ABSTRACT The industrial aim for shorter lead times in the development process for new products ha... more ABSTRACT The industrial aim for shorter lead times in the development process for new products has encouraged a fast development of finite-element procedures for the simulation of sheet-metal forming. These procedures can shorten the design stage for new sheet-forming tools and the try-out period. In order to reach these goals robust calculation procedures and extensive verification of results are required. This paper presents a detailed validation of one promising type of finite-element code, namely the explicit code DYNA3D. Experiments for verification were performed on a zinc-coated sheet steel with a hot-dip galvanized coating. Stretch forming and deep drawing of cylindrical cups were performed. Rectangular boxes were formed from rectangular blanks and blanks with cut corners. Dies both with and without draw beads were used. Punch forces, flange draw-in and strain distributions were measured.The pressings with cylindrical shape were used to determine coefficients of friction with a fitting procedure based on comparison of data from pressings and from the DYNA3D calculations. These tribological data and constitutive data of the steels were used in the simulation of pressings of rectangular boxes. The calculations with DYNA3D gave a good description of flange draw-in and the strain distributions in the pressings. In most of the cases studied the punch-force curves were well reproduced. It is concluded that the present code is well suited for the simulation of sheet-forming operations.
Journal of Materials Processing Technology, Nov 1, 1993
ABSTRACT The industrial aim for shorter lead times in the development process for new products ha... more ABSTRACT The industrial aim for shorter lead times in the development process for new products has encouraged a fast development of finite-element procedures for the simulation of sheet-metal forming. These procedures can shorten the design stage for new sheet-forming tools and the try-out period. In order to reach these goals robust calculation procedures and extensive verification of results are required. This paper presents a detailed validation of one promising type of finite-element code, namely the explicit code DYNA3D. Experiments for verification were performed on a zinc-coated sheet steel with a hot-dip galvanized coating. Stretch forming and deep drawing of cylindrical cups were performed. Rectangular boxes were formed from rectangular blanks and blanks with cut corners. Dies both with and without draw beads were used. Punch forces, flange draw-in and strain distributions were measured.The pressings with cylindrical shape were used to determine coefficients of friction with a fitting procedure based on comparison of data from pressings and from the DYNA3D calculations. These tribological data and constitutive data of the steels were used in the simulation of pressings of rectangular boxes. The calculations with DYNA3D gave a good description of flange draw-in and the strain distributions in the pressings. In most of the cases studied the punch-force curves were well reproduced. It is concluded that the present code is well suited for the simulation of sheet-forming operations.
ABSTRACT The industrial aim for shorter lead times in the development process for new products ha... more ABSTRACT The industrial aim for shorter lead times in the development process for new products has encouraged a fast development of finite-element procedures for the simulation of sheet-metal forming. These procedures can shorten the design stage for new sheet-forming tools and the try-out period. In order to reach these goals robust calculation procedures and extensive verification of results are required. This paper presents a detailed validation of one promising type of finite-element code, namely the explicit code DYNA3D. Experiments for verification were performed on a zinc-coated sheet steel with a hot-dip galvanized coating. Stretch forming and deep drawing of cylindrical cups were performed. Rectangular boxes were formed from rectangular blanks and blanks with cut corners. Dies both with and without draw beads were used. Punch forces, flange draw-in and strain distributions were measured.The pressings with cylindrical shape were used to determine coefficients of friction with a fitting procedure based on comparison of data from pressings and from the DYNA3D calculations. These tribological data and constitutive data of the steels were used in the simulation of pressings of rectangular boxes. The calculations with DYNA3D gave a good description of flange draw-in and the strain distributions in the pressings. In most of the cases studied the punch-force curves were well reproduced. It is concluded that the present code is well suited for the simulation of sheet-forming operations.
... FRETTING BENCH-TEST Tag Hammam KIMAB Stockholm, Sweden tag.hammam@kimab. com ... Mode III Cir... more ... FRETTING BENCH-TEST Tag Hammam KIMAB Stockholm, Sweden tag.hammam@kimab. com ... Mode III Circumferential relative displacement Figure 1. Schematic figure of the three basic fretting modes in the case of ball-on-flat contact geometry [6]. ...
Proceedings of the Fifty-First IEEE Holm Conference on Electrical Contacts, 2005., 2005
... FRETTING BENCH-TEST Tag Hammam KIMAB Stockholm, Sweden tag.hammam@kimab. com ... Mode III Cir... more ... FRETTING BENCH-TEST Tag Hammam KIMAB Stockholm, Sweden tag.hammam@kimab. com ... Mode III Circumferential relative displacement Figure 1. Schematic figure of the three basic fretting modes in the case of ball-on-flat contact geometry [6]. ...
IEEE Transactions on Components and Packaging Technologies, 2000
... 2. The contact used in the test con-sisted of one flat, stationary sample and one hemispheric... more ... 2. The contact used in the test con-sisted of one flat, stationary sample and one hemispheric rider with a tip radius of 2 mm. ... Page 2. HAMMAM: IMPACT OF SLIDING MOTION AND CURRENT LOAD ON THE DETERIORATION OF TIN-COATED CONTACT TERMINALS 279 Fig. ...
Electrical Contacts, 1996., Proceedings of the …, 1996
... Tag Hammam Swedish Institute for Metals Research Drottning Kristinas v 48 S-II 4 28 Stockhol... more ... Tag Hammam Swedish Institute for Metals Research Drottning Kristinas v 48 S-II 4 28 Stockholm, Sweden ... 1 The tested model contact consists of two parts: one flat stationary sample, and one moving hemisphere with a tip radius of 2mm called rider in the following text. ...
ABSTRACT For bulk solid-solid interfaces, the thermal contact resistance TCR) is generally attrib... more ABSTRACT For bulk solid-solid interfaces, the thermal contact resistance TCR) is generally attributed to a mismatch in the acoustic impedances (density x sound velocity) of each medium [1]. Here, we present a novel study of the TCR for a bulk Silicon crystal (111) in contact with superfluid helium, as a function of the acoustic impedance of the superfluid. The cell design and experimental technique are discussed in [2]. The acoustic impedance is varied by monitoring the pressure of the superfluid. Measurements are carried-out at T~1.8 K, from a few torrs (vapor pressure) up to 25 bars, corresponding to approximately an 80% change in the acoustic impedance of the superfluid. The experiments show no change in TCR over the entire pressure range, indicating a negligible contribution due to the acoustic impedances. A comparison to the diffuse mismatch model [1] is discussed.
ABSTRACT The industrial aim for shorter lead times in the development process for new products ha... more ABSTRACT The industrial aim for shorter lead times in the development process for new products has encouraged a fast development of finite-element procedures for the simulation of sheet-metal forming. These procedures can shorten the design stage for new sheet-forming tools and the try-out period. In order to reach these goals robust calculation procedures and extensive verification of results are required. This paper presents a detailed validation of one promising type of finite-element code, namely the explicit code DYNA3D. Experiments for verification were performed on a zinc-coated sheet steel with a hot-dip galvanized coating. Stretch forming and deep drawing of cylindrical cups were performed. Rectangular boxes were formed from rectangular blanks and blanks with cut corners. Dies both with and without draw beads were used. Punch forces, flange draw-in and strain distributions were measured.The pressings with cylindrical shape were used to determine coefficients of friction with a fitting procedure based on comparison of data from pressings and from the DYNA3D calculations. These tribological data and constitutive data of the steels were used in the simulation of pressings of rectangular boxes. The calculations with DYNA3D gave a good description of flange draw-in and the strain distributions in the pressings. In most of the cases studied the punch-force curves were well reproduced. It is concluded that the present code is well suited for the simulation of sheet-forming operations.
Journal of Materials Processing Technology, Nov 1, 1993
ABSTRACT The industrial aim for shorter lead times in the development process for new products ha... more ABSTRACT The industrial aim for shorter lead times in the development process for new products has encouraged a fast development of finite-element procedures for the simulation of sheet-metal forming. These procedures can shorten the design stage for new sheet-forming tools and the try-out period. In order to reach these goals robust calculation procedures and extensive verification of results are required. This paper presents a detailed validation of one promising type of finite-element code, namely the explicit code DYNA3D. Experiments for verification were performed on a zinc-coated sheet steel with a hot-dip galvanized coating. Stretch forming and deep drawing of cylindrical cups were performed. Rectangular boxes were formed from rectangular blanks and blanks with cut corners. Dies both with and without draw beads were used. Punch forces, flange draw-in and strain distributions were measured.The pressings with cylindrical shape were used to determine coefficients of friction with a fitting procedure based on comparison of data from pressings and from the DYNA3D calculations. These tribological data and constitutive data of the steels were used in the simulation of pressings of rectangular boxes. The calculations with DYNA3D gave a good description of flange draw-in and the strain distributions in the pressings. In most of the cases studied the punch-force curves were well reproduced. It is concluded that the present code is well suited for the simulation of sheet-forming operations.
ABSTRACT The industrial aim for shorter lead times in the development process for new products ha... more ABSTRACT The industrial aim for shorter lead times in the development process for new products has encouraged a fast development of finite-element procedures for the simulation of sheet-metal forming. These procedures can shorten the design stage for new sheet-forming tools and the try-out period. In order to reach these goals robust calculation procedures and extensive verification of results are required. This paper presents a detailed validation of one promising type of finite-element code, namely the explicit code DYNA3D. Experiments for verification were performed on a zinc-coated sheet steel with a hot-dip galvanized coating. Stretch forming and deep drawing of cylindrical cups were performed. Rectangular boxes were formed from rectangular blanks and blanks with cut corners. Dies both with and without draw beads were used. Punch forces, flange draw-in and strain distributions were measured.The pressings with cylindrical shape were used to determine coefficients of friction with a fitting procedure based on comparison of data from pressings and from the DYNA3D calculations. These tribological data and constitutive data of the steels were used in the simulation of pressings of rectangular boxes. The calculations with DYNA3D gave a good description of flange draw-in and the strain distributions in the pressings. In most of the cases studied the punch-force curves were well reproduced. It is concluded that the present code is well suited for the simulation of sheet-forming operations.
... FRETTING BENCH-TEST Tag Hammam KIMAB Stockholm, Sweden tag.hammam@kimab. com ... Mode III Cir... more ... FRETTING BENCH-TEST Tag Hammam KIMAB Stockholm, Sweden tag.hammam@kimab. com ... Mode III Circumferential relative displacement Figure 1. Schematic figure of the three basic fretting modes in the case of ball-on-flat contact geometry [6]. ...
Proceedings of the Fifty-First IEEE Holm Conference on Electrical Contacts, 2005., 2005
... FRETTING BENCH-TEST Tag Hammam KIMAB Stockholm, Sweden tag.hammam@kimab. com ... Mode III Cir... more ... FRETTING BENCH-TEST Tag Hammam KIMAB Stockholm, Sweden tag.hammam@kimab. com ... Mode III Circumferential relative displacement Figure 1. Schematic figure of the three basic fretting modes in the case of ball-on-flat contact geometry [6]. ...
IEEE Transactions on Components and Packaging Technologies, 2000
... 2. The contact used in the test con-sisted of one flat, stationary sample and one hemispheric... more ... 2. The contact used in the test con-sisted of one flat, stationary sample and one hemispheric rider with a tip radius of 2 mm. ... Page 2. HAMMAM: IMPACT OF SLIDING MOTION AND CURRENT LOAD ON THE DETERIORATION OF TIN-COATED CONTACT TERMINALS 279 Fig. ...
Electrical Contacts, 1996., Proceedings of the …, 1996
... Tag Hammam Swedish Institute for Metals Research Drottning Kristinas v 48 S-II 4 28 Stockhol... more ... Tag Hammam Swedish Institute for Metals Research Drottning Kristinas v 48 S-II 4 28 Stockholm, Sweden ... 1 The tested model contact consists of two parts: one flat stationary sample, and one moving hemisphere with a tip radius of 2mm called rider in the following text. ...
ABSTRACT For bulk solid-solid interfaces, the thermal contact resistance TCR) is generally attrib... more ABSTRACT For bulk solid-solid interfaces, the thermal contact resistance TCR) is generally attributed to a mismatch in the acoustic impedances (density x sound velocity) of each medium [1]. Here, we present a novel study of the TCR for a bulk Silicon crystal (111) in contact with superfluid helium, as a function of the acoustic impedance of the superfluid. The cell design and experimental technique are discussed in [2]. The acoustic impedance is varied by monitoring the pressure of the superfluid. Measurements are carried-out at T~1.8 K, from a few torrs (vapor pressure) up to 25 bars, corresponding to approximately an 80% change in the acoustic impedance of the superfluid. The experiments show no change in TCR over the entire pressure range, indicating a negligible contribution due to the acoustic impedances. A comparison to the diffuse mismatch model [1] is discussed.
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