Experimental Investigations of Different Tool Concepts for Rotary Peen Forming

2013 ◽  
Vol 549 ◽  
pp. 53-60 ◽  
Author(s):  
Christoph Russig ◽  
Markus Bambach ◽  
Gerhard Hirt
Keyword(s):  
Surface Quality ◽  
Machine Design ◽  
Experimental Investigations ◽  
Plastic Layer ◽  
Circular Trajectory ◽  
Forming Process ◽  
The Third ◽  
Peen Forming ◽  
Structural Parts ◽  
Localized Plastic Deformation

Rotary Peen Forming (RPF) is a new peen forming process, comparable to Shot Peen Forming (SPF), in which the shot is held by a flexible connection and moved on a circular trajectory. Hence, RPF uses less machine components and therefore offers a compact machine design and a more flexible use than SPF. Just as conventional Shot Peen Forming the RPF process causes localized plastic deformation but involves tangential components which can create shear deformation in the plastic layer. In this paper, three different RPF tool concepts are compared and the applicability of Rotary Peen Forming for the production of slightly curved parts is analyzed. The first design offers a stochastic impact distribution, the second design leads to deterministic impacts. The third one is a further enhancement of the previous designs and combines the advantages of both. In contrast to previous tests a new, stiffer testing setup was used which offers good comparability of the tool concepts. Particularly the forming potential in terms of the realization of high curvatures and the surface quality are investigated. Depending on the tool concept the surface quality differs significantly, but generally RPF allows the forming of curvatures that are commonly used for aerospace structural parts.

A New Tool Concept for Rotary Peen Forming with Defined Impact Positions

2012 ◽  
Vol 504-506 ◽  
pp. 925-930 ◽  
Author(s):  
Christoph Russig ◽  
Markus Bambach ◽  
Gerhard Hirt
Keyword(s):  
Plastic Deformation ◽  
Machine Design ◽  
Plastic Layer ◽  
Circular Trajectory ◽  
Forming Process ◽  
Numerical Investigations ◽  
Process Characteristics ◽  
Peen Forming ◽  
Set Up ◽  
Localized Plastic Deformation

Rotary peen forming (RPF) has been developed as a new peen forming process in which the shot is held by a flexible connection and moved on a circular trajectory (see Fig. 1 below). The main advantage compared to a traditional shot peen forming (SPF) processes is that RPF does not need refeed of shot particles. Hence, RPF offers a compact machine design and a flexible use. The RPF process causes localized plastic deformation just as in traditional shot peen forming but involves tangential components which can create shear deformation in the plastic layer. These tangential components depend on the connection used for the setup. Compared to traditional shot peen forming, RPF shows different process characteristics in terms of coverage and the shape of indentations created on the surface of the workpiece. In this paper, a new tool concept for rotary peen forming is evaluated using experiments and numerical investigations of the process. The set-up uses a spring-attenuator system, which leads to more deterministic impact positions than previously used wire-based impactor concepts.

Schwingungsüberlagertes Axialformen/Superimposed Oscillated Axial Forming

2020 ◽  
Vol 110 (11-12) ◽  
pp. 838-843
Author(s):  
Philipp Müller ◽  
Bernd-Arno Behrens ◽  
Sven Hübner ◽  
Hendrik Vogt ◽  
Daniel Rosenbusch ◽  
...  
Keyword(s):  
Surface Quality ◽  
Economic Importance ◽  
Combined Effect ◽  
Wird Eine ◽  
Forming Force ◽  
Forming Process ◽  
Forming Technology ◽  
Great Economic Importance ◽  
Gear Geometry

Techniken zur Steigerung der Formgebungsgrenzen in der Umformtechnik sind von hoher wirtschaftlicher Bedeutung. In dieser Arbeit wird eine Schwingungsüberlagerung im Krafthauptfluss eines Axialformprozesses zur Ausprägung einer Verzahnungsgeometrie untersucht. Die Auswirkungen der Schwingung auf die erzielbare Ausfüllung der Zahnkavitäten werden analysiert sowie die Parameter Schmierung und Oberflächengüte der Halbzeuge in ihrer kombinierten Wirkung untersucht. Es konnte eine Reduzierung der mittleren Umformkraft sowie eine Erhöhung der Formfüllung festgestellt werden. Techniques for extending the production limits in forming technology are of great economic importance. In this research, a superimposed oscillation in the main force flow of an axial forming process to form an axial gear geometry is investigated. The effects of the superimposed oscillation on the achievable form-filling of the tooth cavities are analyzed and the parameters lubrication and surface quality of the semi-finished products are investigated in their combined effect. A reduction of the averaged forming force as well as an increase of the form-filling could be achieved.

Dispersion Flow in Microchannels

2012 ◽  
Author(s):  
Alfir T. Akhmetov ◽  
Marat V. Mavletov ◽  
Sergey P. Sametov ◽  
Artur A. Rakhimov ◽  
Azat A. Valiev ◽  
...  
Keyword(s):  
Aqueous Phase ◽  
Effective Viscosity ◽  
Complex Structure ◽  
Experimental Investigations ◽  
Dispersed Phase ◽  
Rheological Characteristics ◽  
Dense Structure ◽  
The Third ◽  
Dynamic Blocking ◽  
Oil Emulsions

The work is devoted to experimental investigations of the features of flow of dispersions in microchannels. The paper consists of three parts. In the first part the flow of emulsions in smooth contracting cylindrical microchannels is investigated. It is received that a significant role at dynamic blocking of channels is played by the inclusions comparable by size to the diameter of a narrowing. This is in spite of the fact that their influence on the change of a flow rate of emulsion before blocking is insignificant. In the second part the generation of emulsion in a complex structure of microchannels (micromodels) when water is displaced by composition of hydrocarbon with surfactants is investigated. The experimental dependences of the rheological characteristics of emulsions based on the composition of SAS and water at different concentrations of the aqueous phase can explain blocking of a porous structure by generated emulsion. In the third part a comparison of flow of water-in-oil emulsions with the suspension which was obtained by freezing the microdroplets of the aqueous phase of emulsions was studied. It was found that the blocking of suspension is not as complete as in the case of emulsion. It is explained by deformation of the droplets and by formation of a dense structure, as opposed to suspension of beads, through which hydrocarbon phase is filtered. A small increase in effective viscosity due to solidification of freezing droplets of the dispersed phase was found.

Modelling and Analysis of Integrated Hotforming and Quenching Processes

2005 ◽  
Vol 6-8 ◽  
pp. 787-794 ◽  
Author(s):  
D. Lorenz ◽  
Karl Roll
Keyword(s):  
Lightweight Design ◽  
Experimental Investigations ◽  
Boron Steel ◽  
General Tendency ◽  
The Finite Element Method ◽  
Contact Heat ◽  
Simulation Accuracy ◽  
Structural Part ◽  
Component Strength ◽  
Structural Parts

In the automotive industry a general tendency to choose steels with enhanced strength for structural parts can be observed. This trend results from the increased lightweight design efforts to satisfy the fleet consumption restrictions. Hot forming and quenching of boron steel offers the possibility to improve the component strength and reduce the weight of structural parts. The main influences on the process are described and a method to model and simulate this process using the finite element method using LS-DYNA is presented. Experimental investigations of the contact heat transfer have been carried out to enhance the simulation accuracy. A prototyping tool of a structural part is used to examine the process under production conditions. Temperatures of the tool and the part are measured during the process. These temperatures are compared with the simulation results in order to reevaluate the results of the process simulation.

Numerical and Experimental Investigations of Multistage Sheet-Bulk Metal Forming Process with Compound Press Tools

2015 ◽  
Vol 651-653 ◽  
pp. 1153-1158 ◽  
Author(s):  
Bernd Arno Behrens ◽  
Anas Bouguecha ◽  
Milan Vucetic ◽  
Sven Hübner ◽  
Daniel Rosenbusch ◽  
...  
Keyword(s):  
Metal Forming ◽  
Solid Metal ◽  
Experimental Investigations ◽  
Metal Component ◽  
Forming Process ◽  
Bulk Metal ◽  
Bulk Metal Forming ◽  
Process Sequence ◽  
Metal Forming Process ◽  
Flange Forming

Sheet-bulk metal forming is a manufacturing technology, which allows to produce a solid metal component out of a flat sheet. This paper focuses on numerical and experimental investigations of a new multistage forming process with compound press tools. The complete process sequence for the production of this solid metal component consists of three forming stages, which include a total of six production techniques. The first forming stage includes deep drawing, simultaneous cutting and following wall upsetting. In the second forming stage, flange forming combined with cup bottom ironing takes place. In the last stage of the process sequence, the component is sized. To investigate and to improve process parameters such as plastic strain distribution, resulting dimensions and process forces, FEA is performed. Based on these results the developed process is designed.

Influence of Manufacturing Process on the Fatigue Strength of Gears

2014 ◽  
Vol 1018 ◽  
pp. 269-276
Author(s):  
Andrea Reiß ◽  
Ulf Engel
Keyword(s):  
Fatigue Strength ◽  
Surface Quality ◽  
Fatigue Behavior ◽  
High Surface ◽  
Research Work ◽  
Dimensional Accuracy ◽  
Cold Forging ◽  
Hardness Distribution ◽  
Forming Process ◽  
High Surface Quality

With cold forging processes it is possible to produce parts characterized by high strength, high dimensional accuracy and high surface quality. In order to optimize the forming process and to be able to use the advantages of cold forging specifically and combined, it is necessary to find correlations between manufacturing parameters on the one side, strength and other properties like hardness distribution and surface quality of the component on the other side. The research work covered in this paper focuses on the correlation of the components properties influenced by its manufacturing history and their fatigue strength. The used component is a gear produced by a lateral cold forging process. For the investigations an experimental setup has been designed. The aim for the design of the setup is to reproduce the real contact condition for the contact of two gears. To obtain different component properties the production process of the gear was varied by producing the parts by a milling operation. First of all, the components’ properties, for example hardness distribution, remaining residual stresses, orientation of fibers and surface quality, were determined. The components’ fatigue behavior was determined using a high frequency pulsator and evaluated in terms of finite life fatigue strength and fatigue endurance limit. These examinations were used to produce Woehler curves for the differently manufactured components with a certain statistical data analysis method.

Shaping of Ceramics Using Residual Stresses

2013 ◽  
Vol 768-769 ◽  
pp. 478-483
Author(s):  
Heiko Höpfel ◽  
Wulf Pfeiffer
Keyword(s):  
Shot Peening ◽  
Surface Region ◽  
Cyclic Strength ◽  
Common Procedure ◽  
Near Surface ◽  
Peen Forming ◽  
Deformation Work ◽  
Stress States ◽  
Underlying Mechanisms ◽  
Localized Plastic Deformation

Shot peening is a common procedure used to improve the static and cyclic strength of metal components and for forming of thin walled components. The underlying mechanisms are localized plastic deformation, work hardening and the introduction of compressive stresses into the near-surface region. During the last decade we have been establishing damage-free shot peening processes for brittle materials such as ceramics. Based on these results we are now developing processes for peen-forming of ceramic components. This paper describes the first successful experiments aimed at shaping ceramic specimens using shot peening. Strips of different thicknesses, made of silicon nitride ceramic, were shot-peened using different shot sizes, peening pressures and coverage. The residual stress-depth distributions were determined using X-ray diffraction. Based on the experimentally determined stress states, the curvatures of the strips were calculated analytically and using Finite Element calculations (FEM). The results of the curvature measurements and calculations agree well.

Galvanised Sheets as Building Material

2014 ◽  
Vol 1020 ◽  
pp. 15-20 ◽  
Author(s):  
Janina Adamus ◽  
Monika Gierzyńska-Dolna ◽  
Wilhelm Gorecki ◽  
Piotr Lacki
Keyword(s):  
Corrosion Resistance ◽  
Civil Engineering ◽  
Zinc Coating ◽  
Key Factors ◽  
Forming Process ◽  
Factors Affecting ◽  
Steel Sheets ◽  
Steel Base ◽  
Structural Parts ◽  
The Relationship

Civil engineering uses steel as one of the basic structural materials. Sheets play an important role among the steel products. Although steel sheets are relatively cheap and have good mechanical and technological properties, low resistance against corrosion poses a fundamental weakness. A solution to this problem is the use of galvanised or organic-coated steel sheets. Galvanising can be carried out by hot dipping (single structural parts) or continuous galvanising: electrolytic and hot-dip galvanising (sheets and strips or long products, such as: wires or pipes).In the paper steel sheets used in the civil engineering as structural parts or wall and roof cladding are discussed. A special attention is paid to corrosion resistance of the steel sheets. Some results of corrosion tests is presented. The tests were aimed at determination the corrosion resistance of hot-dip and electrolytic galvanised sheets. The influence of the galvanising technology and the relationship between the degree of material deformation and susceptibility to corrosion are given. Coating thickness and kind of the applied galvanising technology is pointed as the key factors affecting the corrosion resistance of galvanised sheets. It is highlighted that during the forming process of galvanised sheets (bending, sheet-metal forming) the zinc coating deforms more than the steel base, so its thickness decreases, and therefore the corrosion resistance of the final product decreases, too.

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