The Experts below are selected from a list of 276 Experts worldwide ranked by ideXlab platform
Miguel Ángel Sebastián - One of the best experts on this subject based on the ideXlab platform.
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Analysis of plate drawing processes by the Upper Bound Method using theoretical work-hardening materials
The International Journal of Advanced Manufacturing Technology, 2009Co-Authors: Eva María Rubio, M. Marín, R. Domingo, Miguel Ángel SebastiánAbstract:The present paper analyses the plate drawing processes carried out in converging dies using theoretical work-hardening materials. The analysis has been carried out by the Upper Bound Method (UBM), modelling the plastic deformation zone by triangular rigid zones (TRZ) and considering that the processes occur under plane strain and partial friction conditions. Explicit expressions for the calculation of the necessary power and the non-dimensional total energy to carry out the process using theoretical work-hardening materials have been established. The results have been compared with those obtained using rigid-perfectly plastic materials. In spite of the fact that the energy involved in the process using a work-hardening material is higher than when a rigid-perfectly plastic material is used, the number of possible sets of variables ( die geometries , cross-sectional area reductions and partial friction coefficients ) increases, since the stability limit of the process increases as well.
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analysis of the energy vanished by friction in tube drawing processes with a fixed conical inner plug by the Upper Bound Method
Materials and Manufacturing Processes, 2008Co-Authors: E Rubio, M. Marcos, Ana Maria Camacho, Miguel Ángel SebastiánAbstract:In this work, an analysis of the energy vanished by friction of thin-walled tube drawing processes in conical converging dies with a fixed conical inner plug has been conducted. The Method used for analysis is the Upper Bound Method (UBM), and the plastic deformation zone has been modelled by three triangular rigid zones (TRZ). The tube inner diameter is considered constant during the process, and therefore, a state of plane strain can be assumed. In addition, the existent friction between the external surface of the tube and the die (material-die), as well as that between the inner surface of the tube and the plug (material-plug) has been modeled by Coulomb friction (μ1 and μ2, respectively). Some significant findings emerged from this study are: the establishment of explicit expressions for evaluating the non-dimensional energy vanished by friction in the die and in the plug, the ability to select the plug that enables the process to be performed with a lower requirement of energy under defined conditio...
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Energetic analysis of tube drawing processes with fixed plug by Upper Bound Method
Journal of Materials Processing Technology, 2006Co-Authors: Eva María Rubio, Cristina Carretero González, M. Marcos, Miguel Ángel SebastiánAbstract:Abstract In this work, an energetic analysis of thin-walled tube drawing processes in conical converging dies with inner plugs has been made. The Method used in the analysis is the Upper Bound Method (UBM). The plastic deformation zone has been modelled by triangular rigid zones (TRZ), with the assumption that the process occurs under plane strain and Coulomb friction conditions.
Sanz A Lobera - One of the best experts on this subject based on the ideXlab platform.
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mechanical solutions for drawing processes under plane strain conditions by the Upper Bound Method
Journal of Materials Processing Technology, 2003Co-Authors: E Rubio M Alvir, M Sebastian A Perez, Sanz A LoberaAbstract:Abstract Present work applies the Limit Analysis Method to the study of drawing processes of solid components associated to plane strain hypothesis. Against the traditional approach to the problem with only one triangular rigid zone, multiblock models are tried. This allows the compared study of different geometries and velocities ranges compatible with the process Boundary conditions, that appear in each case as well as the development of improved solutions for each situation. Finally, some results are presented according to the main mechanical parameters of the process (die semiangle, friction coefficient m or μ and section reduction r ), and the resulting values are discussed.
Jae-chan Choi - One of the best experts on this subject based on the ideXlab platform.
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an Upper Bound analysis of the closed die forging of spur gears
Journal of Materials Processing Technology, 1997Co-Authors: Haeyong Cho, Jaecha Choi, Young Bum Choi, Jae-chan ChoiAbstract:Abstract Closed-die forging of spur gears of which the shape of the fillet is a straight line in the radial direction is investigated by means of the Upper-Bound Method. A kinematically admissible velocity field has been newly proposed in this paper: specifically an involute curve has been introduced to represent the tooth profile of the forging die. It was assumed that a constant frictional stress is applied on the contacting surfaces. Utilizing the formulated velocity field, numerical calculations has been carried out to investigate the effects of varying various parameters, such as modules, numbers of teeth and friction factors, on the forging of the spur gears. It was found that forging load or average relative pressure was dependent predominantly on the number of teeth.
Hunghsiou Hsu - One of the best experts on this subject based on the ideXlab platform.
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a study on precision forging of spur gear forms and spline by the Upper Bound Method
International Journal of Mechanical Sciences, 2002Co-Authors: Hunghsiou HsuAbstract:Abstract Precision forging is an important manufacturing procedure of spline and spur gear forms. It has advantages of improved strength, good tolerance, saving billet material, dispensing with the cutting, etc. In this paper, a mathematical model using an Upper Bound Method is proposed for forging of spur gear forms and spline to investigate the plastic deformation behavior of billet within the die cavity. The material of solid billet was assumed as rigid–plastic and the shape of the tooth profile was accounted for the mathematical modeling of the kinematically admissible velocity field assumed for the plastic zone. The non-uniform velocity was employed for simulating the inhomogeneous deformation and the effect of barreling during the forging. Using the present model, various effects of forming parameter such as the friction factor, reduction, number of teeth, etc. upon the non-dimensional forging pressure, forging force and barreling of the spur gear forms and spline were analyzed systematically and the results compared with those of other researcher's analytical and experimental work. It is shown that the present modeling of the process improves knowledge of the process design performance for the precision forging of spur gear form and spline.
Massoud Malaki - One of the best experts on this subject based on the ideXlab platform.
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Investigation of the Bimetal Clad Drawing by Upper Bound Method
Journal of Materials Engineering and Performance, 2013Co-Authors: Massoud Malaki, Hamid Maleki, Hamid Reza RoohaniAbstract:In this research, a mathematical model for the cold drawing of bilayered strip is presented by the Upper Bound Method. In terms of effective process parameters such as drawing power, drawing force, layer reductions, and bonding strength of the bimetal strip, the effect of total relative thickness reduction has been investigated using the Upper Bound theorem. Also, bonding strength is calculated using the Method. In order to verify the theoretical model, a series of experiments on bilayer strip drawing are implemented by aluminum and mild steel material strips. Through the study, it can clearly been concluded that the presented analytical approach is applicable for simulating and estimating the cold drawing process of the bilayer sheets and it is able to offer a good knowledge through producing the bimetal sheets.
