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Investigating the performance of model order reduction techniques for nonlinear radiative heat transfer problems ; Masset, Luc ; Kerschen, Gaëtan et al in Proceedings of the International Conference on Advanced Computational Methods in Engineering (2011) The problem of nonlinear radiative heat transfer is one of great importance to the aerospace industry. However, analysing large-scale, nonlinear, multiphysical, dynamical structures, by using mathematical ... [more ▼] The problem of nonlinear radiative heat transfer is one of great importance to the aerospace industry. However, analysing large-scale, nonlinear, multiphysical, dynamical structures, by using mathematical modelling and simulation, e.g. Finite Element Modelling (FEM), can be computationally expensive. This provides motivation for the development of Model-Order Reduction (MOR) techniques capable of reducing simulation times without the loss of important information. The objective is to demonstrate the method of Proper Orthogonal Decompostition (POD) as a technique for nonlinear MOR. The nonlinear radiative exchanges between a linear benchmark beam within an external box (Figure 1) are analysed and a reduction procedure for this fully coupled, nonlinear, multiphysical, thermomechanical system is established. The solution to the strongly coupled, thermomechanical equations of motion is found by making use of an extended version of the implicit generalized-alpha scheme. In the reduced model, the residual of the unreduced system of equations need to be evaluated at each Newton iteration of each time step. In order to optimise the efficiency of the reduction method it is shown that the internal forces can be split into their linear and nonlinear counterparts. Only the nonlinear terms change at each time step, thus only these terms need to remain in the iterative loop significantly reducing the number of parameters that are to be computed at each step. These efficiency improvements to the method are discussed and the results are given. [less ▲] Detailed reference viewed: 48 (6 ULg)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: 110 (17 ULg)Una proyección sintética para el diseño arquitectónico con la luz del sol ; Masset, Luc ; Beckers, Pierre Conference (2007, October) Detailed reference viewed: 122 (17 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: 116 (5 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: 148 (10 ULg)Machining processes simulation : specific finite element aspects Masset, Luc ; Debongnie, Jean-François in Journal of Computational & Applied Mathematics (2004, July 01), 168(1-2), 309-320 The paper presents a simulation tool designed to predict form errors of part surfaces obtained by face milling and turning processes. For these operations, the form error is often due to the flexibility ... [more ▼] The paper presents a simulation tool designed to predict form errors of part surfaces obtained by face milling and turning processes. For these operations, the form error is often due to the flexibility of the workpiece and its supports. The finite element method is adopted to model the part geometry and to compute its deformations. Numerous load cases are required to obtain the form error so that classical resolution methods prove to be inefficient (CPU time, memory and disk space). The paper mainly focuses on the special computation scheme adopted in order to improve the resolution of such an atypical problem. [less ▲] Detailed reference viewed: 93 (31 ULg)Chatter maps for process design of powertrain components Masset, Luc ; Debongnie, Jean-François ; in Moisan, Alphonse; Poulachon, Gérard (Eds.) Proceedings of the 7th CIRP International Workshop on Modeling of Machining Operations (2004, May) During rough machining operations of powertrain components, chatter vibrations may occur on the edges of flexible structures. This paper presents a numerical method, based on the finite element method and ... [more ▼] During rough machining operations of powertrain components, chatter vibrations may occur on the edges of flexible structures. This paper presents a numerical method, based on the finite element method and Tlusty's theory, which gives a chatter map of the machined surface. Each map point represents the greatest depth of cut leading to unconditionally stable cut. Each value depends on the structural damping, the cutting stiffness and the local static stiffness, which is computed using conventional linear elastic FEA. Chatter maps offer a convenient and effective decision support system for robust process design. As a case study, the rough milling operation of a crankcase deck face with a two-stage cutter is presented. [less ▲] Detailed reference viewed: 74 (3 ULg)Solving problems with contact in machining process simulation Masset, Luc ; Debongnie, Jean-François ; in Brucato, Valerio (Ed.) Proceedings of the 6th International ESAFORM Conference on Material Forming (2003, April) At the 2001 Esaform conference, we have presented a simulation tool designed to predict form errors of part surfaces obtained by face milling and turning processes. The most relevant aspect of the ... [more ▼] At the 2001 Esaform conference, we have presented a simulation tool designed to predict form errors of part surfaces obtained by face milling and turning processes. The most relevant aspect of the developed method is its ability to solve industrial cases with huge 3D finite element meshes in a very small time. Until recently, we were only considering pure linear problems. However, the simulation of several machining operations requires the introduction of contact. The present paper describes the numerical method developed to solve such non linear problems. [less ▲] Detailed reference viewed: 206 (7 ULg)Fonctionnement et performances des couloirs oscillants à glissement Debongnie, Jean-François ; Masset, Luc in European Journal of Mechanical and Environmental Engineering (2001), 46(4), 243-254 This paper is devoted to the study of the efficiency of an oscillating trough for any value of the frequency. It is found that pure slipping or mixed cycles may occur, the latter comprising sticking ... [more ▼] This paper is devoted to the study of the efficiency of an oscillating trough for any value of the frequency. It is found that pure slipping or mixed cycles may occur, the latter comprising sticking periods. The results of the present analysis concern the cyclic displacement, the mean velocity and the dissipated power. [less ▲] Detailed reference viewed: 40 (5 ULg)Face milling and turning simulation with the finite element method Masset, Luc ; Debongnie, Jean-François ; Beckers, Pierre in Habraken, Anne (Ed.) Proceedings of the 4th International ESAFORM Conference on Material Forming (2001, April) The paper describes a new simulation tool that gives the machined surface error in face milling and turning. The form error component due to the workpiece flexibility is computed using Samcef finite ... [more ▼] The paper describes a new simulation tool that gives the machined surface error in face milling and turning. The form error component due to the workpiece flexibility is computed using Samcef finite element code. The finite element analyses are very efficient on industrial applications thanks to the superelement method. Results are obtained in a short time which makes possible a wide range of simulations such as finding the best tool trajectory, testing several tools and cutting conditions and choosing the most suited fixture design. [less ▲] Detailed reference viewed: 162 (6 ULg)Controlling form errors from 3D measures Debongnie, Jean-François ; Masset, Luc in ASME (Ed.) Proceedings of the 1999 ASME Design Engineering Technical Conference (1999, September) Owing to the fact that a correct evaluation of form errors is particularly difficult by the classical ways, it seems more efficient to develop numerical algorithms from 3D measures. Several methods are ... [more ▼] Owing to the fact that a correct evaluation of form errors is particularly difficult by the classical ways, it seems more efficient to develop numerical algorithms from 3D measures. Several methods are described, including direct and iterative ones. A new method is proposed, which is based on Lp-norms and a specialized algorithm. It proved to be the most effective and robust one on every studied application. [less ▲] Detailed reference viewed: 24 (4 ULg)A model for the prediction of form errors in face milling and turning Masset, Luc ; Debongnie, Jean-François ; et al in ASME (Ed.) Proceedings of he 1999 ASME Design Engineering Technical Conferences (1999, September) A method is proposed for predicting form errors due to both clamping and cutting forces in face milling and turning. It allows complex tool trajectories and workpiece geometries. Error computation is ... [more ▼] A method is proposed for predicting form errors due to both clamping and cutting forces in face milling and turning. It allows complex tool trajectories and workpiece geometries. Error computation is performed by the finite element method. An experimental validation of the model for face milling is presented. Two industrial applications are produced in order to demonstrate the capabilities of the method. [less ▲] Detailed reference viewed: 61 (6 ULg)Simulation de l'usinage : essais de fraisage Masset, Luc ; Debongnie, Jean-François Report (1998) This report describe milling tests which have been done and their comparison to computational results. In order to obtain significant form defects, a very flexible work has been used. Difficulties arose ... [more ▼] This report describe milling tests which have been done and their comparison to computational results. In order to obtain significant form defects, a very flexible work has been used. Difficulties arose in the primary machining of the workpiece, due to residual stresses. A more efficient machining scheme has then be defined for this step. In order to avoid complications coming from the multiplicity of the teeth of the milling tool, fly-dressing has been considered. The results are discussed in detail. [less ▲] Detailed reference viewed: 136 (4 ULg)Sur l'évaluation des défauts de forme à partir de mesures tridimensionnelles Debongnie, Jean-François ; Masset, Luc in European Journal of Mechanical and Environmental Engineering (1998), 43(1), 13-21 Owing to the fact that a correct evaluation of form errors is particularly difficult by the classical ways, it seems more efficient to develop numerical algorithms from 3D measures. Several methods are ... [more ▼] Owing to the fact that a correct evaluation of form errors is particularly difficult by the classical ways, it seems more efficient to develop numerical algorithms from 3D measures. Several methods are described, including direct and iterative ones. A new method is proposed, which is based on Lp-norms and a specialized algorithm. It proved to be the most effective and robust one in every studied application. Another problem which is seldom studied, concerns the sensibility of form errors to measure errors. A theory is presented which leads to a very simple result. [less ▲] Detailed reference viewed: 78 (7 ULg)Modélisation du bridage Beckers, Pierre ; Debongnie, Jean-François ; et al Report (1996) This report is devoted to the modelling of the clamping devices in the projected machining simulation tool Detailed reference viewed: 59 (4 ULg)catalogue des cas-tests Beckers, Pierre ; Debongnie, Jean-François ; et al Report (1996) This report describes the benchmarks which have been done with the machining simulation prototype. Detailed reference viewed: 35 (3 ULg)Comparaisons calculs-essais pour le palier de suspension J64 Beckers, Pierre ; Debongnie, Jean-François ; Masset, Luc Report (1996) This report is devoted to the J64 suspension bearing benchmark. Unfortunately, the actual machining led to considerable vibrations, rendering any comparison impossible. Detailed reference viewed: 25 (3 ULg)Comparaisons calculs-essais pour le carter d'alimentation d'huile TA96 Beckers, Pierre ; Debongnie, Jean-François ; Masset, Luc Report (1996) On this application, the computed results were in the opposite direction as compared to the physical tests. A sound analysis led to the result that a parasitic deformation was due to clamping deformations ... [more ▼] On this application, the computed results were in the opposite direction as compared to the physical tests. A sound analysis led to the result that a parasitic deformation was due to clamping deformations. In fact, the three supports of the work were found to be unsufficiently coplanar. [less ▲] Detailed reference viewed: 31 (4 ULg)Comparaisons calculs-essais pour l'éprouvette cylindrique Beckers, Pierre ; Debongnie, Jean-François ; Masset, Luc Report (1996) In this first application of the machining simulation tool prototype, great difficulties were encountered in the interpretaion of the physical test. In fact, parasitic deformations occured, with a three ... [more ▼] In this first application of the machining simulation tool prototype, great difficulties were encountered in the interpretaion of the physical test. In fact, parasitic deformations occured, with a three-lobed form. This implied the necessity of filtering the experimental data and a physical interpretation of the undue deformation. A theoretical study is performed, leading to the result that this phenomenon is due to the combined effect of the clearance of the clamping jaws and the pre-stress of the dead center. [less ▲] Detailed reference viewed: 34 (3 ULg) |
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