The Experts below are selected from a list of 153 Experts worldwide ranked by ideXlab platform
Hans Keife - One of the best experts on this subject based on the ideXlab platform.
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Cylindrical Mandrel drawing of tubes a matrix method simulation compared with experiment
Journal of Materials Processing Technology, 1992Co-Authors: Stanislaw Urbanski, Marek Packo, Ulf Stahlberg, Hans KeifeAbstract:Abstract The demand from industry for metal-forming simulation models has increased during the last ten years. Such models are found to be valuable tools considering process optimization and the development of new processes. The application of simulation models makes it possible to reduce the number of time-consuming experiments. The present work concentrates on the Cylindrical Mandrel drawing of tubes. If the total reduction is small, i.e., if not more than one drawing pass is necessary, this process is characterized by high productivity: compared to pilger rolling the process has been estimated to be about eight times faster. Tubes which have been manufactured by means of Cylindrical Mandrel drawing are distinguished by close tolerance and good surface smoothness. The tubes are often delivered in the cold-drawn, strain-hardened condition, i.e., without a subsequent annealing. Because the customer often orders a product of minimum yield stress, it is of great importance to be able to predict the strains of the tube material. The theoretical part of this study comprises the development of a simulation model based on the matrix method, the model being utilized for prediction of strains. In the experimental part a high precision investigation considering one workpiece is presented. This sample was furnished with a square network in the axial plane of symmetry. Strain distributions from theory and experiment are found to be in good agreement.
H. Kudo - One of the best experts on this subject based on the ideXlab platform.
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A flexible shear spinning of axi-symmetrical shells with a general-purpose Mandrel
Journal of Materials Processing Technology, 2007Co-Authors: K. Kawai, L.-n. Yang, H. KudoAbstract:Abstract An experimental study is conducted to survey the technological possibility of the shear spinning of truncated hemispherical shells with a Cylindrical Mandrel for general purposes using A1050-H and A1050-O commercially pure aluminum sheets of 1 mm thickness. It is found that there exist forming limits to prevent the occurrence of wall fractures and flange wrinkles during the spinning process of truncated hemispherical shells. It is also found that the sine law is not realized exactly in shear spinning of truncated hemispherical shells with a Cylindrical Mandrel for general purposes due to the spring back of the workpiece.
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A flexible shear spinning of truncated conical shells with a general-purpose Mandrel
Journal of Materials Processing Technology, 2001Co-Authors: K. Kawai, L.-n. Yang, H. KudoAbstract:Abstract An experimental study was conducted to survey the technological possibility of the die-less shear spinning of truncated conical shells with a Cylindrical Mandrel for general purposes using A1050-H and A1050-O commercially pure aluminum sheets of 1 mm thickness. It was clarified that there exist forming limits to prevent the occurrence of wall fractures and flange wrinkles during the die-less shear spinning process. The sine law was also realized in the die-less shear spinning. Truncated conical shells can be manufactured practically with a certain degree of accuracy by the die-less shear spinning with a Cylindrical Mandrel for general purposes.
Stanislaw Urbanski - One of the best experts on this subject based on the ideXlab platform.
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Cylindrical Mandrel drawing of tubes a matrix method simulation compared with experiment
Journal of Materials Processing Technology, 1992Co-Authors: Stanislaw Urbanski, Marek Packo, Ulf Stahlberg, Hans KeifeAbstract:Abstract The demand from industry for metal-forming simulation models has increased during the last ten years. Such models are found to be valuable tools considering process optimization and the development of new processes. The application of simulation models makes it possible to reduce the number of time-consuming experiments. The present work concentrates on the Cylindrical Mandrel drawing of tubes. If the total reduction is small, i.e., if not more than one drawing pass is necessary, this process is characterized by high productivity: compared to pilger rolling the process has been estimated to be about eight times faster. Tubes which have been manufactured by means of Cylindrical Mandrel drawing are distinguished by close tolerance and good surface smoothness. The tubes are often delivered in the cold-drawn, strain-hardened condition, i.e., without a subsequent annealing. Because the customer often orders a product of minimum yield stress, it is of great importance to be able to predict the strains of the tube material. The theoretical part of this study comprises the development of a simulation model based on the matrix method, the model being utilized for prediction of strains. In the experimental part a high precision investigation considering one workpiece is presented. This sample was furnished with a square network in the axial plane of symmetry. Strain distributions from theory and experiment are found to be in good agreement.
K. Kawai - One of the best experts on this subject based on the ideXlab platform.
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A flexible shear spinning of axi-symmetrical shells with a general-purpose Mandrel
Journal of Materials Processing Technology, 2007Co-Authors: K. Kawai, L.-n. Yang, H. KudoAbstract:Abstract An experimental study is conducted to survey the technological possibility of the shear spinning of truncated hemispherical shells with a Cylindrical Mandrel for general purposes using A1050-H and A1050-O commercially pure aluminum sheets of 1 mm thickness. It is found that there exist forming limits to prevent the occurrence of wall fractures and flange wrinkles during the spinning process of truncated hemispherical shells. It is also found that the sine law is not realized exactly in shear spinning of truncated hemispherical shells with a Cylindrical Mandrel for general purposes due to the spring back of the workpiece.
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A flexible shear spinning of truncated conical shells with a general-purpose Mandrel
Journal of Materials Processing Technology, 2001Co-Authors: K. Kawai, L.-n. Yang, H. KudoAbstract:Abstract An experimental study was conducted to survey the technological possibility of the die-less shear spinning of truncated conical shells with a Cylindrical Mandrel for general purposes using A1050-H and A1050-O commercially pure aluminum sheets of 1 mm thickness. It was clarified that there exist forming limits to prevent the occurrence of wall fractures and flange wrinkles during the die-less shear spinning process. The sine law was also realized in the die-less shear spinning. Truncated conical shells can be manufactured practically with a certain degree of accuracy by the die-less shear spinning with a Cylindrical Mandrel for general purposes.
David Linton Johnson - One of the best experts on this subject based on the ideXlab platform.
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Tube waves and Mandrel modes: Experiment and theory
Journal of the Acoustical Society of America, 1997Co-Authors: Sergio Kostek, David Linton JohnsonAbstract:The characteristics of tube waves in a borehole, with and without a solid Cylindrical Mandrel, which may be either elastic or poro-elastic, are compared. With an elastic Mandrel, the tube waves are slower, more dispersive, and more sensitive to the formation shear modulus than without. Similarly extensional mode characteristics are compared in the presence of a formation. In the presence of an elastic formation the extensional mode is faster, more dispersive than without, and it is only slightly sensitive to the formation shear properties. These calculated characteristics are in excellent agreement with our measured data. Additionally, the characteristics of tube waves and extensional modes are studied in a borehole in the presence of a concentric liquid-saturated porous Mandrel whose acoustic properties are calculated using the Biot theory. The coupling of the tube wave propagating in the annulus with the slow wave propagating in the porous Mandrel introduces attenuation and additional dispersion to the ...
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Mandrel effects on tube waves
Journal of the Acoustical Society of America, 1996Co-Authors: Robert Bailey, Sergio Kostek, David Linton JohnsonAbstract:The characteristics of tube waves in water‐filled boreholes with and without an elastic Cylindrical Mandrel in the borehole are compared. With a Mandrel, the tube waves are slower, more dispersive, and more sensitive to the formation shear modulus than without. Additionally, the characteristics of tube waves in a borehole in the presence of a liquid‐saturated porous Mandrel were also studied. The tube waves propagating in the annulus couple with the slow waves propagating in the porous Mandrel. This coupling and the viscous dissipation of the slow waves introduce attenuation and additional dispersion to the tube waves. Whether the Mandrel is porous or not, there are two modes which are weakly dispersive in the quasistatic limit. Very roughly, the two modes consist of an extensional mode in the rod and a fluid‐based mode in the annulus which are coupled together.
