Week 3 Sheet metal Bending challenge

OBJECTIVE:

• Set up the model for sheet metal bending with respective contact and loads defined
• Compare the results of different materials
• See the results for same material with different mesh size and different friction co-efficient

STEPS:

Import material:-

• First import the material from engineering data sources
• Import the all the required materials for the analysis
• Import Aluminium alloy and duplicate it and rename it as aluminium alloy 1199
• Change few mechanical properties like Youngs modulus=62000Mpa; Yield strength=140Mpa;Tangent Modulus=209.46

Import geometry:-

• Import the model to the software
• Open it in space claim and look for any damage in the model
• If there is no issue with the model , open it in mechanical module and start setting up for analysis

Mechanical Module:-

• Update and enter the mechanical module
• Initially delete all the default contact
• Rename all the geometry for convinince
• First case assign the material as aluminium alloy 1199 to sheet geometry

Generate contacts:-

• Contact>Insert>Manual contact region
• First establish connection between punch and sheet,
  Contact=Bottom faces of punch
  Target=Top face of sheet
• Establish contact between sheet and die
  Contact=Bottom face of sheet
  Target=Die face

Define contact:-

• For both the generated contacts , define the contact
  Type=Frictional
  Friction co-efficient=0.1
  Behaviour=Assymetric
  Formulation=Argumented lagarange
  Normal stiffnes factor=0.1
  Interface treatment=Add offset, ramped effects

Meshing:-

• Initially use sizing option for punch and die body with 4mm element size
• Do sizing for sheet with 2mm element size
• Perform sizing for Contact faces of punch and die with 1mm element size
• Before generating the mesh, Only for sheet use tetrahedron element
  

Analysis Setting:-

• Create 10 steps for the analysis, apply the below settings for all the step
• Number of steps=10
  Large deflection=on
  Energy disipation ratio=0.1
  Stabilization=Constant
  Sover type=Direct

Define Load:-

• Define the displacement load for punch by selecting the top faces
• The punch has to bend the sheet and has to retrived back
• Static structural>Insert>Displacement
  Type=Displacement
  Defined by=Components
  X=Y=Z=Tabular data
  
• Now define the Displcement load for sheet, the sheet should not move in global Z direction
• Select the side faces of sheet, insert displacement load
  Type=Displacement
  X=Y=Free
  Z=Tabular data(Where all the Z values should be zero , in order to loction the motion of sheet wrt Z direction)
• Define the displacement load for Die, The die should not move untill the bending happens
• Once the bending is done the, die should move in global negative z direction
• Select the bottom faces of Die to give the load
  Type=Displacement
  X=Y=Z=Tabular data
  

OUTPUT REQUEST:-

• Request the solution for von-mises Stress, Von-mises strain, Directional deformation with respect to Z direction , Von-mises stress for sheet
• Repeat All the steps and change only the sheet material for case 1
• For case 2, All the above steps remains same, change the friction co-efficient=0.19 for aluminimum alloy
• For case 3, Aluminium alloy as the material but the sheet mesh will be finer, i have used element size=0.75mm, so that the nodes did not cross academic limit

RESULTS:

Aluminium Alloy 1199:-

• Von-mises Stress
  
• Von-mises Strain
  
• Directional Deformation
  
• Von-mises Stress for sheet
  

Copper Alloy:-

• Von-mises stress
  
• Von-mises Strain
  
• Directional deformation
  
• Von-mises stress for sheet
  

Magnesium Alloy:-

• Von-mises stress
  
• Von-mises Strain
  
• Directional deformation
  
• Von-mises stress for sheet
  

CASE 2:
Aluminium Alloy(Friction=0.19):-

• Von-mises stress
  
• Von-mises Strain
  
• Directional deformation
  
• Von-mises stress for sheet
  

CASE 3:
Aluminium Alloy(Finer mesh):-

• Von-mises stress
  
• Von-mises Strain
  
• Directional deformation
  
• Von-mises stress for sheet
  

• Material	Von-mises stress(Mpa)	Von-mises Strain(mm/mm)	Directional Deformation(mm)	Von-mises Stress(Mpa)
  Aluminium Alloy 1199	2664.8	0.043145	0.75954	2664.8
  Copper Alloy	4770.7	0.043536	0.7553	4770.7
  Magnesium Alloy	1963.7	0.04380	0.75259	1963.7
  Aluminium Alloy(friction=0.19)	3041.3	0.042998	0.75804	3041.3
  Aluminum Alloy(mesh=0.75mm)	2706.4	0.043692	0.76628	2706.4

CONCLUSION:

• From the above results we can see the max von-mises stress of the model is equal to max von-mises stress of sheet, this tells us the maximum stress occurs in the sheet comparing whole model
• Copper alloy has the higher stress value among all the material, strain is almost equal to all the material
• Comparing Case 1 and 2, the stress is more in case 2, this shows that the friction co-efficient plays a major role. Higher the friction co-efficient higher the stress generated
• Comparing Case 1 and 3, the difference in the stress is 1.55% which is not much, but the differences between other factors are negligble