Week 3 Sheet metal Bending challenge

Case 1

AIM :

To perform sheet metal bending for 3 different materials ( Aluminium alloy 1199 , Copper alloy NL and Magnesium alloy NL ) and compare the equivalent elastic stress , elastic strain and total deformation in Y direction.

PROCEDURE :

1. Geometry :

• The model was imported on space claim .
• The individual parts of the setup were renamed accordingly.

2. Model Setup :

2.1 Material Properties :

• Aluminium alloy 1199

• Copper alloy NL

• Magnesium Alloy

2.2 Connections :

• Frictional connection of 0.1 was defined between punch to plate.
• Frictional connection of 0.1 was defined between punch to die.

2.3 Mesh :

• Punch was defined with element size of 4 mm.
• Die was defined with element size of 4 mm.
• Plate was defined with element size of 1 mm.
• Face sizing of 1 mm was defined on faces in contact (10 faces) , tetrahedron mesh.

2.4 Analysis Settings :

• Normal Stiffness factor = 0.1
• Method is changed to Augmented Lagrange .
• Interface treatment : offset , ramped effect.

2.5 Boundary Conditions :

• Displacement of 13 mm was input on the punch in the downward direction (-Y direction ).
• 0 mm of displacement was provided on the sheet in Z direction to provide constraint to the sheet.
• Displacement of 3 mm was input on Die after the punch retracts.

RESULTS :

1. Total Deformation (in Y direction)

a) For Al alloy 1199

b) For Copper alloy

c) For Magnesium alloy

Deformation (mm)	Al alloy 1199	Copper alloy	Magnesium alloy
Maximum	2.439	2.62	2.97

2. Equivalent Stress

a) For Al alloy 1199

b) For Copper alloy

c) For Magnesium Alloy

Equivalent stress (M Pa)	Al alloy 1199	Copper alloy	Magnesium alloy
Max Stress	58.373	119.18	80.18

3. Equivalent strain

a) For Al alloy 1199

b) For Copper alloy

c) For Magnesium alloy

Equivalent Strain (mm/mm))	Al alloy 1199	Copper alloy	Magnesium alloy
Max strain	0.00155	0.00176	0.00289

CONCLUSION :

The max equivalent stress and the maximum equivalent strain is the lowest for Aluminium alloy case , hence this material shows better resistive property in the case of sheet metal bending , whereas Cu alloy and Mg Alloy shows the most equivalent stress and strain for the applied consitions hence it has the least resistance during the bending test.

CASE 2:

AIM :

To perform sheet metal bending for Aluminium alloy 1199 with 2 different values of coefficient of friction.

PROCEDURE :

1. Geometry :

• The model was imported on space claim .
• The individual parts of the setup were renamed accordingly.

2. Model Setup :

2.1 Material Properties :

• Aluminium alloy 1199

2.2 Connections :

• Frictional connection of 0.1 was defined for case 1 and 0.19 for case 2 between punch to plate.
• Frictional connection of 0.1 was defined for case 1 and 0.19 for case 2 between punch to die.

2.3 Mesh :

• Punch was defined with element size of 4 mm.
• Die was defined with element size of 4 mm.
• Plate was defined with element size of 1 mm.
• Face sizing of 1 mm was defined on faces in contact (10 faces) , tetrahedron mesh.

2.4 Analysis Settings :

• Normal Stiffness factor = 0.1
• Method is changed to Augmented Lagrange .
• Interface treatment : offset , ramped effect.

2.5 Boundary Conditions :

• Displacement of 13 mm was input on the punch in the downward direction (-Y direction ).
• 0 mm of displacement was provided on the sheet in Z direction to provide constraint to the sheet.
• Displacement of 3 mm was input on Die after the punch retracts.

RESULTS :

1. Total Deformation (in Y direction)

Case 1 :

Case 2:

2. Equivalent stress :

Case 1 :

Case 2:

3. Equivalent Strain :

Case 1:

Case 2:

RESULT :

Results of the two comparison are tabulated below :

Case	Directional Deformation (mm)	Equivalent Stress (MPa)	Equivalent Strain (mm/mm)
Case 1	2.439	58.37	0.00154
Case 2	2.302	58.75	0.00155

CONCLUSION:

The directional deformation , equivalent stress and strain are higher in the case with greater value of friction coefficient .

CASE 3

AIM :

To perform sheet metal bending for Aluminium alloy 1199 with 2 different meshes (grid dependency test)

PROCEDURE :

1. Geometry :

• The model was imported on space claim .
• The individual parts of the setup were renamed accordingly.

2. Model Setup :

2.1 Material Properties :

• Aluminium alloy 1199

2.2 Connections :

• Frictional connection of 0.19 was defined between punch to plate.
• Frictional connection of 0.19 was defined between punch to die.

2.3 Mesh :

Case 1

• Punch was defined with element size of 4 mm.
• Die was defined with element size of 4 mm.
• Plate was defined with element size of 1 mm.
• Face sizing of 1 mm was defined on faces in contact (10 faces) , tetrahedron mesh.

No of Nodes = 12648

No of Elements = 4943

Case 2

• Punch was defined with element size of 2 mm.
• Die was defined with element size of 2 mm.
• Plate was defined with element size of 1 mm.
• Face sizing of 1 mm was defined on faces in contact (10 faces) , tetrahedron mesh.

No of Nodes = 40994

No of elements = 11165

2.4 Analysis Settings :

• Normal Stiffness factor = 0.1
• Method is changed to Augmented Lagrange .
• Interface treatment : offset , ramped effect.

2.5 Boundary Conditions :

• Displacement of 13 mm was input on the punch in the downward direction (-Y direction ).
• 0 mm of displacement was provided on the sheet in Z direction to provide constraint to the sheet.
• Displacement of 3 mm was input on Die after the punch retracts.

RESULTS :

1. Total Deformation (in Y direction)

Case 1 :

Case 2 :

2. Equivalent Stress :

Case 1 :

Case 2 :

3. Equivalent Strain :

Case 1 :

Case 2 :

RESULT

Results of the two comparisions are tabulated below :

Case	Directional deformation (mm)	Equivalent Stress (MPa)	Equivalent Strain (mm/mm)
Case 1	2.3021	58.748	0.00155
Case 2	2.3405	58.951	0.00155

CONCLUSION :

The results of Case 2 are comparetively greater than that of Case 1 due to finer meshing of Case 2 , the results are relatively sharper . Increasing the mesh size furthur more will not lead to a change in the results obtained .