The main objectives are as follows: 1.To develop a model for the automotive component “Control Arm” 2.To analyse the simulation trials 3.To optimize the Stress

1. A
Presentation on
Die Design Optimisation and Stress Analysis
of Control Arm by Simulation method
Supervised By:
Dr. N. K. Singh
Professor, Department of Forge Technology
Presented by:
Kundan Kumar
M.Tech (FFT)
FF16M21
National Institute of Foundry and Forge Technology
Hatia, Ranchi-834003

2. Introduction

3. Forging
• A manufacturing process involving shaping of metals under the localised compressive
forces
• Metals undergo plastic deformation by applying loads above yield strength but below
Ultimate Tensile Strength
• Forged components are stronger than castings, because of the associated grain flow and
directional properties
• Types of forging
1. Based upon input temperature
• Hot forging
• Cold forging
2. Based upon die shape
• Open die forging
• Closed die forging

4. Closed Die Hot Forging
• Shaping of hot metals within the cavity formed by two dies.
• The cavity formed by both the die is an replica of the final shape of the forging.
Also called impression forging.
• Force required for deformation is applied by forging presses or hammers.
• Excess metal is squeezed out of the die cavities; forming what is referred to as
"flash“.
• The flash cools more rapidly than the rest of the material; this cool metal is
stronger than the metal in the die, so it helps prevent more flash from forming.
• This also forces the metal to completely fill the die cavity.

5. Factor Affecting Die Filling
 Forging temperature
 Forgeability and flow strength
 Friction and lubrication
 Die temperature
 Shape and size factor

6. DEFORM-3D
 The one of the best method for analysis of closed die forging as it reduces human effort and
cost in many ways
 It is an efficient tool for studying metal flow and is flexible so that one can examine different
types of parameters and process conditions for a particular process
 Variation in temperature, heat transfer, flow stress, strain, strain rate etc. at any localised
point all are included in FEM analysis, which makes it very close to the actual process done in
real life
 One such FEM software is DEFORM-3D is used for the present work
 Three fundamental segment in the module are
1. Pre- processor 2. Processor 3. Post- processor

7. Objective and Scope of the
Present Work

8. Objective of the Present Work
• The main objectives of present work are as follows:
1. To develop a model for the automotive component “Control Arm”
2. To analyse the simulation trials
3. To optimize the Stress

9. A Brief Description of Control Arm
 “U” shaped automotive component
 Control Arm is to keep the suspension of a motor vehicle from
uncontrollably swerving when the road conditions are not smooth
Figure 1: Control Arm in an automotive suspension system

10. Methodology

11. Selection of Component
Preparation of 3D Model of the
Component
Conversion of Component Drawing into
Forging Drawing
Design of Dies
Calculation of Important data prior to Simulation trials for
Optimisation
Simulation trials for Optimisation done be varying certain
Parameters of Design
Development of Final Model of the Component
for Forging

12. Steps for Die Design and Development of
Forging Drawing
a) Providing different allowances to develop the forging drawing.
b) Determination of parting plane and the axis in the product design is the factor
that reflects the design skill.
c) The next step is to give the required draft angle. If the shape of the job facilitates
the use of natural draft, it will be better.
d) The next step is to give the required fillet and corner radii, sharp corner radii
must be avoided as they weaken both the dies and finished forgings.
e) Next step is to work out the flash and gutter design, based on hammer, press or
up-setters etc.
f) Selection of suitable equipment e.g., different type of press or hammers.

13. Experimental Procedure

14. Component drawing of the Control Arm and
Development of 3D Model
Figure 2: Component Drawing of the Control Arm
Figure 3: 3D Model of Control Arm

15. Development of Forging Drawing
1. Selection of parting line
2. The 3D model of forging drawing of control arm is generated in CATIA V5R19 taking
consideration of the following allowances
Machining allowance 1.5 mm per 200 mm of surface
Draft angle 5ᴼ (internal) and 3ᴼ (external)
Fillet and Corner radii 3mm
Figure 4: Selection of Parting line

16. Development of Forging Drawing
Figure 5
Figure 6

17. Design of Flash Land and Gutter

18. Die Block Size Calculation
• Width of die block (W):
W ≥ width forging + 1.5× (depth of right + left side impression)
≥ 112 mm
• Length of die block (L):
L ≥ length forging + 1.5× (depth of right + left side impression)
≥ 113 mm
• Calculation of height (H):
H ≥ 2-3 times of heigh
≥ 2.5×22 = 55mm

19. Properties of Billet Material
Material selected AISI-1016
Young’s modulus 2x105MPa
Poisson’s Ratio 0.29
Tensile Ultimate Strength 500 M Pa
Tensile Yield Strength 320 M Pa
Density 7860 kg/m3

20. Properties of Die Material
S. No Element Content
1 Carbon, C 0.32-0.45
2 Molybdenum, Mo 1.10-1.75
3 Silicon, Si 0.80-1.20
4 Vanadium, V 0.80-1.20
5 Chromium, Cr 4.75-5.50
6 Nickel, Ni 0.3
7 Copper, Cu 0.25
8 Manganese, Mn 0.20-0.50
9 Phosphorus, P 0.03
10 Sulfur, S 0.03
S. No Property Magnitude
1 Ultimate Tensile
Strength
1200 -1590 M pa
2 Yield strength
1000-1380 M pa
3 Reduction of C/S
area
50.00%
4 Modulus of elasticity
215 G Pa
5 Poisson's ratio
0.27-0.30
Die material selected for this experiment is AISI H13 and has following properties.

21. Parameters for Initial Design of Dies
S.No Parameters Value
1 Machining allowance (IS 3469) 1.5 mm /200mm of surface
2 Draft 3 to 50
3 Fillet and corner radius (For finisher) 5 mm
4 Flash thickness 1.6mm
5 Flash width 7.5 mm
6 Gutter thickness 4.8 mm
7 Gutter width 22.5 mm
8 Volume of forging 66157.76081 mm3
9 Density 7860 Kg/m3
10 Net Weight 0.336 Kg

22. 3D Model of Upper and Lower Die
Figure 8: 3D Model of Upper die Figure 9: 3D Model of Lower die

23. Billet/ Stock Size Calculation

24. Load Calculation

25. Parameter Matrix for Optimisation Purpose
Flash thickness Flash width Billet
temperature
Die
temperature
Friction
coefficient
1.6 7.5 1150 200 0.4
2.0 8.0 1200 250 0.5
2.5 8.0 1250 300 0.6

26. Input Data For Simulation
Material of Billet AISI-1016
Material of Die H-13
Billet Temperature 1100ºC, 1100ºC, 1200ºC
Die Temperature 300°C, 250°C, 200°C,150°C
Press capacity and specifications 1000 Ton Mechanical press (Crank press)
Displacement: 254mm
Strokes/ sec : 1.4167
Coefficient of friction 0.4, 0.5
Number of meshes in preform 40000
Number of meshes in dies 10000

27. Experimental Results

28. Forging Load and Die Filling at Different
Levels of Input Parameters
Run Parameters Load (in
tons SI)
Effective
Stress (Mpa)
Principal Stress
(Mpa) Die fillingFlash
thickness
(in mm)
Flash
width
(in mm)
Billet
temperature
(in ᴼC)
Die
temperature
(in ᴼC)
1 1.6 7.5 1200 250 325 360 349 COMPLETE
2 1.6 7.5 1200 200 322 366 365 COMPLETE
3 1.6 7.5 1100 150 485 498 459 UNDERFILL
4 1.6 7.5 1150 200 420 876 378 UNDERFILL
5 1.6 8.0 1150 250 362 453 443 COMPLETE
6 1.6 8.0 1250 250 213 317 299 COMPLETE
7 1.6 8.0 1250 200 301 306 306 COMPLETE
8 1.6 8.0 1200 200 309 335 329 COMPLETE
9 1.6 8.0 1200 250 306 393 337 COMPLETE
10 1.6 8.0 1250 200 305 402 331 COMPLETE

29. 11 1.6 8.0 1150 250 322 396 387 COMPLETE
12 1.6 8.0 1150 200 326 321 406 UNDERFILL
13 1.6 8.0 1200 150 418 345 364 COMPLETE
14 1.6 8.0 1150 150 260 379 394 COMPLETE
15 1.6 8.5 1200 250 347 729 402 COMPLETE
16 1.6 8.5 1100 150 201 301 499 UNDERFILL
17 1.6 8.5 1250 250 372 702 672 COMPLETE
18 2.0 7.5 1100 200 325 340 332 COMPLETE
19 2.0 7.5 1100 250 367 407 339 COMPLETE
20 2.0 7.5 1100 300 260 700 348 UNDERFILL
21 2.0 7.5 1200 200 315 374 432 COMPLETE
22 2.0 7.5 1200 250 222 554 332 COMPLETE
23 2.0 7.5 1250 200 435 337 391 COMPLETE
24 2.0 7.5 1250 250 398 298 334 COMPLETE
25 2.0 8.0 1100 200 360 321 421 COMPLETE
26 2.0 8.0 1250 250 316 326 337 COMPLETE
27 2.0 8.0 1150 150 350 330 361 UNDERFILL
28 2.0 8.0 1150 200 375 554 532 COMPLETE

30. 29 2.5 8.0 1250 250 486 544 456 UNDERFILL
30 2.5 8.0 1150 200 369 356 332 COMPLETE
31 2.5 8.0 1200 200 322 380 360 COMPLETE
32 2.5 8.0 1250 300 326 310 325 UNDERFILL

31. Results analysis

32. 1. Out of 32 simulations, underfilling is
observed in 7 runs.
2. The underfilling has majorly occurred in
the arms of the Control arm, in the manner
as shown in figure. (Run no. 3 and 4)
3. High width to thickness ratio of the section
leads to frictional restriction to the lateral
flow of metal.
4. Chilling of metal during forging also
contributes to the underfilling.
Figure 11: Simulation trial no. 4
Figure 10: Simulation trial no. 3

33. 5. Forging load is low for all runs where flash thickness is 2mm while it is higher for
those where flash thickness is 1.6mm.
6. Load decreases by 50 tons on a increase in flash thickness from 1.6mm to
2mm.(Trail No. 30 and 31).
7. A higher load is required in the transverse direction; when the excess material tries
to escape from the die cavity.
8. A very high value of flash thickness is also not desired, as it can cause incomplete
filling of the die. All of the underfilling that has occurred are when flash thickness is
either 1.6mm or more then 2mm except simulation 16 where flash thickness 2mm.
9. Higher flash thickness can also cause difficulties in trimming stage and consumption
of a greater amount of input material (billet) for the same size of the finished
product.

34. 11. No defects has been observed in simulation trials where dies have flash thickness equal
to 2.0mm, except in trial no. 20 And 27.
12. The main reason behind this is the low billet and die temperatures which result in high
flow stress values.
Figure 12: Temperature
Distribution of
Simulation no. 18

35. 13. Forging load is reduced drastically with the increase in input billet temperature, as flow
stress, which reduces with increase in temperature.
14. A decrease in billet temperature by 50ᴼC (simulation no 30 and 31) an increase in load by 50
tons is observed.
15. Most of the underfilling has been observed when billet temperature is low, i.e., 1100ᴼC.
Or die temperature is 150ᴼC Simulation no 14 are exceptions.
16. Too high temperature combined with larger flash thickness (2mm in this case) cannot
generate the required restriction to the flow of metal through flash land to fill the die.

36. 17. A low die temperature causes loss of heat especially in the area around arms of control
arm, which causes not only high effective stress but also underfilling.
18. For flash thickness 2mm, most of the under has occurred when die temperature is lower
than 300ᴼC.
19. Flash width also effects the forging load in a manner that an increase in flash width
causes load to increase.
20. This happens because a wider flash creates frictional resistance to the metal flow, which is
good for proper filling of die, but higher loads are required for escape of excess material
after complete filling of die cavity.

37. 20. Simulation for optimum load and stress: simulation no. 7
Parameters of simulation no. 7:
Result:
Load = 301 tons
Die filling = Completely filled
Effective Stress = 306 M Pa Principal Stress = 309 M Pa
Flash thickness Flash Width Billet temperature Die temperature Friction
coefficient
2.0 8 1250 250 0.4

38. Figure 13: Simulation no. 7 with load vs. time plot Figure 14: Optimum Stress

39. Figure 14: Stepwise simulation of trial no. 19

40. 20. Simulation for optimum load: simulation no. 8: Next Minimum Forging
Load
Parameters of simulation no. 8:
Result:
Load = 309 tons
Die filling = Completely filled
Effective Stress = 335 Mpa Principal stress =329 MPa
Flash
thickness
Flash width Billet
temperature
Die
temperature
Friction
coefficient
1.6 8.0 1250 250 0.4

41. 22. It is ovserved by Increasing the flash thickness 1.6 to 2.0 and flash width 7.5 to 8.0 gives complete
die filling and load and stress are also reduced
Figure 15: effective stress of 3(1) And Principal Stress of 3(1)Figure 16: Simulation no. 3(1)

42. Conclusion

43. 1. Different parameters/ process variables of simulation trial no. 19, upon which a model of
Control arm can be developed, are mentioned in following table.
Draft angle 5ᴼ (external) and 3ᴼ (internal)
Fillet and corner radii 3mm
Machining allowance 1.5 mm/ 200mm of surface
Flash thickness 2 mm
Flash width 8 mm
Billet temperature 1200ᴼC
Die temperature 250ᴼC
Optimum Forging load 311 tons
Billet weight 0.440 kg
Effective stress 306 MPa

44. 2. Finite element method is quite suitable for analysing complex
metal forming characteristics in a closed die hot forging process.
3. Using the FE method, other phenomena associated with metal forming,
such as heat generation due to deformation, heat transfer etc. can be
coupled with the basic deformation analysis.
4. The die filling prediction in terms of contact element behaviour is found
useful in real life situation.
5. The billet temperature, flash thickness, flash width and die
temperature are found to have a significant effect on the forging load.
6. Among the four, flash thickness is found to be the most significant
parameter followed by the temperature of the input billet, flash width
and die temperature.

45. Future Scope

46. 1. The process can be validated on actual experimental set up to check
the correctness of formulated model and to predict its real life
behaviour.
2. Other parameters or process variables like draft, fillet and corner radii,
coefficient of friction etc. can be taken into consideration for
optimisation purpose.
3. Die stress analysis and die wear analysis can be carried out to predict
and improve die life.
Future scope

47. [1]A Text book by S.N. Prasad, R. Sharan & N.P. Saksena, “Forging Die Design and
Practices”,1982, S. Chand & company ltd.
[2] A Thomas, “Forging Handbook Die Design” Drop Forging Research Association
Shepherd Street, Sheffield S3 7BA, 1995. “Fundamental of automotive Technology”
by Kirk VanGelder.
[3] G. Sritharan, Deign and Mass Optimization of Independent Multi Link
Suspension for Ride Performance GM India Pvt. Ltd., ITPB, Whitefield Road,
Bangalore.
[4] J. Mahishi, Nonlinear Static and Analysis of Automotive Control Arm, Ms & M
Engineering Inc, Farmington Hills, MI, USA.
[5] “ASM Metals Handbook” Forging and Forming, Vol. 14, 9th Edition, ASM
Handbook Committee, USA, 1993.
[6] Indian Standards IS: 3469 (Part I to III) – 1974
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50. Thank You