1. SHEET METAL PART QUALITY
IMPROVEMENT THROUGH DIE
OPTIMIZATION USING AUTOFORM
AIRIC
2015
1

2. OBJECTIVES:
2
 Improvement of simulation accuracy and standardizing of sheet
metal forming simulation
 Phase transition of die quality improvement from final design to
simulation and early CAD surface design
 Decreasing of part development time
 Decreasing of part total cost

3. Causes of project
3
 Need in improvement of AUTOFORM predictions and results
 Time and cost waste during manufacturing and sheet metal part
development
 Poor dimensional accuracy in past projects

4. 4
1. Past method of simulation in AIRIC
2. Important effective parameters
3. Numerical and simulation investigations
4. Experimental and real results
5. Results verifications
1. Optimization methodology
2. Optimization of die surface based on successful try-out
3. Optimization of die surface based on successful high production rate
First part
Second part

5. Current method of simulation in
AIRIC
5
 There is no difference in simulation setup considering type of
operation and die size

First part

6. Effective Parameters
6
Parameter G1 G2 G3 G4 G5
Error tolerance 0.1 0.1 0.1 0.05 0.05
Max side length 30 30 20 10 10
Global sharp & fillet edge 1 1 1 1 1
Global radius 3 3 3 3 3
Max radius D D D D D
Max element angle 20 20 20 20 20
Max radius penetration 0.16 0.16 0.16 0.16 0.16
Initial element size 2*R min 2*R min 2*R min 2*R min 2*R min
Initial number of element
Max refinement level 7 7 6 5 5
Max displacement 0.22 0.22 0.22 0.16 0.16
Refinement extension D D D 2.5 2.5
Tangential refinement ON ON ON ON ON
Boundary penetration 0.11 0.11 0.11 0.11 0.11
Stiffness value <10 30 50 100 >100
Transient softening D D D D D
Stagnation ratio D D D D D
Young reduction factor D D D D D
Young reduction rate D D D D D
Number of end time step s 6 4 4 4 4
End time step 0.2 0.4 0.4 0.4 0.4
Drawbead plastification ON ON ON ON ON
Binder wrap steps
Crack limit D D D D D
Tool opening ON ON ON ON ON
Tool penetration to post D D D D D
D: dependent

7. Criteria of parameters categorizing
7
 Type of operation
 Thickness of sheet metal
 Part complexity
HOLDER BRKT – G5
REINF-ANCHORAGE LWR– G3
WHEEL HOUSE-G3
Standard simulation is the current method of simulation
Modified simulation is simulation based on parameters and values were listed in page 6

8. REINF-ANCHORAGE LWR
8

9. Verification of simulation results
9

10. FEM correlation OF wheel
house10
Experimental data:
Standard setting( 3.848mm)
Fine Setting(3.475mm)
User defined setting(2.734 mm)
×

11. STROCKE AT ONCET OF FAILURE (SOF)
SOF: 53 mm
Mesh size:
4mm
SOF: 54.8 mm
Standard setting of Autoform
MAT: SAPH 440
Thickness:
2mm
Tonnage: 65 TN
SOF: 52 mm
Mesh size: 3mm
SOF:55.764 mm
Mesh size: 6mm
SIMPLE CUP DRAWING COMPARISON IN ONCET OF FAILURE
USING AUTOFORM AND ABAQUS PREDICTIONS
SOF: 40 mm
Mesh size : 3 mm
11

12. Load - displacement
12
0
10000
20000
30000
40000
50000
60000
70000
0 10 20 30 40 50 60 70 80 90
AUTOFORM-ROUGH.
AUTOFORM-FINE
ABAQUS-MESH3
AUTOFORM-MESH4
AUTOFORM-MESH3

13. COMPARISON OF THICKNESS DISTRIBUTION BETWEEN ABAQUS AND AUTOFORM
13

14. Sample done projects
14
1. Feasibility phase
2. Die surface design
3. Manufactured die

15. REINF RR HANGER BRKT, LH
DRAWBEAD
UNKNOWN
Drawbead design and
optimization
Effect of drawbead design on
failure prevention
15
Existence of failure on part
Feasibility phase

16. FR DOOR OTR RR VIEW MIRROR MTG PLATE UPR, LH
Existence of failure on part
Subjected fillet design
and optimization
Feasibility phase
16

17. C-PILLAR UPR
17
Die surface design

18. 18
Extreme failure all around drawn part
Die surface design

19. 19
Defect source
Absence of material flow
Lowest price solution
Drawbead design and optimization
Presence of flow and successful drawing
Die surface design

20. COMPARISON OF FLOW BEFORE AND AFTER OPTIMIZATION
20
Die surface design

21. 21
Die surface design
Improvement part quality
Three different area optimization
Reaching minimum springback amount o
0.75 mm

22. BUMPER
CENTER22
Die surface design

23. SPRING
BACK23
Die surface design

24. Problem on part: severe failure & wrinkle on part
Solution: drawbead optimization based on lowest cost in
order
To eliminate failure and minimized springback
WHEEL HOUSE,RR
24
Manufactured die

25. unknown
38%
B1
2%
B2
4%B3
9%
B4
7%B5
4%
B6
7%
B7
3%
B8
2%
B9
2%
B10
3%
D1
4%
D2
3%
D3
7%
D5
2%
D6
3%
D7
2%
formability objecftive function
0
1
2
3
4
5
6
7
8
9
10
B1 B2 B3 B4 B5 B6 B7 B8 B9 B10 D1 D2 D3 D4 D5 D6 D7
25
Manufactured die
Here there are parameters which affect formability of part
Above parameters are sections of drawbead

26. B-PILLAR-INR-EXTENSIONManufactured die

27. Manufactured die
Existence of severe failure on part

28. Manufactured die
Optimized areas Successful product

29. Distance blocks thickness
Cushion pin variable
Blank locators (Blank position deviation)
29
Optimization of die surface based on successful high production r

30. SPRING BACK DURING TRY-OUT
Cpk = 1
Cpk = 1.33
Cpk = 0.66
SPRING BACK DURING PRODUCTION
UNKNOWN
21%
X-B
72%
Y-B
5%
X-D
0%
Y-D
2%
30

31. 31
Thank you for your attention