problem of orientation or runout errors being formulated, it is firt noted that these errors necessarily include the form errors of the measured part. The second problem is the correct asseement of a simulated reference when the reference surface is of imperfect form. The logical choice would be perfect form having the least maximal distance to the physical one. But this choice being a difficult one, the best approximation in the least square sense if often chosed. The effect of this reference perturbation is studied. [less ▲] Detailed reference viewed: 50 (2 ULg)Théorie des erreurs de rectitude et de planéité Debongnie, Jean-François Report (2008) This report is focused on straightness and flatness errors, in a common frame. Starting with the framing of a compact of a 2-D or 3-D space by two parallel hyperplanes, it is first noted that the given ... [more ▼] This report is focused on straightness and flatness errors, in a common frame. Starting with the framing of a compact of a 2-D or 3-D space by two parallel hyperplanes, it is first noted that the given compact may be replaced by its convex closure. It is then proved that the separation of the framing hyperplanes varies continuously with their common normal vector. From this follows that a minimal separation is reached for a given orientation of the hyperplanes. However, this optimal orientation is not necessary unique. An optimality criterium is obtained, which concerns the number and the position of the contact points of the given surfave with the framing hyperplanes. Finally, a direct method of obtaining the optimum is presented. [less ▲] Detailed reference viewed: 143 (2 ULg)Théorie de l'erreur de circularité Debongnie, Jean-François Report (2008) This report gives the theory of the circularity error, as defined by ISO-norms, that is, the minimum of the radius difference between two concentric circles that enclose the measured curve. The common ... [more ▼] This report gives the theory of the circularity error, as defined by ISO-norms, that is, the minimum of the radius difference between two concentric circles that enclose the measured curve. The common center of the optimal pair of circles being called the best center, the question of its existence is fully discussed. It is then proved that this problem is equivalent to the research of a circle which is the best approximation of the given curve by respect of a uniform norm. A characterization of the best center is developed, from which the unicity of the best center is proved. [less ▲] Detailed reference viewed: 231 (6 ULg)A smoothed finite element method for plate analysis ; ; et al in Computer Methods in Applied Mechanics & Engineering (2008), 197(13-16), 1184-1203 A quadrilateral element with smoothed curvatures for Mindlin-Reissner plates is proposed. The curvature at each point is obtained by a non-local approximation via a smoothing function. The bending ... [more ▼] A quadrilateral element with smoothed curvatures for Mindlin-Reissner plates is proposed. The curvature at each point is obtained by a non-local approximation via a smoothing function. The bending stiffness matrix is calculated by a boundary integral along the boundaries of the smoothing elements (smoothing cells). Numerical results show that the proposed element is robust, computational inexpensive and simultaneously very accurate and free of locking, even for very thin plates. The most promising feature of our elements is their insensitivity to mesh distortion. (c) 2007 Elsevier B.V. All rights reserved. [less ▲] Detailed reference viewed: 191 (16 ULg)Providing stability maps for milling operations ; ; Debongnie, Jean-François in International Journal of Machine Tools & Manufacture (2007), 47(9), 1493-1496 This article presents a new stability prediction tool. The method is based on the dynamic behaviour of both milling tool and workpiece, computed using finite element method. Dynamic behaviour is expressed ... [more ▼] This article presents a new stability prediction tool. The method is based on the dynamic behaviour of both milling tool and workpiece, computed using finite element method. Dynamic behaviour is expressed under the form of transfer functions and used to predict stability lobes at each tool position. The unconditionally stable depth of cut is then stored and displayed on a graphic representation of the machined surface under the form of colour axis, named stability map. An application of the method on a Renault cylinder block is presented as an illustration. (C) 2006 Elsevier Ltd. All rights reserved. [less ▲] Detailed reference viewed: 94 (2 ULg)Un algorithme performant de calcul des erreurs de forme Debongnie, Jean-François in Agouzoul, Mohammed (Ed.) Proceedings du 8e Congrès de Mécanique. Volume I. Mécanique des Solides (2007, April) In this paper, an original algorithm for the computation of a form error is exposed, which is exceptionally fast and robust and which wholly conforms to ISO norms. Detailed reference viewed: 66 (4 ULg)Conception mécanique - Fascicule 2 : Quelques repères Debongnie, Jean-François Book published by DEBONGNIE (JEAN-FRANCOIS) (2007) Tables, diagrams and summerized methods for the design of machine elements. The different sections are: 1) Normal numbers; 2) Tolerances; 3) Alloys designation; 4) Rolling bearings; 5) Plane bearings; 6 ... [more ▼] Tables, diagrams and summerized methods for the design of machine elements. The different sections are: 1) Normal numbers; 2) Tolerances; 3) Alloys designation; 4) Rolling bearings; 5) Plane bearings; 6) Hub/shaft assemblies; 7) Bolts; 8) Welds; 9) Shafts; 10) Fatigue (including a large stress concentration atlas); 11) Hertzian contacts; 12) Wear; 13) Belts; 14) Gears. [less ▲] Detailed reference viewed: 519 (38 ULg)Conception mécanique - fascicule 1 : cours Debongnie, Jean-François Book published by DEBONGNIE (JEAN-FRANCOIS) (2007) This book presents the basic rules of machine design Detailed reference viewed: 3263 (90 ULg)Compléments de Fabrication mécanique et F.A.O. - Partie Usinage Debongnie, Jean-François Learning material (2007) Numerical command of machine tools : principles. Introduction to I.S.O. coding of machine tools. Tolerances. Tolerance stacking for manufacturing processes. Non conventional machining processes. Detailed reference viewed: 232 (15 ULg)Mechanical based circular notch hinge design ; ; Debongnie, Jean-François et al Report (2007) At the microscale, classical bearings such as ball bearings, sliding bearings and other pivots may be difficult to manufacture. Among all possible solutions to replace them, the notch hinge seems to be ... [more ▼] At the microscale, classical bearings such as ball bearings, sliding bearings and other pivots may be difficult to manufacture. Among all possible solutions to replace them, the notch hinge seems to be very attractive through its many advantages. The major limitation is on the rotation angle. This paper presents a new simplified analytical model for the prediction of the maximum angular displacement and the angular stiffness of a notch hinge. To validate our model, an experimental set-up has been developed. Finally, the results are compared to other theories. [less ▲] Detailed reference viewed: 144 (3 ULg)Dual analysis for finite element solutions of plate bending Debongnie, Jean-François ; ; in Topping, B. H. V.; Montero, G.; Montenegro, R. (Eds.) Proceedings of the Eighth International Conference on Computational Structures Technology (2006, September) This paper presents the application of the dual analysis concept to plate bending. In this method, a same problem is analyzed parallely by a displacement and an equilibrium model. The energetic distance ... [more ▼] This paper presents the application of the dual analysis concept to plate bending. In this method, a same problem is analyzed parallely by a displacement and an equilibrium model. The energetic distance between these two models is the sum of both global errors and consequently, an upper bound of each of them. After an exposition of the two models, numerical examples are presented, which illustrate the high obtainable accuracy of the method. [less ▲] Detailed reference viewed: 61 (9 ULg)A stability diagram computation method for milling adapted to automotive industry ; ; Debongnie, Jean-François Conference (2006, June) In this paper, a numerical method to compute stability diagrams is presentd. It is adapted to the particular case of automotive parts production where chatter arises due to the lack of stiffness of the ... [more ▼] In this paper, a numerical method to compute stability diagrams is presentd. It is adapted to the particular case of automotive parts production where chatter arises due to the lack of stiffness of the workpiece. The main features of the model are the simultaneous immersion of many teeth, frequency domain computations and the use of the Finite Element Method to provide transfer function. [less ▲] Detailed reference viewed: 145 (2 ULg)Usinage Debongnie, Jean-François Book published by CEFAL (2006) La technologie, science des fabrications, est un élément indispensable de la formation des ingénieurs mécaniciens et électromécaniciens, en liaison avec les cours de conception mécanique. L'usinage, qui ... [more ▼] La technologie, science des fabrications, est un élément indispensable de la formation des ingénieurs mécaniciens et électromécaniciens, en liaison avec les cours de conception mécanique. L'usinage, qui représente soixante pour cent des opérations de fabrication, en est une partie importante. Première contact des étudiants avec la fabrication, ce livre comprend d'abord une partie descriptive où sont exposées les principales techniques d'usinage. Une seconde partie est consacrée à la théorie de la coupe. La démarche est progressive et part d'un modèle fort simple, puis l'enrichit petit à petit pour traiter successivement le tournage, le perçage, le fraisage et la rectification. L'ouvrage comporte près de deux cent cinquante illustrations. Son contenu est enrichi de résultats obtenus par l'équipe de recherche de l'auteur. Il ouvre la porte à l'étude des méthodes de fabrication et de la fabrication assistée par ordinateur. [less ▲] Detailed reference viewed: 732 (75 ULg)An efficient simulation tool for predicting chatter during cutting operations ; Masset, Luc ; et al Conference (2006, April) The trends in chatter prediction are to compute stability lobes showing the maximal depth of cut versus spindle speed, following the work of Tlusty, Tobias and, more recently, Altintas. For mass ... [more ▼] The trends in chatter prediction are to compute stability lobes showing the maximal depth of cut versus spindle speed, following the work of Tlusty, Tobias and, more recently, Altintas. For mass production such as the production of automotive parts, this kind of approach is not suitable because the goal is to find cutting conditions stable and independent of perturbations inherent to machining (clamping, rough part dimensions...). Still, in this method, the greatest allowable depth of cut to avoid chatter at any spindle speed is considered. The model is based on Tlusty's theory and the local stiffness of the machined surface is computed through a static finite element analysis. The result is a chatter map of the machined surface showing the maximal depth of cut at each node. [less ▲] Detailed reference viewed: 118 (5 ULg)Mise à forme des matériaux - Première partie Debongnie, Jean-François Learning material (2006) Introduction. Irons metallurgy and alloys classifications (DIN, AFNOR, SAE). Casting practice. Forging. Sheet-metal working. Welding, soldering and oxygen cutting. Polder metallurgy. Unconventional ... [more ▼] Introduction. Irons metallurgy and alloys classifications (DIN, AFNOR, SAE). Casting practice. Forging. Sheet-metal working. Welding, soldering and oxygen cutting. Polder metallurgy. Unconventional machining processes. [less ▲] Detailed reference viewed: 631 (74 ULg)Prédiction numérique des défauts de forme engendrés par l'usinage Debongnie, Jean-François ; Masset, Luc in Actes du 7ème Congrès de Mécanique. Volume I. Mécanique des Solides (2005, April) Presentation of a prediction method of form errors arising during machining which has been developed in the manufacturing laboratory of the University of Liège. It combines empirical force models and a ... [more ▼] Presentation of a prediction method of form errors arising during machining which has been developed in the manufacturing laboratory of the University of Liège. It combines empirical force models and a finite element model of the machined part. A particularly efficient solution scheme has been developed, leading to a valuable tool for the industry. [less ▲] Detailed reference viewed: 97 (9 ULg)Machining process simulation using Samcef superelement Masset, Luc ; Debongnie, Jean-François ; Conference (2005, February) In this paper, we present a new simulation tool for process engineers. During process design phases, several aspects of machining have to be taken into account. Classical CAD/CAM suites still lack some ... [more ▼] In this paper, we present a new simulation tool for process engineers. During process design phases, several aspects of machining have to be taken into account. Classical CAD/CAM suites still lack some crucial issues. The goal of the developed tool is to predict the geometric errors of machined surfaces. For classical applications of the automotive domain, form errors are mainly due to the machined part and clamping system flexibility. They are modeled thanks to the FE method. The major peculiarity of the adopted model is to apply numerous load cases. To achieve a low computational coast, we have combined the SAMCEF superelement feature and a specific code to solve the reduced system. This original scheme allows solving efficiently large industrial applications. [less ▲] Detailed reference viewed: 150 (10 ULg)Eléments finis tétraédriques pour l'analyse duale ; Beckers, Pierre ; Debongnie, Jean-François in Revue Européenne des Éléments Finis (2004), 13(5/6/7), 547-558 The error estimation by pure dual analysis requires two finite element computations. It is based on the results of displacement and equilibrium approaches of a given problem. It allows to compute the ... [more ▼] The error estimation by pure dual analysis requires two finite element computations. It is based on the results of displacement and equilibrium approaches of a given problem. It allows to compute the cumulated global discretization error of the two models by a simple comparison of the total energies computed using both methods. This paper presents the development of a new family of equilibrium type tetrahedral finite elements leading to statically admissible solutions of 3D finite element problems. Two examples of dual analysis using these elements are also presented. [less ▲] Detailed reference viewed: 80 (12 ULg)The equilibrium finite element model and error estimation for plate bending ; Debongnie, Jean-François Conference (2004, August) This paper presents a procedure for computing approximate solution of bending Kirchhoff plate with an equilibrium finite element model. The accuracy of the equilibrium approach is evaluated through the ... [more ▼] This paper presents a procedure for computing approximate solution of bending Kirchhoff plate with an equilibrium finite element model. The accuracy of the equilibrium approach is evaluated through the concept of error estimator. Especially, a dual analysis by finite elements which leads to lower and upper bounds of the exact solution is presented in numerical examples. [less ▲] Detailed reference viewed: 292 (3 ULg) |
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