scholarly journals Mathematical Modeling and Analysis of Hoop Stress in Hydroforming Deepdrawing of n-sided Polygonal Cup

2020 ◽  
Vol 9 (8) ◽  
pp. 1011-1014
Keyword(s):  
Deep Drawing ◽  
Hoop Stress ◽  
Outer Side ◽  
Drawing Process ◽  
Analytical Evaluation ◽  
Punch Force ◽  
Deep Drawing Process ◽  
Modeling And Analysis ◽  
Uniform Deformation ◽  
Hoop Stresses

The main objective of this paper presents the analytical evaluation and mathematical modelling of hoop stresses of aluminium 7075 alloys in hydro forming deep drawing of n-sided polygonal cup. It is very important to find the magnitude of these stresses generated within the flange region during the deep drawing process for various n-sided polygonal cups. In the flange region two types of stresses will be generated. When is radial tensile stress, it is taking place radially outward direction from the side of the cup to outer side of the blank material. and other is hoop stress it is compressive. It is perpendicular to the radial lines drawn from the job axis to the side of the blank. It is also parallel or tangential to the blank circumference. These two stresses will be generated within the blank material by the application of punch force.. As compared to the conventional deepdrawing process, hydroforming is very convenient. uniform deformation of the blank taking place throughout out the process

Effect of Geometries of Die/Blank Holder and Punch Radii in Angular Deep-Drawing Dies on DP Steel Formability

2015 ◽  
Vol 813-814 ◽  
pp. 269-273 ◽  
Author(s):  
P. Venkateshwar Reddy ◽  
S. Hari Prasad ◽  
Perumalla Janaki Ramulu ◽  
Sirish Battacharya ◽  
Daya Sindhu Guptha
Keyword(s):  
Deep Drawing ◽  
Thickness Distribution ◽  
Frictional Coefficient ◽  
Drawing Ratio ◽  
Drawing Process ◽  
Dp Steel ◽  
Punch Force ◽  
Blank Holder ◽  
Deep Drawing Process ◽  
Drawing Dies

In recent days deep-drawing is one of the most important methods used for sheet metal forming. The geometries of die/blank holder and punch are one of the parameters for deep-drawing. This paper presents an attempt to determine the effect of different geometries of die/blank holder, punch radii and blank holding force on deep drawing process for the formability of DP Steel of 1mm sheet. The numerical simulations are performed for deep drawing of cylindrical cups at a constant frictional coefficient of 0.12 and different blank holding forces of 10, 15 and 20kN are used. For numerical simulation PAM STAMP 2G a commercial FEM code in which Hollomon’s power law and Hills 1948 yield’s criterion is used. The die/blank holder profile used with an angles of α=0°, 12.5°, 15° and die/punch profile with a radii of R= 6 and 8mm were simulated to determine the influence of punch force and thickness distribution on the limit drawing ratio. The aim of this study is to investigate the effect of tool geometries on drawability of the deep-drawing process.

scholarly journals EFFECT OF BLANK RADIUS ON RADIAL STRESSES IN HYDROFORMING DEEP DRAWING PROCESS

2012 ◽  
pp. 231-236
Author(s):  
R.UDAY KUMAR
Keyword(s):  
Viscous Fluid ◽  
Deep Drawing ◽  
Castor Oil ◽  
Radial Direction ◽  
Frictional Resistance ◽  
Shear Stresses ◽  
Hydraulic Pressure ◽  
Drawing Process ◽  
Punch Force ◽  
Deep Drawing Process

This paper presents evaluation and effect of blank radius on radial stresses through mathematical formulations in hydroforming deep drawing process using castor oil medium. Hydraulic pressure can enhance the capabilities of the basic deep drawing process for making cups. In hydroforming deep drawing process, applying the hydraulic pressure on blank periphery in radial direction. It is obtained through the punch movement within the fluid chamber, which is provided in punch and die chambers. These two chambers are connected with the bypass path and it is provided in the die. During the process punch movement within the fluid chamber the pressure is generated in fluid and it is directed through the bypass path to blank periphery, the fluid film is created on the upper and lower surfaces of the blank and subsequently reduces frictional resistance and is to reduce tensile stresses acting on the wall of the semi drawn blank. The blank is taking at centre place in between blank holder and die surface with supporting of high pressurized viscous fluid. The radial stresses are produced in the blank in radial direction due to punch force applied on it, the shear stresses acted by viscous fluid on the both sides of blank, so apply viscosity phenomenon to this analysis. The radial stresses are determined in terms of viscosity of castor oil, blank geometry and process parameters for magnesium alloys.

FE simulation study of deep drawing process of SUS304 cups having no delayed cracks under enhanced blank holding force

2019 ◽  
Vol 234 (1-2) ◽  
pp. 84-94 ◽  
Author(s):  
Chin Joo Tan ◽  
Afshin Aslian
Keyword(s):  
Wall Thickness ◽  
Deep Drawing ◽  
Circumferential Stress ◽  
Wall Thickening ◽  
Drawing Process ◽  
High Concentration ◽  
Deep Drawing Process ◽  
Blank Holding Force ◽  
Force Range ◽  
Hoop Stresses

In the experiment, delayed cracks in deep drawing processes of metastable stainless steel SUS304 cylindrical cups were prevented using elevated blank holding force aided by nanolubrication. Besides tensile residual hoop stresses, the elimination of the cracks was also attributed to the change in wall thickening profile along the wavy cup edges. The wall thickening is a result of the high circumferential stress acting in the flange, leading to the high concentration of deformation-induced martensite and high risk of cracks. The amount of increase in wall thickness in the valleys along the edge during the deep drawing process was higher than the peaks at low blank holding force range due to shorter heights. Therefore, the portions of blank equivalent to the valleys were subject to higher holding force during the process, resulting in decrease in degree of wall thickening with increase in height for blank holding force up to 25 kN. However, the wall thickening and the height increased at blank holding force of 28 kN due to the same amount of increase in wall thickness in both valleys and peaks, resulting in a larger contacting area and lower holding force. Therefore, the wall thickness in the valleys sharply increased, and the formation of the cracks persists. Within the crack-free range, that is, from 29 to 31 kN, both the heights and wall thickening decreased. The decrease in frictional force by means of the nanolubrication has facilitated the flow of material into the die, resulting in lower cup height. It also facilitated the flow of materials away from the thick valley regions under the high pressure, resulting in significant decrease in degree of wall thickening. The cracks were prevented. The amount of compression at blank holding force of 32 kN was insufficient to suppress the increase in wall thickening in valleys, resulting in the formation of the cracks again.

scholarly journals Simulation and Analysis of Deep Drawing Process of the Functionally Graded Sheet

2019 ◽  
Vol 3 (1) ◽  
pp. 1-8
Author(s):  
Davood Hashempoor
Keyword(s):  
Deep Drawing ◽  
Functionally Graded ◽  
Drawing Process ◽  
Governing Equations ◽  
Graded Materials ◽  
Punch Force ◽  
Deep Drawing Process ◽  
Exponential Law ◽  
Abaqus Software ◽  
Good Agreement

In this paper, deep drawing process of functionally graded sheet is investigated analytically and using finite element method. Using equations for deep drawing of isotropic sheets and governing equations of functionally graded materials, equations for deep drawing of functionally graded sheets are derived. Mechanical properties of the functionally graded sheet vary through the thickness of it according to the exponential law distribution. Punch force and axial stresses at the wall are calculated by this analytical method. Also, using this force in abaqus software, axial stresses at the wall are determined. The results of two methods were compared with each other and good agreement was obtained.

scholarly journals Effect of Tool Geometry Parameters on the Formability of a Camera Cover in the Deep Drawing Process

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3993
Author(s):  
Thanh Trung Do ◽  
Pham Son Minh ◽  
Nhan Le
Keyword(s):  
Deep Drawing ◽  
Thickness Distribution ◽  
Metal Flow ◽  
Sheet Thickness ◽  
Side Wall ◽  
Tool Geometry ◽  
Drawing Process ◽  
Nose Radius ◽  
Deep Drawing Process

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.

Blank shape optimization in the deep drawing process by sun method

2021 ◽  
Author(s):  
Hamidreza Gharehchahi ◽  
Mohammad Javad Kazemzadeh-Parsi ◽  
Ahmad Afsari ◽  
Mehrdad Mohammadi
Keyword(s):  
Shape Optimization ◽  
Deep Drawing ◽  
Drawing Process ◽  
Deep Drawing Process ◽  
Blank Shape Optimization ◽  
Blank Shape

Production of Tapered Cups by Sequential Deep Drawing of Sheet Metals Using Drawn Cups as a Part of Punch

1993 ◽  
Vol 115 (2) ◽  
pp. 224-229 ◽  
Author(s):  
K. Yamaguchi ◽  
K. Kanayama ◽  
M. H. Parsa ◽  
N. Takakura
Keyword(s):  
Deep Drawing ◽  
Drawing Ratio ◽  
Drawing Process ◽  
Sheet Metals ◽  
Deep Drawing Process ◽  
Drawing Method

A new deep drawing process of sheet metals is developed to facilitate small-lot production of deep cups with large drawing ratio. In this process, unlike the conventional deep drawing method, a few drawn cups are always stacked on the punch and used as a part of punch for the subsequent deep drawing of a given blank. Before drawing a new blank, a drawn cup which is in contact with the punch is stripped off. The repetition of such stripping and drawing operations makes it possible to carry out both the first-stage drawing and the subsequent slight redrawings in one drawing operation using only one pair of punch and die. In this paper, this new deep drawing process is applied to the production of tapered cups and the main feature of the process is shown.

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