Metal Forming With Vibrated Tools

1969 ◽  
Vol 91 (4) ◽  
pp. 1168-1174 ◽  
Author(s):  
Ivan Kristoffy
Keyword(s):  
Metal Forming ◽  
Necessary Conditions ◽  
Force Measurement ◽  
Cold Forging ◽  
Dynamic Force ◽  
Forming Force ◽  
Continuous Forming ◽  
Tool Vibration ◽  
State Of Stress ◽  
Force Reduction

The results of superimposed 20- and 20,000-cps tool vibration in deep drawing, ironing, and cold-forging are presented. Equipment and instrumentation are discussed. The importance of proper dynamic force measurement is emphasized. It was found that: (a) punch vibration resulted in only an apparent force reduction proportional to the workpiece stiffness and vibration amplitude; (b) die vibration caused a true forming force reduction either by changing the direction of friction force or by altering the state of stress; (c) material properties were not affected, although in cold-forging, with superimposed 20,000 cps punch vibration, an apparent force drop of up to 60 percent was achieved; (d) surface finish and deep drawability of the material, under certain conditions, were slightly improved. It is recommended to use superimposed tool vibration only in continuous forming operations, and then only if certain necessary conditions can be satisfied.

Rigid-Plastic Finite Element Simulation of Cold Forging and Sheet Metal Forming by Eulerian Meshing Method

2014 ◽  
Vol 970 ◽  
pp. 177-184 ◽  
Author(s):  
Wen Chiet Cheong ◽  
Heng Keong Kam ◽  
Chan Chin Wang ◽  
Ying Pio Lim
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Large Deformation ◽  
Sheet Metal ◽  
Metal Forming ◽  
The Body ◽  
Cold Forging ◽  
Rigid Plastic ◽  
Element Analysis ◽  
Linear Solution

A computational technique of rigid-plastic finite element method by using the Eulerian meshing method was developed to deal with large deformation problem in metal forming by replacing the conventional way of applying complicated remeshing schemes when using the Lagrange’s elements. During metal forming process, a workpiece normally undergoes large deformation and causes severe distortion of elements in finite element analysis. The distorted element may lead to instability in numerical calculation and divergence of non-linear solution in finite element analysis. With Eulerian elements, the initial elements are generated to fix into a specified analytical region with particles implanted as markers to form the body of a workpiece. The particles are allowed to flow between the elements after each deformation step to show the deforming pattern of material. Four types of cold forging and sheet metal clinching were conducted to investigate the effectiveness of the presented method. The proposed method is found to be effective by comparing the results on dimension of the final product, material flow behaviour and punch load versus stroke obtained from simulation and experiment.

Material Characterization for Sheet-Bulk Metal Forming

2012 ◽  
Vol 504-506 ◽  
pp. 1029-1034 ◽  
Author(s):  
Bernd Arno Behrens ◽  
Kathrin Voges-Schwieger ◽  
Anas Bouguecha ◽  
Jens Mielke ◽  
Milan Vucetic
Keyword(s):  
Metal Forming ◽  
Material Characterization ◽  
Cyclic Load ◽  
Material Behavior ◽  
Forming Force ◽  
Forming Process ◽  
Bulk Metal ◽  
Bulk Metal Forming ◽  
Metal Forming Process

Sheet-bulk metal forming is a novel manufacturing technology, which unites the advantages and design solutions of sheet metal and bulk metal forming. To challenge the high forming force the process is superimposed with an oscillation in the main flow of the process. The paper focuses on the characterization of the material behavior under cyclic load and the effects for the sheet bulk metal forming process.

Fließpressen hohler Wellen mit Wanddickenvariation/Cold forging of hollow shafts with wall thickness variation – Numerical investigation of a hollow forward extrusion process with adjustable deformation zone

2020 ◽  
Vol 110 (10) ◽  
pp. 684-688
Author(s):  
Alexander Weiß ◽  
Mathias Liewald
Keyword(s):  
Numerical Investigation ◽  
Metal Forming ◽  
Extrusion Process ◽  
Cold Forging ◽  
Thickness Variation ◽  
Part Geometry ◽  
Forming Technology ◽  
Wall Thickness Variation ◽  
The University ◽  
Hollow Shafts

Die Fertigung von Hohlwellen mit komplexer Innengeometrie bedingte bisher meist aufwendige Prozessrouten. Ein am Institut für Umformtechnik der Universität Stuttgart entwickeltes Kaltfließpressverfahren soll nun die wirtschaftliche und flexible Fertigung von Hohlwellen mit Wanddickenvariation ermöglichen. In diesem Beitrag werden das Verfahren beschrieben und die Ergebnisse der numerischen Untersuchung des Einflusses der Werkzeugkinematik auf die erzielbare Pressteilgeometrie dargelegt.   Usually, the production of hollow shafts with complex internal geometry by cold forging requires extensive process routes. A novel cold forging process developed at the Institute for Metal Forming Technology at the University of Stuttgart allows for an economical and flexible production of hollow shafts. This article describes the manufacturing process and presents the results of a numerical investigation for determining the influence of tool kinematics on the achievable part geometry.

Ultrasonic-Assisted Metal Staking with 15 kHz Oscillation Frequency

2016 ◽  
Vol 716 ◽  
pp. 536-543
Author(s):  
Uwe Leicht ◽  
Marion Merklein ◽  
Sebastian Engler
Keyword(s):  
Force Measurement ◽  
High Strength ◽  
Industrial Applications ◽  
High Frequency Oscillation ◽  
Laser Vibrometer ◽  
Frequency Oscillation ◽  
Mean Values ◽  
High Dependency ◽  
Ultrasonic Assisted ◽  
Force Reduction

To comply with increasing product requirements, the use of function-optimized materialsis claimed. Joining technology thereby becomes increasingly important to use high strength materialonly in postulated sections. Staking is a joining by forming technology that is highly reliable andcost efficient. High process forces and sufficient formability of the material limit the suitability inclaimed miniaturization for use in industrial applications. A promising approach to break these processlimitations is the use of superposed high frequency oscillation, whereby joining forces could bedecreased. The present study indicates first trials of an ultrasonic (US) assisted staking process of highstrength martensitic steel. Based on high temporal instrumentation, such as laser vibrometer, contactdetection and high-resolution force measurement, the process sequence is characterized and studiedin detail. The researches confirm high potential in force reduction of mean values due to superimposedhigh frequency oscillation with a high dependency on amplitudes. In process, two differentforce-characteristics within three regimes can be identified. Since US assisted forming processes arewell known in literature with harmonic oscillating force signals during process, hammering and soirregular force peaks with changes in contact signal within process, are identified for first time anddemonstrate a highly promising field of application.

Dynamic Force Measurement of Model Container to Centrifuge Nacelle Used in Centrifuge Model Explosion Test

2010 ◽  
Vol 439-440 ◽  
pp. 1393-1397
Author(s):  
Xiao Hong Yue ◽  
Yong Jian Mao ◽  
Hao Pu ◽  
Bao Liang Niu ◽  
Lei Wang ◽  
...  
Keyword(s):  
Force Measurement ◽  
Low Cost ◽  
Dynamic Environment ◽  
Dynamic Strain ◽  
Centrifuge Model Test ◽  
Dynamic Force ◽  
Geotechnical Centrifuge ◽  
Centrifuge Model ◽  
Explosion Test ◽  
Compressive Tests

The technique of centrifuge model test has been widely used in geotechnical mechanics and engineering because of its low cost and low test scale. In order to investigate the dynamic behaviors of the geotechnical model under explosion, we are developing an explosion geotechnical centrifuge. The dynamic environment of explosion is necessary to be determined for the strength design of the centrifuge nacelle. This paper presents the dynamic force measurement of the model container to the centrifuge nacelle under a typical explosion. Firstly, three cylindrical supports were designed and calibrated by quasi-static compressive tests. The force-strain relations are measured and linearly fitted. Secondly, an explosion test was performed and the dynamic strain histories of the supports were measured. Then the dynamic force histories were obtained combined with the calibration results. The investigation provides an understanding of the dynamic environment for the centrifuge nacelle design.

Dynamic Force Measurement with Strain Gauges

1974 ◽  
Vol 42 (2) ◽  
pp. 108-110
Author(s):  
Bruce E. Lee
Keyword(s):  
Force Measurement ◽  
Strain Gauges ◽  
Dynamic Force

New Giant Magnetostrictive Force Sensors

2013 ◽  
Vol 816-817 ◽  
pp. 424-428
Author(s):  
Rong Ge Yan ◽  
Li Hua Zhu ◽  
Qing Xin Yang
Keyword(s):  
Force Measurement ◽  
Force Sensor ◽  
Measurement Range ◽  
Magnetic Flux Density ◽  
Force Sensors ◽  
Dynamic Force ◽  
Element Analysis ◽  
Giant Magnetostrictive Materials ◽  
Overload Capacity ◽  
Adjustable Range

Force sensors, based on the giant inverse magnetostrictive effect, have a series of outstanding properties, such as large overload capacity, which make them have more and more applications to the field of automatic control system of heavy industry, chemical industry. This paper designs new giant magnetostrictive force sensors using the rare-earth iron giant magnetostrictive materials. With the designed giant magnetostrictive force sensor, the relations between magnetic flux density in the gap and applied static stress on the sensor, the inductive voltage in the coil and time (with the dynamic stress), are calculated by finite element analysis software. The related confirmatory experiments have been conducted. The experimental results indicate that the giant magnetostrictive force sensor is fit for static and dynamic force measurement. In order to enlarge the measurement range, the designed force sensor as the basic cell is combined. This paper gives two kinds of combinations, which have the feature of adjustable range.

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