Week 4- Rolling operation

OBJECTIVE

To carry out a static structural analysis on a rolling operation that is being carried out on a workpiece made of copper. Before carrying out the analysis, the workpiece needs to be edited as per requirements and there needs to be a displacement of 90mm of the workpiece during the operation and analysis.

MODEL IMAGE

PROCEDURE

1. After opening ANSYS Workbench, we are met with the Project Schematic window. Here, we can select the 'System Structural' analysis system on the left. Doing so creates a new project. Here, we can rename the project and also change the material if needed. We will need to right-click 'Geometry' and select 'import'. The file provided for this project should be selected. 

Now, we can add the materials right here and make our job easier for later. To do that, we need to double-click Engineering Data'. This opens up the list of inserted materials. We can pick materials we need from the repository listed here. The material we need is Copper Alloy and that should be listed in the General Non-linear Material data source.

After that, we simply need to click the yellow '+' symbol on each material's corresponding 'add' column to add these specific materials to the project. Once we are done, we can simply close the tab.

We can then exit out of the engineering data tab and return to the project schematic window, where we can right-click model and select 'edit'. This will bring the model up in the SpaceClaim interface.

2. In the SpaceClaim interface, we are to increase the length of the workpiece by 60mm and decrease its size on both sides by 8mm. To do that, we can make use of the pull tool and specify the increment and decrement as shown:

2. After editing the model, we can simply close SpaceClaim and return to the project schematic window, where we can right-click geometry and select 'edit'. This will bring the model up in the Mechanical interface (we may need to right-click geometry and click 'update' before doing this).

3. In the mechanical interface, in the outline, under geometry, we can rename each of the components if needed. We can rename each of the rollers and the workpiece as shown. The workpiece is assigned the copper alloy material as well.

 

4. Moving on to the connections, go to the list of contacts and select both the contacts. Then right-click them and flip the contacts and targets. The rollers/wheels need to be the targets and the workpiece should be the contact in both cases.

After doing that, we can select both contacts and edit their attributes. The crucial ones are highlighted in the following screenshot:

5. After that, we can go ahead and create cylindrical type joints for both the rollers. To add joints, we can right-click the Contact entity, and then go to Insert > Joint. These joints will be body-ground types with the axis of rotation oriented in the opposite direction of the positive global z-axis.

6. We can then work on the mesh. We just need to work on mesh sizing. To do that: right-click Mesh in outline > insert > sizing. We need to assign the entire workpiece a mesh size of 4 mm. We can then right-click mesh and select 'generate'.

7. Next, we shall work on the analysis settings. The number of steps would be 14. Selecting all the steps, we need to assign the following settings:

8. Next, we need to right-click static structural > Insert > Joint Load. We are to add a joint load for each of the cylindrical joints we created earlier for the rollers. They will both be rotation types and the magnitude will be in tabular form. Also, one of the joints will have negative values since the direction of rotation will be the opposite of the other. The following is a screenshot of one of the joint loads:

We can then add a displacement attribute for the workpiece since it needs to be pushed between the rollers. To do so, we simply need to right-click static structural > insert > displacement. The geometry is going to be the entirety of the workpiece and the y component is to be defined via tabular data (since the movement will be along the y axis).

The values are increased in an almost linear progression. The challenge requires the displacement to be 90mm, so the increments have been decided accordingly. Furthermore, they are negative since the workpiece is moving in the opposite direction of the positive Y-axis.

9. Now we can generate the outputs. To do this, we can right-click Solution > Insert > Strain > Equivalent (Von-Mises) (for strain), right-click Solution > Insert > Stress > Equivalent (Von-Mises) (for stress), right-click Solution > Insert > Deformation > Directional (for directional deformation). Each of these outputs can be generated for particular bodies, surfaces, etc. So barring the equivalent stress output, all other outputs are to be of specific regions.

Both the strain and directional deformation will be that of the workpiece. The directional deformation will be measured along the Z direction and that should be specified in the attribute settings. Finally, to prove the 90mm displacement, we also need to create a directional deformation output in the Y direction which will be that of any face on the workpiece, most likely the one that is at the tip of the workpiece.

Now, all we need to do is right-click solution again and click 'Evaluate all results'. Finally, when the analysis is done, we can view the results by simply clicking each of these solution entities we created, in the Outline menu.

OUTPUTS

Equivalent Stress for the whole setup

Maximum & Minimum Stress

Equivalent strain on the workpiece

Maximum and Minimum Strain

Directional deformation in Z direction

OBSERVATIONS

Understandably, the regions that are being worked on (points of contact between rollers and workpiece) by the rollers experience the most stresses. The tip of the workpiece experiences the least amount of stress due to its lack of involvement in this entire process. The stresses cause deformation and that results in strains which are, again, in regions where high stresses were generated due to the metal forming process.

In the case of Z directional deformation, understandably due to the Poisson effect, we can see maximum deformation on either side of the workpiece.

To prove the displacement was exactly 90mm, in addition to ensuring the displacement tabular values were entered accordingly, a directional deformation output in Y direction was also taken. As we can see, the displacement of the tip of the workpiece is exactly 90mm:

RESULT

Therefore, structural analysis was carried out on this rolling setup. The requested outputs of stress, strain and directional deformation were also generated and it was also proven that the workpiece was displaced by 90mm in the Y direction.