Static Structural analysis of sheet metal bending process using ANSYS work Bench
Objective - Perform the sheet metal bending challenge for different materials
Case 1 - Use Aluminium Alloy 1199 for the First case Copper Alloy NL and Magnesium Alloy NL for second and third case.
Case 4 = With the material as Aluminium Alloy, change the friction coefficient to 0.19 and run the analysis as mentioned in Case 1. Compare the results with that in case 1.
Case 5 = Refine the mesh on the plate such that it doesn\'t cross the academic limit. With Aluminium alloy as material, run the analysis as in Case 1 and compare the results.
Solution - To set up the solution we first open the work bench.
Add all the materials to from engineering Library.
Material Properties
Aluminium Alloy 1199
Copper Alloy NL
Magnesium Alloy NL
Set Up -
Import the Geometry and open it in space clam to see if there are any irregularity in the model.
Now up date the imported geometry in the mechanical module.
In the Project tree we see geometry if we expand it we see different names given to different parts.
For our convenience we rename Dia, Sheet and Punch.
Now if we expand connections select all the connection and right click we see the option of rename based on defination.
change the contact to frictional and give a frictional coefficient of 0.1
contacts
Formulation is set as Augmented Lagrange normal stiffness si set to a factor of 0.1.
Mesh
For mesh we give a element size of 2MM for the Sheet and Faces which come in contact. And for the die and Punch Solids we use 5 mm as element size.
In the analysis Setting we change large deflection from off To On. This operartion is performed in 10 steps. We set energy dissipation ratio to 0.1 stabilization as constand and in form of energy.
For the bending of sheet metal we give dispalcement of Punch as random values up to 13.5 and the lifting the punch up to a value of -8 in Y direction.
Fix the movement of SHeet in Z direction by inserting value of zero.
For the Die it displaces after the punch has completed the punching process.
After Setting up the problem we solve it. we get following results.
Aluminium Alloy 1199
Stress
Strain
Directional Deformation (Y Axis)
Copper Alloy Nl
Stress
Strain
Directional Deformation
Magnesium Alloy NL
Stress
Strain
Directional Deformation
Comparison Table 1
| Equivalent Stress | Eq elastic strain | Directional Deformation | |||||
| (max)Mpa | (max)mm/mm | (max)Y(axis)mm | |||||
| Materials | positive | negative | |||||
| Aluminium Alloy 1199 | 52.64 | 0.0012867 | 2.8615 | -11.898 | |||
| Copper Alloy NL | 199.1 | 0.0022827 | 2.3652 | -12.498 | |||
| Magnesium Alloy NL | 163.24 | 0.0044629 | 2.3436 | -11.528 | |||
CASE 4 = Cnahging the coefficient of Friction to 0.19 for Aluminium alloy 1199
Stress
Strain
Deformation Directional (Y axis)
Comparison Table 2
| Aluminium Alloy 1199 | Aluminium Alloy 1199 | ||
| frictional coefficient 0.1 | frictional coefficient 0.19 | ||
| Equivalent Stress | 52.64 | 55.497 | |
| (max)Mpa | |||
| Eq elastic strain | 0.0012867 | 0.0013124 | |
| (max)mm/mm | |||
| Directional Deformation | 2.8615 and -11.898 | 2.8269 and -11.91 | |
| (max)Y(axis)mm |
Case 5 = Refining the mesh of the sheet and comparing with Case 1.
For Refining the mesh we use 1.5 mm Mesh for the sheet
Stress
Strain
Directional Deformation (Y axis)
Comparison Table 3
| Aluminium Alloy 1199 | Aluminium Alloy 1199 | ||
| mesh element size 2mm | mesh element size 1.5mm | ||
| Equivalent Stress | 52.64 | 56.22 | |
| (max)Mpa | |||
| Eq elastic strain | 0.0012867 | 0.0014485 | |
| (max)mm/mm | |||
| Directional Deformation | 2.8615 and -11.898 | 2.5389 and -12.498 | |
| (max)Y(axis)mm |
Simulation of bending process Link
https://youtu.be/TsTPidVJ9e4
Conclusion -
From comparison table number 1 we can see that stress on the sheet is maximum in case of copper alloy and minimum in case of aluminium alloy 1199 and Elastic strain is maximum in case of magnesium alloy and minimum in case of Aluminium alloy 1199.
Since yield strenght of copper is 280 Mpa highest of all the materials the stress is maximum. As for the bending (plastic deformation) of the sheet the external force must exceed the yield strength of material and below the ultimate tensile strength.
Copper >> magnesium >> Aluminium 1199 ----------Equivalent stress
magnesium >> copper >> Aluminium 1199 ----------Equivalent strain
Aluminium 1199 >> copper >> magnesium ----------Directional Deformation
From Comparison Table 2 we can conclude that there is slight increase in stress and strain value. And directional Deformation is almost the same.
From Comparison Table 3 we can conclude that all three parameters increases when we refine the mesh element size.