Analysing Sheet metal Bending process with three different materials

Objective

To perform Sheet metal bending for 3 different materials mentioned below.

Case 1: Aluminium Alloy 1199( mentioned in the course video),Copper Alloy NL and Magnesium Alloy NL.

Case 2: With the material as Aluminium Alloy, value of friction coefficient is 0.19.

Case 3: With Aluminium alloy as material, changing the mesh size.

Importing the CAD model

The CAD model is imported and viewed in spaceclaim and checked for any errors.

The model has a punch and die arrangement with sheet metal as workpiece.

Simulation setup

Material assignment

The punch and die are assigned with structural steel and the sheet metal is assigned with three different metals namely. Aluminium Alloy 1199,Copper Alloy NL and Magnesium Alloy NL.

Contact Definition

The contact between punch and sheet metal as well as the contact between sheet metal and die are defined as frictional contact with frictional coefficient of 0.1

For case (2) the frictional contact is increased to 0.19

Mesh generation

The sheet metal and the faces of punch and die which come in contact with sheet are alone meshed with an element size of 1mm.

Other parts are meshed with an element size of 4mm.

For case (3) - the sheet metal and the faces of punch and die which come in contact with sheet are alone meshed with an element size of 1.5 mm. The sheet metal elements are of tetrahedrons type

Analysis settings

Displacement of Punch

The top and side faecs of punch are selected and given a downward displacement in Y-axis in a tabular form

Displacement of sheet and die

The sheet metal is given zero displacement in Z-axis and X-axis direction. It is done to avoid any lateral movement.

The die is fixed and doesn't have any degree of freedom

Case (1) - Aluminium alloy 1199

Directional deformation (Y-axis)

Equivalent Strain

Equivalent Stress

Case (1) - Copper alloy NL

Directional deformation (Y-axis)

Equivalent Strain

Equivalent Stress

Case (1) - Magnesium alloy NL

Directional deformation (Y-axis)

Equivalent Strain

Equivalent Stress

Case (2) - Aluminium alloy 1199 with friction coefficient of 0.19

Directional deformation (Y-axis)

Equivalent Strain

Equivalent Stress

Comparing the results

Case (1) - Among the three materials used Aluminium alloy 1199 has the least amount of stress developed.

Case (2) - with Aluminium alloy 1199 as material, changing the friction coefficient from 0.1 to 0.19 doesn't affect the results.

Case (3) - with Aluminium alloy 1199 as material, increasing the mesh size from 1mm to 1.5mm doesn't affect the results.

The results can be further verified by performing a grid dependency test.

Ansys file link

https://drive.google.com/file/d/1AcHL5hf4TTpw9HfEGfWbD8UqFEYy68zL/view?usp=sharing