Computer science, Informatique, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Informatique; automatique theorique; systemes, Computer science; control theory; systems, Logiciel, Software, Conception assistée, Computer aided design, Faisabilité, Feasibility, Practicabilidad, Fonction potentiel, Potential function, Función potencial, Intégrité, Integrity, Integridad, Méthode raffinement, Refinement method, Método afinamiento, Prototypage rapide, Rapid prototyping, Prototipificación rápida, Protrusion, Protrusión, Subdivision, Subdivisión, 3DU, AFG, DFRP, assembly features, object decomposition, and rapid prototyping

The aim of the work presented in this paper is to enable production of large, complex components on rapid prototyping machines whose build volume is less than the size of the desired component. Such large components can be produced as fabrications if a suitable subdivision can be generated. In general, any component can be subdivided into smaller parts by an array of orthogonal planes, but the resulting shapes could have geometries that are difficult to produce accurately on many rapid prototyping systems. The system presented here creates a decomposition designed for both rapid prototyping and assembly. The proposed method considers potential manufacturing problems, and modifies the boundaries of individual parts, where necessary. Additionally, the system also generates complementary male/female (i.e., matching protrusion/depression) assembly features at the interface between the component parts in order to improve the integrity and assemblability of the final component. To prove the functionality of the system, three components are analyzed at the end of this paper.

Mechanical engineering, Génie mécanique, Sciences exactes et technologie, Exact sciences and technology, Physique, Physics, Domaines classiques de la physique (y compris les applications), Fundamental areas of phenomenology (including applications), Transfert de chaleur, Heat transfer, Méthodes numériques et analytiques, Analytical and numerical techniques, Sciences appliquees, Applied sciences, Genie mecanique. Construction mecanique, Mechanical engineering. Machine design, Généralités, General, Conception assistée, Computer aided design, Concepción asistida, Condition opératoire, Operating conditions, Condición operatoria, Convection, Convección, Epaisseur couche, Layer thickness, Espesor capa, Etude expérimentale, Experimental study, Estudio experimental, Gel, Freeze, Helada, Glace, Ice, Hielo, Gouttelette, Droplet, Gotita, Modélisation, Modeling, Modelización, Méthode élément fini, Finite element method, Método elemento finito, Poteau, Column, Poste, Prototypage rapide, Rapid prototyping, Prototipificación rápida, Solidification, Solidificación, Transfert chaleur, Heat transfer, and Transferencia térmica

Rapid freeze prototyping (RFP) can generate three-dimensional ice patterns from computer-aided design (CAD) models by depositing and solidifying water droplets layer by layer. One important issue of the RFP process is how to fabricate the ice pattern to desired accuracy in an acceptable short time. The waiting time between two successive layers is a critical factor. A waiting time that is too short will lead to unacceptable part accuracy, while a waiting time that is too long will lead to an excessive build time. Finite element analysis is employed in this study to predict the solidification time of a newly deposited water layer and to develop a better understanding of heat transfer during the RFP process. ANSYS Parametric Development Language (APDL) is utilized to develop software for the prediction of solidification time. The result is used to investigate the effect of various process parameters on the solidification time of an ice column and a vertical ice wall. These parameters include environment temperature, heat convection coefficient, initial water droplet temperature, layer thickness, and waiting time between two successive layers. Experiments are conducted and the measured results are shown to agree well with simulation results.

Computer science, Informatique, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Informatique; automatique theorique; systemes, Computer science; control theory; systems, Logiciel, Software, Systèmes informatiques et systèmes répartis. Interface utilisateur, Computer systems and distributed systems. User interface, Genie mecanique. Construction mecanique, Mechanical engineering. Machine design, Généralités, General, Transports terrestres, transports aeriens, transports maritimes, constructions navales, Ground, air and sea transportation, marine construction, Transports et trafic routiers, Road transportation and traffic, Angle inclinaison, Tilt angle, Angulo inclinación, Automobile, Motor car, Automóvil, Basculement, Tilting, Balanceo, Conduite véhicule, Vehicle driving, Conducción vehículo, Eclairage, Lighting, Alumbrado, Feu véhicule, Vehicle light, Fuego vehículo, Identification système, System identification, Identificación sistema, Nuit, Night, Noche, Prototypage rapide, Rapid prototyping, Prototipificación rápida, Réalité virtuelle, Virtual reality, Realidad virtual, Simulateur, Simulator, Simulador, Simulation ordinateur, Computer simulation, Simulación computadora, Système temps réel, Real time system, Sistema tiempo real, Temps réel, Real time, Tiempo real, Visualisation, Visualization, Visualización, aiming distance, dynamic leveling lights, glare, night drive simulation, real-time visualization, virtual prototyping, and virtual reality

This paper proposes to use a virtual reality-based night driving simulator as a tool to evaluate an advanced leveling light system. The night driving simulator visualizes the complex beam patterns of automotive headlights in high detail, while the vehicle motion directly affects the lighting direction of the headlights. The system is connected to the control algorithm of an advanced leveling light system, which controls the headlight tilting angle. Within the virtual prototyping process of the lighting system, good combinations of control parameter values can be identified, based on virtual test drives, and the number of real test drives can be reduced significantly.

Mechanical engineering, Génie mécanique, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Metaux. Metallurgie, Metals. Metallurgy, Assemblage et découpage thermique: aspects métallurgiques, Joining, thermal cutting: metallurgical aspects, Soudage, Welding, Genie mecanique. Construction mecanique, Mechanical engineering. Machine design, Généralités, General, Analyse contrainte, Stress analysis, Análisis tensión, Spannungsanalyse, Elastoplasticité, Elastoplasticity, Elastoplasticidad, Inélasticité, Inelasticity, Inelasticidad, Modèle dynamique, Dynamic model, Modelo dinámico, Modélisation, Modeling, Modelización, Méthode numérique, Numerical method, Método numérico, Méthode élément fini, Finite element method, Método elemento finito, Finite Element Methode, Prototypage rapide, Rapid prototyping, Prototipificación rápida, Soudage par points, Spot welding, Soldadura punto, Soudage ultrason, Ultrasound welding, Soldeo por ultrasonidos, Ultraschallschweissen, Soudage, Welding, Soldadura, Schweissen, Théorie quasi statique, Quasi static theory, and Teoría cuasiestática

Ultrasonic bonding of thin foils has been recently introduced to rapid prototyping of complex-shaped and/or internally structured layered parts. This article provides the mechanical analysis of an elementary ultrasonic spot welding process of a metal foil on a previously deposited substrate. A 2-D, quasi-static/dynamic, elasto-plastic numerical model of the stress/strain field is developed by finite element analysis. Its frictional boundary conditions at the foil/substrate interface are described via a simpler plain stress, static analytical formulation, and identified experimentally by strain measurements on the substrate surface, adjacently to the ultrasonic probe. The calibrated computational simulation is validated in the laboratory and applied in studying the elastic stress concentrations, plastic deformation initiation and propagation patterns, the slippage at the interface surface and the dynamic effects of ultrasonic loading on the bonding process. This mechanical model is suitable for analysis of multi-joint ultrasonic rapid prototyping and its applications in fabrication of multi-material, functional internal structures with embedded components.

Control theory, operational research, Automatique, recherche opérationnelle, Mechanical engineering, Génie mécanique, Mechanics acoustics, Mécanique et acoustique, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Genie mecanique. Construction mecanique, Mechanical engineering. Machine design, Généralités, General, Conception ingénierie, Engineering design, Concepción ingeniería, Déflexion, Deflection, Deflección, Faisabilité, Feasibility, Practicabilidad, Lithographie, Lithography, Litografía, Modèle géométrique, Geometrical model, Modelo geométrico, Moulage injection, Injection molding, Moldeo por inyección, Moule injection, Injection mold, Molde inyección, Outillage rapide, Rapid tooling, Herramienta rapida, Processus conception, Design process, Proceso concepcion, Processus fabrication, Production process, Proceso fabricación, Prototypage rapide, Rapid prototyping, Prototipificación rápida, Préparation gamme fabrication, Process planning, Preparación serie fabricación, Stratification, Estratificación, Stéréolithographie, Stereolithography, and Stereolitografia

The goal of fabricating functional prototypes quickly is hindered by a mismatch of material properties between production materials and those used in rapid prototyping (RP) machines, such as stereolithography. Even when rapid tooling (RT) technologies are utilized for injection molded parts, differences in mold materials cause differences in molded part properties. To compensate for these material and process differences, a design for manufacturing (DFM) method is introduced, called geometric tailoring. The idea is to modify dimensions of prototype parts to match key characteristics of production parts, such as stress and deflection behaviors. For RP parts, the geometric tailoring DFM method integrates two sub-problems, one for achieving functional requirements by matching part behaviors, and one for RP process planning to incorporate manufacturing capabilities and limitations. For parts fabricated by RT, an additional sub-problem is integrated, namely injection molding process planning. Problem decomposition is critical due to the coupled nature of the sub-problems. A problem decomposition and solution procedure is presented. The geometric tailoring method is shown to enable the matching of prototype to production part behaviors, while improving manufacturability.

Control theory, operational research, Automatique, recherche opérationnelle, Mechanical engineering, Génie mécanique, Mechanics acoustics, Mécanique et acoustique, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Genie mecanique. Construction mecanique, Mechanical engineering. Machine design, Généralités, General, Transmissions, Drives, Mécanismes articulés, cames, Linkage mechanisms, cams, Conception machine, Machine design, Concepción máquina, Frittage laser sélectif, Selective laser sintering, Sinterizacion laser selectiva, Mécanisme articulé, Linkage mechanism, Mecanismo articulado, Prototypage rapide, Rapid prototyping, Prototipificación rápida, Stéréolithographie, Stereolithography, and Stereolitografia

In this paper, the application of Rapid Prototyping in fabricating non-assembly robotic systems and mechanisms is presented. Using two Rapid Prototyping techniques, Stereolithography and Selective Laser Sintering, prototypes of mechanical mobile joints were fabricated. The designs of these component joints were then used to fabricate the articulated structure of experimental prototypes for two robotic systems: (1) a three-legged parallel manipulator, (2) a four degree-of-freedom finger of a five-fingered robotic hand. These complex multi-articulated, multi-link, multi-loop systems have been fabricated in one step, without requiring assembly while maintaining their desired mobility. The feasibility and usefulness of Rapid Prototyping as a method for the fabrication of these non-assembly type mechanisms and robotic systems is the focus of this work.

Mechanical engineering, Génie mécanique, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Metaux. Metallurgie, Metals. Metallurgy, Assemblage et découpage thermique: aspects métallurgiques, Joining, thermal cutting: metallurgical aspects, Soudage, Welding, Acier, Steel, Acero, Blindage, Shielding, Blindaje, Boucle réaction, Feedback, Retroalimentación, Etude expérimentale, Experimental study, Estudio experimental, Experimentelle Untersuchung, Fil métallique, Wire, Hilo metálico, Draht, Gouttelette, Droplet, Gotita, Modèle 3 dimensions, Three dimensional model, Modelo 3 dimensiones, Onde sinusoïdale, Sinusoidal wave, Onda sinusoidal, Oscillation forcée, Forced oscillation, Oscilación forzada, Pare choc, Bumpers, Parachoques, Profil profondeur, Depth profile, Perfil profundidad, Tiefenprofil, Profondeur pénétration, Penetration depth, Profundidad penetración, Prototypage rapide, Rapid prototyping, Prototipificación rápida, Rétroaction, Feedback regulation, Retroacción, Soudage arc, Arc welding, Soldadura arco, Lichtbogenschweissen, Soudage gaz, Gas welding, Soldadura con gas, Gasschweissen, Soudage sous gaz fil fusible, GMA welding, Metall Schutzgas Schweissen, Soudure, Weld, Soldadura, Schweissnaht, Transfert chaleur masse, Heat mass transfer, Transferencia calor masa, Vibration, Vibración, and Schwingung

Gas metal arc welding (GMAW) of steel in argon-rich shielding usually features free-metal transfer and short-circuiting metal transfer. Projected spray transfer in one droplet per pulse (ODPP) mode in combination with the droplet detachment feedback control is one of the most effective approaches to guarantee high weld quality. This paper explores new methods for controlling mass and heat transfer based on droplet detachment behavior in rapid prototyping by 3D welding. Three groups of experiments are performed based on the different welding current wave forms, pure square wave, square wave combined with sine wave (combined wave), and pure sine wave. Compared with the pure square wave form, the combined wave form can generate a weld bead with a more narrow and shallow penetration profile (the width and depth are 3.04 mm and 0.22 mm, respectively). When a pure sine wave form is used, the droplet is forced to oscillate once at the wire tip (the oscillation cycle equals the pulse cycle) and then detaches smoothly; the droplet is accompanied by a characteristically harmonious sound. Recorded images show that the droplet in a square or combined wave form can be forced to oscillate twice (the oscillation cycle equals half of the pulsed cycle) before it detaches. Careful selection of parameters is required to generate multiple oscillations for the droplet before it detaches. Photos of a weld cross section reveal that the penetration profile can be greatly improved using a combined wave form. The results achieved are not only effective for mass and heat control in rapid prototyping by 3D welding, but also are beneficial for further investigation of the droplet detachment behavior in GMAW.

Mechanical engineering, Génie mécanique, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Genie mecanique. Construction mecanique, Mechanical engineering. Machine design, Généralités, General, Conception assistée, Computer aided design, Concepción asistida, Etude expérimentale, Experimental study, Estudio experimental, Gel, Freeze, Helada, Glace, Ice, Hielo, Modélisation, Modeling, Modelización, Prototypage rapide, Rapid prototyping, Prototipificación rápida, Réponse transitoire, Transient response, Respuesta transitoria, Solidification, Solidificación, Transfert chaleur, Heat transfer, and Transferencia térmica

Rapid Freeze Prototyping (RFP) builds ice parts by depositing and freezing water in a layer-by-layer manner This paper presents a one-dimensional transient heat transfer model for a thin ice wall built by the RFP process. Closed-form solutions for temperatures of the ice wall during solidification of a layer of water are derived, which can be used to estimate the solidification time. Natural cooling of the ice wall after solidification of a water layer is also studied. The analytical solutions of heating and cooling of the ice wall agree well with both numerical and experimental results.

Mechanical engineering, Génie mécanique, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Genie mecanique. Construction mecanique, Mechanical engineering. Machine design, Généralités, General, Angle contact, Contact angle, Angulo contacto, Conception assistée, Computer aided design, Concepción asistida, Eau, Water, Agua, Etude expérimentale, Experimental study, Estudio experimental, Gel, Freeze, Helada, Glace, Ice, Hielo, Gouttelette, Droplet, Gotita, Gravité, Gravity, Gravedad, Modèle 3 dimensions, Three dimensional model, Modelo 3 dimensiones, Modélisation, Modeling, Modelización, Prototypage rapide, Rapid prototyping, Prototipificación rápida, Rugosité, Roughness, Rugosidad, Stratification, Estratificación, Surface rugueuse, Rough surface, Superficie rugosa, Tension superficielle, Surface tension, and Tensión superficial

Rapid Freeze Prototyping (RFP) builds three-dimensional ice parts according to CAD models by depositing and freezing water droplets in a layer-by-layer manner. This paper studies the layer thickness and surface roughness of ice parts built by the RFP process. The equations governing the water line formed by a sequence of water droplets are developed, and then a model of the water line is proposed by simplifying these equations based on our experimental condition. The analysis using this model shows that the cross-section of an ice line is circular, which is verified by experimental observations. Based on the analysis, equations for predicting layer thickness as a function of nozzle scanning speed, water feed rate, and water-ice contact angle in building vertical and slant walls by the RFP are derived and the predictions from these equations are shown to agree well with experimental measurements. The surface roughness of ice parts built by the RFP process is also studied.

Mechanical engineering, Génie mécanique, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Genie mecanique. Construction mecanique, Mechanical engineering. Machine design, Généralités, General, Sciences biologiques et medicales, Biological and medical sciences, Sciences medicales, Medical sciences, Chirurgie (generalites). Transplantations, greffes d'organes et de tissus. Pathologie des greffons, Surgery (general aspects). Transplantations, organ and tissue grafts. Graft diseases, Technologie. Biomatériaux. Equipements, Technology. Biomaterials. Equipments, Application médicale, Medical application, Aplicación medical, Chirurgie, Surgery, Cirugía, Conception assistée, Computer aided design, Concepción asistida, Prototypage rapide, Rapid prototyping, Prototipificación rápida, Radiographie RX, X ray radiography, and Radiografía RX

Advances in rapid prototyping give the technology new roles in medical treatments.

Mechanical engineering, Génie mécanique, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Genie mecanique. Construction mecanique, Mechanical engineering. Machine design, Généralités, General, Correction erreur, Error correction, Corrección error, Etude expérimentale, Experimental study, Estudio experimental, Forme géométrique, Geometrical shape, Forma geométrica, Forme libre, Free form, Forma libre, Géométrie solide, Solid geometry, Geometría sólidos, Prototypage rapide, and Rapid prototyping

A generic closed-loop strategy for error compensation is presented which extracts and mathematically models the geometry of sculptured artifacts, and compensates for cumulative error build-up during replication. Experimental results using this strategy demonstrate that a considerable improvement in the accuracy of the end product can be achieved. The replication process involves scanning, CAD solid model creation, rapid prototyping utilizing the stereolithography process, the production of room temperature vulcanized (RTV) molds, the casting of polyurethane parts from the RTV mold, abrasive finishing processes associated with these prototyping processes, and the CNC machining of production molds and dies. At each stage in the replication process, the surface errors (caused primarily by material shrinkage, layer curling, internal stresses, chemical curing phenomena, and material removal during mechanical surface finishing) are tracked and used in subsequent production, through an iterative process of surface fitting and surface compensation.

Mechanical engineering, Génie mécanique, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Genie mecanique. Construction mecanique, Mechanical engineering. Machine design, Généralités, General, Etude expérimentale, Experimental study, Estudio experimental, Forme libre, Free form, Forma libre, Gel, Freeze, Helada, Glace, Ice, Hielo, Microusinage, Micromachining, Micromaquinado, Modélisation, Modeling, Modelización, Motivation, Motivación, Prototypage rapide, Rapid prototyping, and Prototipificación rápida

Rapid freeze prototyping is a solid freeform fabrication method that uses water freezing into ice as the build material. Each layer of geometry is deposited and allowed to freeze before the next layer is added in order to additively create a three-dimensional ice part. A sacrificial support material is needed for the fabrication of complex ice parts. Identifying a suitable support material and understanding the interaction between the build and support materials is the motivation behind this study. A temperature prediction model and a concentration prediction model are presented. Experimental results have been obtained to validate these models.

Mechanical engineering, Génie mécanique, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Genie mecanique. Construction mecanique, Mechanical engineering. Machine design, Généralités, General, Article synthèse, Review, Artículo síntesis, Conception assistée, Computer aided design, Concepción asistida, Etat actuel, State of the art, Estado actual, Forme libre, Free form, Forma libre, Productique, Computer integrated manufacturing, Robótica, Prototypage rapide, Rapid prototyping, and Prototipificación rápida

This article will give a brief review of the start-of-the-art in commercial practice and advanced research in the field of Rapid Prototyping with special attention to the additive methods of Solid Free Form Fabrication. Recent applications of this technology in computer integrated manufacturing environments will be outlined. Future applications and research in new materials will also be addressed.

Mechanical engineering, Génie mécanique, Mechanics acoustics, Mécanique et acoustique, Sciences exactes et technologie, Exact sciences and technology, Physique, Physics, Domaines classiques de la physique (y compris les applications), Fundamental areas of phenomenology (including applications), Mécanique des fluides, Fluid dynamics, Théorie générale, General theory, Sciences appliquees, Applied sciences, Genie mecanique. Construction mecanique, Mechanical engineering. Machine design, Généralités, General, Analyse conceptuelle, Conceptual analysis, Análisis conceptual, Argile, Clay, Arcilla, Conception assistée, Computer aided design, Concepción asistida, Conception ingénierie, Engineering design, Concepción ingeniería, Géométrie solide, Solid geometry, Geometría sólidos, Modèle géométrique, Geometrical model, Modelo geométrico, Mécanique fluide numérique, Computational fluid dynamics, Mecánica fluido numérica, Prototypage rapide, Rapid prototyping, Prototipificación rápida, Refroidissement, Cooling, Enfriamiento, Réalité virtuelle, Virtual reality, Realidad virtual, Turbine, Turbina, Turbomachine, and Turbomáquina

Computational fluid dynamics has become a mature art form and its use in turbomachinery design has become commonplace. Simple blade-blade simulations run at near interactive rates but anything involving complex geometry-such as turbine cooling-turns around too slowly to participate in realistic design cycles; this is mostly due to the difficulty of modifying and meshing the geometry. Simulations for complex geometries are run afterwards as a check-rather than at the critical conceptual design phase. There is a clear opportunity for some sort of rapid prototyping but fully 3D simulation to remedy this. This paper reports work exploring the relationship between solid modeling, mesh generating, and flow solving in the general context of design optimization but with the emphasis on rapid prototyping. In particular, the work is interested in the opportunities derived by tightly integrating these traditionally separate activities together within one piece of software. The near term aim is to ask the question: how might a truly virtual, rapid prototyping design system, with a tactile response such as sculpting in clay, be constructed? This paper reports the building blocks supporting that ambition.

Computer science, Informatique, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Informatique; automatique theorique; systemes, Computer science; control theory; systems, Logiciel, Software, Systèmes informatiques et systèmes répartis. Interface utilisateur, Computer systems and distributed systems. User interface, Simulation, Génie logiciel, Software engineering, Assurance qualité, Quality assurance, Aseguración calidad, Automate, Automaton, Autómata, Calcul réparti, Distributed computing, Cálculo repartido, Commande automatique, Automatic control, Control automático, Commande mécanique, Mechanical control, Mando mecánico, Commande électronique, Electronic control, Control electrónico, Construction mécanique, Mechanical engineering, Construcción mecánica, Efficacité, Efficiency, Eficacia, Modèle comportement, Behavior model, Modelo comportamiento, Modèle géométrique, Geometrical model, Modelo geométrico, Modélisation, Modeling, Modelización, Multidisciplinaire, Multidisciplinary, Multidisciplinar, Mécatronique, Mechatronics, Mecatrónica, Méthode descendante, Top down method, Método descendente, Processus conception, Design process, Proceso concepcion, Réalité virtuelle, Virtual reality, Realidad virtual, Simulateur, Simulator, Simulador, Simulation ordinateur, Computer simulation, Simulación computadora, Système dynamique, Dynamical system, Sistema dinámico, Système hybride, Hybrid system, Sistema híbrido, Temps réel, Real time, Tiempo real, Architecture logiciel, Software architecture, and Arquitectura logicial

Mechatronics is the integration of different sciences and techniques of mechanical engineering, automatic control, electronics, and informatics. The rapid evolution of the market competitors requires the reduction of development time of a product while increasing the quality and performance. It is, therefore, necessary to increase the efficiency of the design process. To meet this need, simulation and, especially, virtual prototyping have become a key technology. It is difficult to find simulation tools are able to analyze multidependent systems of different areas. However, an environment that allows a simulation integrating multidisciplinary mechatronic systems is necessary. This paper describes a method of design and simulation of mechatronic systems. First, we identify the behavior model and its associated 3D geometric model. The behavior model is seen as a dynamic hybrid system of two coupled hybrid automata (operative part and control part). Then, we present OpenMASK and OpenModelica simulators, the IEEE1516 standard HLA and work related to this distributed architecture for simulation. In a top-down approach, we present our method and experiments to integrate HLA functionalities in these simulators and to distribute the modeling elements of mechatronic systems. Also, we propose extensions to integrate real-time for interactive simulations. Finally, we apply our approach on a representative example of a mechatronic system.

Control theory, operational research, Automatique, recherche opérationnelle, Mechanical engineering, Génie mécanique, Mechanics acoustics, Mécanique et acoustique, Sciences exactes et technologie, Exact sciences and technology, Physique, Physics, Domaines classiques de la physique (y compris les applications), Fundamental areas of phenomenology (including applications), Mécanique des solides, Solid mechanics, Dynamique des solides (balistique, collision, système n corps, stabilisation...), Solid dynamics (ballistics, collision, multibody system, stabilization...), Sciences appliquees, Applied sciences, Genie mecanique. Construction mecanique, Mechanical engineering. Machine design, Transmissions, Drives, Mécanismes articulés, cames, Linkage mechanisms, cams, Angle rotation, Rotation angle, Angulo rotación, Cinématique, Kinematics, Cinemática, Domaine travail, Workspace, Dominio trabajo, Découplage, Decoupling, Desacoplamiento, Entrée sortie, Input output, Entrada salida, Equation quadratique, Quadratic equation, Ecuación segundo grado, Manipulateur, Manipulator, Manipulador, Modélisation, Modeling, Modelización, Mécanisme articulé, Linkage mechanism, Mecanismo articulado, Mécanisme parallèle, Parallel mechanism, Mecanismo paralelo, Problème direct, Direct problem, Problema directo, Singularité, Singularity, Singularidad, Système 4 degré liberté, System with two degrees of freedom, Sistema 4 grados libertad, 4-DOF manipulator, SCARA motion, Schönflies motion, kinematic decoupling, parallel manipulator, and singularities

A four-decree-of-freedom (DOF) 3T1R parallel manipulator is presented in this paper. This manipulator generates the family of so-called Schönflies motions, SCARA motions or 3T1R motions, in which the moving platform can translate in all directions and rotate around an axis of a fixed direction. The kinematic analysis of this architecture is presented, including the study of the constraint singular configurations, kinematic singular configurations, and the determination of the workspace. A prototype (the Quadrupteron) is also presented and demonstrated. The characteristics of the proposed prototype are (a) there is no constraint singularity, (b) its input-output equations are partially decoupled, (c) its kinematic singular configurations can be expressed using, an equation in the angle of rotation of the moving platform and are thus easy to avoid at the design stage, and (d) its forward displacement analysis requires the solution of a univariate quadratic equation and can therefore be solved efficiently.

Mechanical engineering, Génie mécanique, Sciences exactes et technologie, Exact sciences and technology, Physique, Physics, Generalites, General, Méthodes mathématiques en physique, Mathematical methods in physics, Techniques de calcul, Computational techniques, Méthodes des éléments finis et méthode de galerkin, Finite-element and galerkin methods, Sciences appliquees, Applied sciences, Informatique; automatique theorique; systemes, Computer science; control theory; systems, Logiciel, Software, Conception assistée, Computer aided design, Genie mecanique. Construction mecanique, Mechanical engineering. Machine design, Généralités, Finite-element and Galerkin methods, Conception assistée, Computer aided design, Concepción asistida, Faisabilité, Feasibility, Practicabilidad, Génération automatique maille, Automatic mesh generation, Generación automática red, Génération maille, Mesh generation, Géométrie solide, Solid geometry, Geometría sólidos, Modèle 3 dimensions, Three dimensional model, Modelo 3 dimensiones, Modèle géométrique, Geometrical model, Modelo geométrico, Méthode numérique, Numerical method, Método numérico, Méthode élément fini, Finite element method, Método elemento finito, Prototype, Prototipo, Réalité virtuelle, Virtual reality, and Realidad virtual

Manufacturability analysis of product design reduces the downstream problems of manufacturing. Such design approaches are referred to as Virtual Prototyping when performed on the computer. In the present research, Virtual Prototyping is facilitated by the use of an automated method of determining the finite element meshes needed to perform finite element analyses. Finite element analysis requires a finite element mesh of the product model as input. This mesh (an approximation of an object's geometry and topology, composed in terms of a given individual unit, e.g., a tetrahedron, or a hexahedron ), can be generated using a variety of methods. The research presented here offers an approach for automatic mesh generation that addresses some of the limitations in the mesh-generation technologies currently available. This article presents an approach for automatically generating hexahedral meshes from solid models. The mesh generating method presented in this paper involves four major steps. First, objects called Basic LOgical Bulk shapes (BLOBs) are determined from the solid model of a given part. Second, these BLOBs are used to decompose the solid model into its various sub-volumes, Third, a multiple-block structure (MBS). ). which is a group of hexahedral objects, is constructed to approximate the solid model. Finally, transfinite mapping is employed to project the faces of the MBS onto the surfaces of a model to generate the finite element meshes.

Control theory, operational research, Automatique, recherche opérationnelle, Mechanical engineering, Génie mécanique, Mechanics acoustics, Mécanique et acoustique, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Genie mecanique. Construction mecanique, Mechanical engineering. Machine design, Transmissions, Drives, Mécanismes articulés, cames, Linkage mechanisms, cams, Contrôle vibration, Vibration control, Control vibración, Equilibrage, Balancing, Equilibrado, Inertie, Inertia, Inercia, Jambe, Leg, Pierna, Mécanisme 5 barres, Five bar mechanism, Mecanismo 5 barras, Mécanisme articulé, Linkage mechanism, Mecanismo articulado, Mécanisme parallèle, Parallel mechanism, Mecanismo paralelo, Mécanisme réaction, Reaction mechanism, Mecanismo reacción, Optimisation, Optimization, Optimización, Système 3 degrés liberté, System with three degrees of freedom, and Sistema 3 grados libertad

This paper addresses the dynamic balancing of a planar three-degree-of-freedom parallel mechanism. A mechanism is said to be dynamically balanced if for any motion of the mechanism, the reaction forces and torques at the base are identically equal to zero, at all times. The proposed mechanism is based on legs consisting of five-bar parallelogram linkages. The balancing equations are first obtained. Then, optimization is used in order to minimize the mass and inertia of the moving links. Finally, a numerical verification of the dynamic balancing is provided and the prototype is presented.

Control theory, operational research, Automatique, recherche opérationnelle, Mechanical engineering, Génie mécanique, Mechanics acoustics, Mécanique et acoustique, Sciences exactes et technologie, Exact sciences and technology, Physique, Physics, Generalites, General, Instruments, appareillage, composants et techniques communs à plusieurs branches de la physique et de l'astronomie, Instruments, apparatus, components and techniques common to several branches of physics and astronomy, Techniques et équipements généraux, General equipment and techniques, Transducteurs, Transducers, Actionneur, Actuators, Alliage mémoire forme, Shape memory alloy, Aleación memoria forma, Corps creux, Hollow body, Cuerpo hueco, Essai compression, Compressive testing, Etude expérimentale, Experimental study, Forme hélicoïdale, Helical shape, Forma helicoidal, Largeur bande, Bandwidth, Modélisation, Modelling, Poutre paroi mince, Thin walled beam, Viga pared delgada, Propriété thermomécanique, Thermomechanical properties, Propriedad termomecánica, Refroidissement, Cooling, Ressort hélicoïdal, Coil spring, Muelle helicoidal, Système masse ressort, Spring mass system, Sistema masa muelle, shape memory alloys, spring design, and thermomechanical characterization

Shape memory alloys (SMAs) are used in many applications as actuators. The main drawbacks that limit the use of the SMAs in the field of mechanical actuation are the low mechanical bandwidth (up to a few Hertzs) and the unsatisfactory stroke (several millimeters). This paper contributes to enhancing the performances of SMA actuators by proposing a new SMA helical spring with a hollow section. The hollow spring is modeled, then it is constructed, and finally it is tested in compression to compare its performances with those of a spring with a solid cross section of equal stiffness and strength. Emptied of the inefficient material from its center, the hollow spring features a lower mass (37% less) and an extremely lower cooling time (four times less) than its solid counterpart. These results demonstrate that helical springs with a hollow construction can be successfully exploited to build SMA actuators for higher operating frequencies and improved strokes.

Control theory, operational research, Automatique, recherche opérationnelle, Mechanical engineering, Génie mécanique, Mechanics acoustics, Mécanique et acoustique, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Genie mecanique. Construction mecanique, Mechanical engineering. Machine design, Conception industrielle, planification, organisation, sécurité, Industrial design, planning, organization, safety, Assistance ordinateur, Computer aid, Asistencia ordenador, Conception ingéniérie, Engineering design, Concepción ingeniería, Exemple, Example, Ejemplo, Image virtuelle, Virtual image, Imagen virtual, Prototype, Prototipo, Simulation système, System simulation, Simulación sistema, Système mécanique, Mechanical system, Sistema mecánico, Véhicule, Vehicle, and Vehículo

Developments in simulation technology that enable a qualitatively new virtual prototyping approach to design of mechanical systems are summarized and their integration into an engineering design environment is illustrated. Simulation tools and their enabling technologies are presented in the context of vehicle design, with references to the literature provided. Their implementation for design representation, real-time driver-in-the-loop simulation, dynamic performance simulation, dynamic stress and life prediction, maintainability analysis, design sensitivity analysis, and design optimization is outlined. A testbed comprised of computer aided engineering tools and a design level of fidelity driving simulator that has been developed to demonstrate the feasibility of virtual prototyping simulation for mechanical system design is presented. Two 1994 demonstrations of this capability for vehicle design are presented, to illustrate the state of the technology and to identify challenges that remain in making virtual prototyping simulation an integral part of mechanical system design in US industry.