Effect of viscosity on radial stress, drawing stress and drawing force in fluid assisted deep drawing process

Author(s):  
R. Uday Kumar ◽  
P. Ravinder Reddy ◽  
A.V. Sita Ramaraju
Author(s):  
Dietrich Bauer ◽  
Regine Krebs

Abstract For a deep drawing process some important controllable variables (factors) upon the maximum drawing force are analyzed to find a setting adjustment for these process factors that provides a very low force for the metal forming process. For this investigation an orthogonal array L18 with three-fold replication is used. To find the optimum of the process, the experimental results are analyzed in accordance with the robust-design-method according to Taguchi (Liesegang et. al., 1990). For this purpose, so-called Signal-to-Noise-ratios are calculated. The analysis of variance for this S/N-ratios leads to a mathematical model for the deep drawing process. This model allows to find the pressumed optimal settings of the investigated factors. In the following, a confirmation experiment is carried out by using these optimal settings. The maximum drawing force of the confirmation experiment does not correspond with the confidence interval, which was calculated by analysis of variance techniques. So the predicted optimum of the process does not lead to a metal forming process with very low deep drawing force. The comparison with a full factorial plan shows that there are interactions between the investigated factors. These interactions could not be discovered by the used orthogonal array. Thus the established mathematical model does not describe the relation between the factors and deep drawing force in accordance with the practical deep drawing conditions.


2015 ◽  
Vol 760 ◽  
pp. 379-384 ◽  
Author(s):  
Lucian Lazarescu ◽  
Ioan Nicodim ◽  
Dan Sorin Comsa ◽  
Dorel Banabic

In this study, the influence of the blank-holding force (BHF) on the drawing force (DF) in the deep-drawing process of cylindrical and square cups has been investigated experimentally. For this purpose, different constant and variable BHFs have been applied to AA6016-T4 aluminum alloy and DC04 steel sheets during the forming process. It has been observed that an increased constant BHF leads to an increase of DF. On the other hand, the variable BHF approach, in which the BHF decreases in six steps throughout the punch stroke, reduces the DF.


Author(s):  
Aarón Rivas Menchi ◽  
Hugo I. Medellín Castillo ◽  
Dirk F. de Lange ◽  
Pedro de J. García Zugasti

The deep drawing process has been widely used in the industry because it eliminates costly operations such as welding and machining. However, there are many parameters involved that affect the quality of the final products. One of the main parameters of the deep drawing process is the maximum deep drawing force (DDF) or drawing load, which is the maximum force required to perform a particular deep drawing operation. This maximum DDF is needed to define the required capacity of the press, and to calculate the deep drawing work and the process efficiency. Several analytical expressions to estimate the maximum DDF have been proposed in the literature, particularly for cylindrical parts. However, few research works have focused on analyzing the prediction performance of these expressions. In this paper, the performance of different analytical expressions to estimate the maximum DDF of cylindrical and rectangular parts, is evaluated and compared. Initially, several expressions proposed by different researches for the maximum DDF of cylindrical parts are presented. Then, these expressions are transformed into new expressions for the maximum DDF of rectangular parts by using different concepts of equivalency, such as the equivalent diameter concept. Finally, the prediction performance of all the expressions for both cylindrical and rectangular deep drawing is analysed and compared using experimental data from the literature. The performance is evaluated in terms of the prediction error. The results have suggested that the analytical expressions involving the largest number of parameters have a superior prediction performance than the analytical expressions involving less parameters.


2013 ◽  
Vol 789 ◽  
pp. 367-372 ◽  
Author(s):  
Susila Candra ◽  
I. Made Londen Batan ◽  
Agus Sigit Pramono ◽  
Bambang Pramujati

This paper presents the importance of simulation of metal flow in deep drawing process which employs an antilock brake mechanic system. Controlling the force and friction of the blank holder is imperative to assure that the sheet metal is not locked on the blank holder, and hence it flows smoothly into the die. The simulation was developed based on the material displacement, deformation and deep drawing force on flange in the radial direction, that it is controlled by blank holder with antilock brake mechanic system. The force to blank holder was applied periodically and the magnitude of force was kept constant during simulation process. In this study, the mechanical properties of the material were choses such that they equivalent to those of low carbon steel with its thickness of 0.2 mm. The diameter and the depth of the cylindrical cup-shaped product were 40 mm and 10 mm, respectively. The simulation results showed that the application of antilock brake mechanic system improves the ability to control the material flow during the drawing process, although the maximum blank holder force of 13000 N was applied. The optimum condition was found when the drawing process was performed using blank holder force of 3500 N, deep drawing force of 7000 N, friction coefficient of 0.25 and speed of punch stroke of 0.84 mm/sec. This research demonstrated that an antilock brake mechanic system can be implemented effectively to prevent cracking in deep drawing process.


2021 ◽  
Vol 11 (19) ◽  
pp. 9235
Author(s):  
Hussein Zein ◽  
Osama M. Irfan

Deep drawing is characterized by extremely complex deformation that is influenced by process characteristics such as die and punch shapes, blank shape, blank holding force, material properties, and lubrication. The optimization of the deep drawing process is a challenging issue due to the complicated functions that define and relate the process parameters. However, the optimization is essential to enhance the productivity and the product cost in the deep drawing process. In this paper, a MATLAB toolbox (Pattern Search) was employed to minimize the maximum deep drawing force (Fd-min) at different values of the operating and the geometrical parameters. As a result, a minimum deep drawing force chart (carpet plot) was generated to show the best combination of friction coefficients at the blank contact interfaces. The extracted friction coefficients guided the selection of proper lubricants while minimizing the deep drawing force. A finite element analysis (FEA) was applied through 3D model to simulate the deep drawing process. The material modeling was implemented utilizing the ABAQUS/EXPLICIT program with plastic anisotropy. The optimization results showed that the deep drawing force and the wrinkling decrease when compared with experimental and numerical results from the literature.


2011 ◽  
Vol 121-126 ◽  
pp. 1495-1499
Author(s):  
Tsu Hsiao Chu ◽  
Kuang Hua Fuh ◽  
Wei Ching Yeh

A ultrasonic vibration system with ram motion of two steps is developed to optimize the formability for thin workpiece at the end of forming. The deep drawing force and forming height can be predicted in view of optimizing the values of the working variables involved in the process parameters. A response surface methodology (RSM) based on design of experiments was used in order to minimize the forming force and maximum the forming height during the deep drawing process. Associated plots are shown to be efficient for a quick choice of the optimum values of the forming process parameters.


2015 ◽  
Vol 639 ◽  
pp. 33-40 ◽  
Author(s):  
Lucian Lazarescu ◽  
Ioan Nicodim ◽  
Dorel Banabic

In the deep drawing process, the blank-holding force (BHF) is an important process parameter affecting the energy consumption and the successful production of parts. In the present work, both experiments and finite element simulations have been conducted to investigate the influence of constant and time variable BHF on drawing force (DF) and thickness distribution in the deep drawing process of cylindrical and square cups. A finite element model was developed in the AutoForm software and validated with experiments. The developed model has been used for the simulation of deep drawing process of AA6016-T4 aluminum alloy sheet. The experimental and numerical results show that, using a variable instead of a constant BHF, the DF can be decreased in the expense of wall thickening.


Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3993
Author(s):  
Thanh Trung Do ◽  
Pham Son Minh ◽  
Nhan Le

The formability of the drawn part in the deep drawing process depends not only on the material properties, but also on the equipment used, metal flow control and tool parameters. The most common defects can be the thickening, stretching and splitting. However, the optimization of tools including the die and punch parameters leads to a reduction of the defects and improves the quality of the products. In this paper, the formability of the camera cover by aluminum alloy A1050 in the deep drawing process was examined relating to the tool geometry parameters based on numerical and experimental analyses. The results showed that the thickness was the smallest and the stress was the highest at one of the bottom corners where the biaxial stretching was the predominant mode of deformation. The problems of the thickening at the flange area, the stretching at the side wall and the splitting at the bottom corners could be prevented when the tool parameters were optimized that related to the thickness and stress. It was clear that the optimal thickness distribution of the camera cover was obtained by the design of tools with the best values—with the die edge radius 10 times, the pocket radius on the bottom of the die 5 times, and the punch nose radius 2.5 times the sheet thickness. Additionally, the quality of the camera cover was improved with a maximum thinning of 25% experimentally, and it was within the suggested maximum allowable thickness reduction of 45% for various industrial applications after optimizing the tool geometry parameters in the deep drawing process.


Author(s):  
Hamidreza Gharehchahi ◽  
Mohammad Javad Kazemzadeh-Parsi ◽  
Ahmad Afsari ◽  
Mehrdad Mohammadi

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