Simulation Study on Effect of Die Corner Radius in Single Stage Deep Drawing Process

IJSRD - International Journal for Scientific Research & Development| Vol. 4, Issue 04, 2016 | ISSN (online): 2321-0613

Simulation Study on Effect of Die Corner Radius in Single Stage Deep Drawing Process Arshad Ayyub1 Bharat S Kodli2 1 M Tech Scholar 2Professor 1,2 Department of Mechanical Engineering 1,2 P D A College Of Engineering, Gulbaraga-585102, Karnataka, India Abstract— The objective of this paper is to study the effect of die corner radius in deep drawing process simulation , and to determine the factors influencing the deep drawing process and analyzing the process by varying the die corner radius by keeping the following parameters Blank thickness, Punch radius, Drawing speed, and Co-efficient of friction constant , for this CAD Technique is combined with the process simulation to enable modeling using Uni-graphics, then simulation is performed using AFDEX Software., Aluminum alloy 6061 is used for deep drawing with initial diameter as 74mm.

Key words: Re, Uni Graphics, AFDEX, And BHF I. INTRODUCTION Deep drawing is a metal forming process in which a flat piece of sheet metal (i.e. blank) is transformed into a cylindrical form or shape .such transformation can be produced either in a single stage or in a sequence of operations, which depends on the drawing ratio.

Number of die(s) necessary to produce the desired product (cup) depends on "cup height over cup diameter" (h/d) ratio as shown in table 1.

If h/d < 0.75 If 0.75 < h/d < 1.5 If 1.5 < h/d < 3.0 If 3.0 < h/d < 4.5

then no. of draws = 1 then no. of draws = 2 then no. of draws = 3 then no. of draws = 4

Table 1: The relationship between the (h/d) ratio and number of draws The main variables involved in this process are 1) Blank thickness 2) Co-efficient of friction 3) Punch radius 4) Die corner radius 5) Blank holder force 6) Drawing speed A. Principal of Deep Drawing Process A flat work piece (blank) is formed into a cylindrical cup by forcing a punch against the center portion of the blank which is resting on the die shown in fig-1.

Fig. 2: A sequence of operation is shown in below II. SIMULATION In this project the die of different geometries and a blank thickness of same geometry where drawn using Unigraphics software and effort is made to simulate the deep drawing process by varying the die corner radius in order to find the optimized die corner radius using Afdex software, A cup in the form of cylindrical type is formed as a result of deep drawing. AFEDEX can predict blank holder force to assist in selecting appropriate BHF and also to develop and optimize the metal forming process, this predictions prolong the die life and thus increased productivity will give the user and company a great return on investment.

During the deep-drawing process, the blank is clamped between die and blank holder. The blank holder is to avoid the occurrence of wrinkling while the punch is forming the blank into the die cavity, blank material flows into die cavity. This effect is called material flow. It is important to control blank holder force to get defect-free components, to have a defect free component four values of Blank holder forces 700N, 800N, 900N and 1000N have been studied in this project.

III. METHODOLOGY The deep drawing process has been analyzed for different die corner radius and study is made to investigate and optimize the die corner radius, for this various iteration is performed. The material used for the analysis is AA6061 an Aluminum alloy.

The initial diameter is taken as 74mm, the deep drawing speed used here is 0.9m/sec, the co-efficient of friction between blank and die is taken has 0.125

Fig. 1:

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Simulation Study on Effect of Die Corner Radius in Single Stage Deep Drawing Process (IJSRD/Vol. 4/Issue 04/2016/281)

S/No 1 2 3 4 5 6

Dieradius 4.0 5.0 6.0 7.0 8.0 9.0

Damage(Mm) 3.3090e-001 2.48195e-001 2.36407e-001 2.36763e-001 2.08430e-001 2.11486e-001

Table 8: At BHF=900n Damage Values

Fig. 3: Component Punch diameter Blank diameter Blank thickness Punch fillet radius Friction coefficient Clearance die and punch Cup height Die corner radius

Dimensions(mm) 38 74 1 3 0.125 1 28 4, 5, 6, 7, 8 & 9

S/No 1 2 3 4 5 6

Die Corner Radius 4.0 5.0 6.0 7.0 8.0 9.0

Damage Values 3.41252e-001 2.88573e-001 2.53333e-001 2.40034e-001 2.29885e-001 2.13847e-001

Table 9: At BHF=1000n Damage Values A. Samples Are Presented In Figure 4 To 7

Table 2: Dimension specifications of the process component Al Mg Si Cu Fe Zn Mn Ti Cr

Composition by weight percentage (%) 98.6 1.2 0.8 0.4 0.7 0.25 0.15 0.15 0.35

Fig. 4: cup drawn with bhf-700N

Table 3: Material AA-6061 Composition Ultimate tensile strength Modulus of elasticity Poissonâ&#x20AC;&#x2122;s ratio Yield tensile strength Hardness,vickers Density

310 Mpa 68.9 Gpa 0. 33 276 Mpa 120 2.7 /gcc

Table 4: Physical properties of AA-6061 Material Drawing speed Friction coefficient Blank holder force

AA6061 0.9 m/sec 0.125 700, 800, 900,1000N

Table 5: Input parameter IV. RESULTS S/No 1 2 3 4 5 6

Die Corner Radius 4.0 5.0 6.0 7.0 8.0 9.0

Fig. 5: cup drawn with bhf-800N Damage(Mm) 3.34666e-001 2.72764e-001 2.65790e-001 2.50205e-001 2.41134e-001 2.14115e-001

Table 6: At BHF=700n Damage Values S/No 1 2 3 4 5 6

Die Corner Radius 4.0 5.0 6.0 7.0 8.0 9.0

Damage(Mm) 3.47310e-001 2.50839e-001 2.87036e-001 2.42355e-001 2.2988 E-001 2.30667e-001

Table 7: At BHF=800n Damage Values

Fig. 6: cup drawn with bhf-900N

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Simulation Study on Effect of Die Corner Radius in Single Stage Deep Drawing Process (IJSRD/Vol. 4/Issue 04/2016/281)

Fig. 7: cup drawn with bhf-1000N V. RESULTS AND DISCUSSION Wrinkling are the common defect found in metal forming process a large increase or decrease in BHF creates wrinkling and earring type quality problems in order to minimize this Simulations are carried out to find out the list damage value by varying the die corner radius to 4mm, 5mm, 6mm, 7mm, 8mm, and 9mm with a blank holder force of 700N, 800N, 900N, and 1000N. From figure 4-7, it is observed that wrinkling appears at BHF 700N and 800N, the blank holder force is increased at an incremental value of 100N at the value of 900N and a die corner radius of 8mm less wrinkling with minimum damage is found.

VI. CONCLUSION The effect of die corner radius on deep drawing process simulation has been done.

1) A decreased die corner radius creates wrinkling and earring type of problems 2) Because of the above problem, an optimum die corner radius was an important parameter to be found out from the simulation studies.

3) It has been found that a blank holder force of 900 N and an optimum die corner radius of 8mm give less wrinkling with minimum damage value.

4) The developed model is used to simulate any problems in deep drawing process for any material.

[2] Saani Shakil, Mostafa Hamed, and Abdessalem Chamekh “Single stage steel cup deep drawing analysis using finite element simulation”, International journal of engineering reaearch and technology, vol.4 issue 02, February-2015.

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[4] P V R Ravindra Reddy, G Chandra Mohan Reddy and T a Janardhan Reddy “ Studies on the effect of die corner radius and blank holding force on limit strains in deep drawing process” , International journal of engineering and material science, vol .19, PP. 24-30 February 2012, [5] Nikunj D.Patel, Bhavesh C. Patel, and Dr. Keyur J. Thakkarprocess “ A Review of deep drawing process and interdependency of its parameters”, International journal of engineering development and research,vol.2, PP. 327-3222 Issue-3, 2014 [6] T. S. Hemanth, Y. Arunkumar, and S. M. S, “Design and Manufacturing Simulation of Preform for Thread Rolling Operation,” Int. J. Mod. Eng. Res., vol. 5, no.

October, pp. 60–68, 2015.

[7] H. S. Thulasi, Y. Arunkumar, M. S. Srinath, and T. Rakshith, “Manufacturing Simulation for Determining The Influence of Process Parameters on Quality of Forgings,” in International Journal of Engineering Research & Technology (IJERT), NCERAME, 2015, pp. 146–151.

[8] ASM Metals Handbook Volume 14, Forming and Forging.

ACKNOWLEDGEMENT The authors are grateful to the Department of Production Engineering, Department of Mechanical Engineering, P D A College of Engineering, Gulbarga, for extending the facilities and support during study. The author expresses special gratitude to his guide Prof. Bharat .S. Kodli his inspiration, guidance, constant supervision, direction and discussions in successful completion of the project.

REFERENCES [1] Kopanathi Gowtham, K.V.N.S. Srikanth and K.L.N. Murty “Simulation of the effect of die corner radius on deep drawing process”, International journal of applied research in mechanical engineering, vol.2 issue-1, 2012.

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