A new upper bound solution for the analysis of the twist extrusion process with an elliptical die cross-section

2009 ◽  
Vol 223 (9) ◽  
pp. 1975-1981 ◽  
Author(s):  
Salehi M Seyed ◽  
S Serajzadeh
Keyword(s):  
Upper Bound ◽  
Extrusion Process ◽  
Die Design ◽  
Design Parameters ◽  
Element Analysis ◽  
Die Geometry ◽  
Proposed Model ◽  
Twist Extrusion ◽  
Upper Bound Technique ◽  
Highly Strained

The twist extrusion process is a rather new route to produce highly strained materials. In this process, severe plastic deformation is applied by large shear strains. In this regard, prediction of materials behaviour and extrusion pressure is of importance to die designers and engineers. In this article, utilizing an admissible velocity field together with the upper bound technique, the required energy for twist extrusion is predicted. The proposed model is capable of considering the effect of various parameters such as die geometry and friction conditions. In addition, the model anticipates the critical die design parameters. To verify the proposed model, the predictions are compared with the results of a finite-element analysis and reasonable consistency is observed.

scholarly journals Die Design for Extrusion Process of Titanium Seamless Tube Using Finite Element Analysis

Metals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1338
Author(s):  
Byung-Jin Choi ◽  
In Yong Moon ◽  
Young-Seok Oh ◽  
Seong-Hoon Kang ◽  
Se-Jong Kim ◽  
...  
Keyword(s):  
Finite Element ◽  
Extrusion Process ◽  
Maximum Principal Stress ◽  
Die Design ◽  
Von Mises Stress ◽  
Design Parameters ◽  
Forming Process ◽  
Element Analysis ◽  
Corner Radius ◽  
Von Mises

In this paper, the extrusion process of titanium seamless tubes was studied using several finite element (FE) analyses. First, the finite element result was compared with experimental extrusion data acquired to validate the current analysis. Then, the effect of design parameters of the die shape was numerically analyzed using commercial FE software, Forge NxT, for the metal forming process. Elastic FE analyses were also conducted for dies to analyze the maximum principal stress that affects the early fracture of dies during the extrusion process and the maximum von Mises stress that causes the severe deformation of dies. Consequently, the effect of the corner radius at the exit and land length on the extrusion load and die stress is negligible compared to that of the corner radius at the entrance and die angle. Finally, we suggested a die angle of 60° and a corner radius at the die entrance between 10 and 15 mm as an optimal design for the current extrusion process.

scholarly journals EFFECTS OF GUIDING CHAMBER ON WELDING PRESSURE IN HOLLOW EXTRUSION DIE DESIGN OF AA7075

2018 ◽  
Vol 54 (5A) ◽  
pp. 191
Author(s):  
Do Anh Tuan
Keyword(s):  
Aluminum Alloy ◽  
Extrusion Process ◽  
Die Design ◽  
Design Parameters ◽  
Element Analysis ◽  
Suitable Material ◽  
Hollow Section ◽  
Extrusion Die ◽  
Welding Pressure ◽  
Aluminum Alloy Tube

Porthole die extrusion has a great advantage in the forming of hollow section of aluminum alloy tube. This paper aims at the development of an extruding seam square tube of AA7075 high strength aluminum alloy. In order to increase the welding pressure of the hollow AA7075 tube in extrusion process, a special die feature has been created. Several different proportions of chamber structure in outlet of extrusion die have been designed. The finite element analysis software DEFORM 3D to analyze various design parameters on the load – displacement and the welding pressure have been studied. In this study, a different high proportion in material guiding chamber has been defined. The results showed that if a suitable material guiding chamber has been built then welding pressure can be increased rapidly. When the ratio of chamber height and length is 2:1 the increased welding pressure is the best.

An upper bound solution for twist extrusion process

2014 ◽  
Vol 20 (5) ◽  
pp. 825-834 ◽  
Author(s):  
M. Seyed Salehi ◽  
N. Anjabin ◽  
H. S. Kim
Keyword(s):  
Upper Bound ◽  
Extrusion Process ◽  
Bound Solution ◽  
Upper Bound Solution ◽  
Twist Extrusion

Closed-Die Forging of Gear-Like Elements

1998 ◽  
Vol 120 (1) ◽  
pp. 34-41 ◽  
Author(s):  
A. El-Domiaty ◽  
M. Shabara ◽  
M. Al-Ansary
Keyword(s):  
Upper Bound ◽  
Pure Aluminum ◽  
Experimental Results ◽  
Frictional Stress ◽  
Die Geometry ◽  
Die Forging ◽  
Closed Die Forging ◽  
Theoretical Predictions ◽  
Upper Bound Technique ◽  
Forging Die

Closed die forging of spur gears is investigated using the slab method and the upper bound technique. The tooth regions are approximated by prismatic rectangular sections. The velocity field comprising three unit deformation regions is used. A constant frictional stress between workpiece and forging die is assumed. The average punch pressure normalized by the flow stress of the gear material is determined theoretically and compared with experimental results. The experimental work is carried out on a commercial pure aluminum (Al 1100) at room temperature. The forging process is carried out using one die geometry without using any additional blocker (preform) dies. The theoretical predictions of forging pressures using slab and upper bound methods agree fairly well with the experimental results.

Study on the Guiding Chamber Effect on Welding Pressure in Hollow Extrusion Die Design

2010 ◽  
Author(s):  
Quang-Cherng Hsu ◽  
Ping-Hsun Tsai
Keyword(s):  
Aluminum Alloy ◽  
Flow Behavior ◽  
Metal Flow ◽  
Die Design ◽  
High Yield ◽  
Design Parameters ◽  
Element Analysis ◽  
Suitable Material ◽  
Extrusion Die ◽  
Welding Pressure

In order to increase the welding pressure of the hollow Al7075 tube in extrusion process, a special die feature has been created. Several different proportions of chamber structure in outlet of extrusion die have been designed. The finite element analysis software DEFORM 3D to analyze various design parameters on the load–displacement and the welding pressure have been studied. Comparing to 6000 series, 7000 series aluminum alloy have good material properties, including excellent strength and toughness especially for hollow aluminum extrusion products in terms of Al7075. However, in extruded hollow aluminum alloy products, the industry’s common use is 6000 series material, except for indirectly extruded seamless pipe, Al7075 can be found. This is because of less welding pressure can be provided by using the traditional die structures in Al7075 hollow products. Therefore, to use the directly extruded seam tube of Al7075 in high-yield and high-quality, to increase the welding pressure and improve the quality of welding products becomes a very important issue. In this study, a different high proportion in material guiding chamber has been defined. The same angle both on the exit of female die and the bearing of male die which can be integrated into a material guiding chamber has been designed. Therefore, the welding pressure can be increased due to the change of metal flow behavior that is after a complete fill in material guiding chamber, and then metal can flow out of die bearing surface. The results showed that welding pressure can be increased rapidly if a suitable material guiding chamber has been built. Among them, the ratio of chamber height and length is 2:1; the increased welding pressure is most significant.

scholarly journals Numerical Analysis of a New Nonlinear Twist Extrusion Process

Metals ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 513 ◽  
Author(s):  
Tuncay Yalçinkaya ◽  
Ülke Şimşek ◽  
Hiroyuki Miyamoto ◽  
Motohiro Yuasa
Keyword(s):  
Plastic Strain ◽  
Production Efficiency ◽  
Computational Study ◽  
High Strength ◽  
Extrusion Process ◽  
Linear Arrangement ◽  
Die Geometry ◽  
Ultrafine Grained ◽  
Twist Extrusion ◽  
The Many

Severe plastic deformation (SPD) can produce ultrafine grained (UFG) and nanocrystalline (NC) materials by imposing intense plastic strain. One of the many options for inducing large plastic strains is to pass the material through a torsional/twist extrusion. The high-strength materials fabricated by SPD has no limit in dimension, and they can even be applied to load-carrying structural materials. Even though the method is quite successful, the industrial transfer has been limited so far because of low production efficiency and high cost. To remedy such difficulties, a new torsional extrusion process called nonlinear twist extrusion (NLTE) is introduced in this study, which has been designed based on two principles; (1) linear arrangement of the production line and (2) effective die geometry resulting in higher and more homogeneous plastic strain evolution which would give better grain refinement. The initial computational study of the designed geometry for the new extrusion process is addressed in the current study. The obtained results are discussed in detail with respect to conventional extrusion process, which is referred to as linear twist extrusion (LTE). The method is expected to offer a great potential for industrial use.

Die Design of a Back Panel for a PDP TV Using 3-D Elasto-Plastic Finite Element Analysis

2008 ◽  
Vol 575-578 ◽  
pp. 322-327
Author(s):  
Dong Gyu Ahn ◽  
Hyun Soo Moon
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Optimum Design ◽  
Research Work ◽  
Die Design ◽  
Design Parameters ◽  
Element Analysis ◽  
Corner Radius ◽  
Blank Sheet ◽  
Back Panel

The objective of this research work is to design optimally dies and the blank sheet for manufacturing of the back panel of a PDP TV. The influence of design parameters of the dies and the blank sheet on the formation of wrinkling in the upper trimming area of the stamped part has been quantitatively investigated through three-dimensional elasto-plastic finite element analysis. The corner radius of the upper trimming area of the die and the blank gap, which is the distance from the outer line of the blank holder to that of the blank, have been chosen as design parameters to remove wrinkling associated with a stamping part in a upper trimming area. From the results of the analyses, it has been shown that a product without wrinkles and skid lines can be manufactured when the corner radius is 8 mm and the blank gap is 60 mm. Several stamping tests have been performed using the manufactured die set and the blank sheet according to the proposed optimum design. From the results of the stamping tests, it has been shown that a back panel of the PDP TV can be successfully manufactured using the proposed optimum design condition.

An Analytical study of Optimal Die Design of Elliptic Tube

2013 ◽  
Vol 1 (1) ◽  
pp. 43-59
Author(s):  
Muthanna H. S.
Keyword(s):  
Friction Factor ◽  
Upper Bound ◽  
Die Design ◽  
Relative Deformation ◽  
Area Reduction ◽  
Variable Friction ◽  
Die Profile ◽  
Upper Bound Technique ◽  
New Equation ◽  
Reduction Of Area

In this study, die profile of the elliptic tube extrusion is analysis to predict the optimum die design by using upper bound theory. Developed manner in determining the relative extrusion power by dividing the extrusion die for different sector and calculate the relative deformation power of each sector under different condition which are reduction of area, friction factor and relative die length. The study predicts a new equation for determining the optimum die length with taking in the count the effects of those variables.  The surface of the die is generated by an envelope of straight lines drawn from the points on the perimeter at the entry section to corresponding points at exist of the die. An upper bound technique based on the kinematically admissible velocity field is used to determine the forming stress. A complex program built in Visual Fortran V5.0 used to calculate relative extrusion power with variable friction factor (relative optimum extrusion power for values of  reduction area are changed from 52.6% at area reduction equals to 0.15 to 82.8% at area reduction equals to 0.4). ANSYS program is used to compare the behavior and values of  relative extrusion stress for  optimum relative die length at constant reduction of area (R.A.=25%). The results are compared with other papers theoretical and experimental results are found to be in a very good agreement.

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