Week 3 Sheet metal Bending challenge

Objective:

Sheet metal bending is to be performed for 3 different cases mentioned below

Case 1:

Find out the Equivalent stress, Equivalent elastic strain, and Total Deformation in the Y direction and compare the results for the three materials - Aluminum Alloy 1199, Copper Alloy NL, and Magnesium Alloy NL.

Case 2:

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 3:

With Aluminum Alloy as material, Refine the mesh on the plate, run the analysis as in Case 1 and compare the results.

Materials Assigned / Used:

S No	Material	Youngs Modulus	Tensile Yield
01	Aluminum Alloy 1199	62000 Mpa	140 Mpa
02	Copper Alloy NL	110000 Mpa	280 Mpa
03	Magnesium Alloy NL	45000 Mpa	193 Mpa

Mesh Properties:

Mesh Type

1. Tetrahedron for Sheet metal
2. Hexahedron for Punch & Die

Mesh Size (for Case 1 & 2)

For Punch & Die - 4 mm, with face meshing of 1 mm on the surfaces that will contact the sheet metal.

For Sheet metal - 1 mm

Mesh Size for Case 3

For Punch & Die - 2 mm, with face meshing of 1 mm on the surfaces that will contact the sheet metal.

For Sheet metal - 1 mm

Boundary Conditions / Constraints:

Frictional Constraint Established between Punch to Job & Die to Job.

Frictional Coefficient - 0.19

Punch & Die - Movement in Z & X direction locked (front & back, Left to right)

Punch is allowed to travel 13.5 mm in -Y direction and then retracts

Die is allowed to retract 3 mm in -Y direction after the punch starts retracting

Job / Sheetmetal - Movement is Z direction is locked

Analysis Results & Conclusion:

	Material	Coefficient of Friction	Mesh	Yield Limit	Eq Stress	Eq Strain	T.Deformation	C.Pressure Punch
C1-M1	Aluminum Alloy	0.1	4 & 1 mm	140 Mpa	183.49 Mpa	0.297 %	13.521 mm	11.33 Mpa
C1-M2	Copper Alloy	0.1	4 & 1 mm	280 Mpa	381.69 Mpa	0.349 %	13.376 mm	25.48 Mpa
C1-M3	Magnesium Alloy	0.1	4 & 1 mm	193 Mpa	271.98 Mpa	0.607 %	13.351 mm	15.62 Mpa
C2-M1	Aluminum Alloy	0.19	4 & 1 mm	140 Mpa	179.75 Mpa	0.291 %	13.453 mm	13.11 Mpa
C3-M1	Aluminum Alloy	0.1	2 & 1 mm	140 Mpa	190.4 Mpa	0.307 %	13.774 mm	19.79 Mpa

Inference:

1. Equivalent streses of all parts are higher than the yield limit. So the job is going to have a permanent deformation.

2. Copper being a tougher material needs higher force on the punch to deform. Aluminum alloy being the easiest ones.

3. When co-efficient of friction increases, slightly higher forces are needed to deform the job. The stresses are slightly higher for the same reason but the deformation is slightly lower confirming the hesitation of the part to deform.

4. When we go for a finer mesh, we can see the stress, strain & deformation values being slightly higher due to the refinement. But the results from coarse mesh are good enough to extract the results.