Learning Forum

[Rashi]

Hi, 

I'm using a CAD geometry which is modeled in solidworks to study the effect of interference between three components. Below diagram shows the components in the CAD geometry.

Following are the diameters of the three components.

component 1,2,3 outer radius = 10.0 mm

contact offset is defined as 0.25 mm

So there is 0.25 mm interference between in the components. 

I have split the model along the axis of the assembly where I can use same amount of division in tangential direction also bodies are split where nodes in the contact surface should match perfectly. 

Here's where I faced the issue,

When I used contact tool to get the initial information between the contact of component 2,3 the penetration is 0.25mm.

But in the contact surface between 1,3 the penetration is higher than the offset defined (0.25mm). Also there is geometric penetration visible. Which there shouldn't be any, since component 1,2 has the same outer diameter both components should have same initial interference. 

Also what I noticed was  even though surface of the solid bodies has higher tessellation the edge of the solid bodies has lower tessellation which made the edges look jagged.  

And the mesh follows the jagged edges of the components. The jagged edges also do not match tangentially between the components. Like shown in the image below.

Due to this issue the node near the edges show penetration but nodes away from the edge matches between the contact surface. As shown below.

 

This has only happened between component 1,3.

So I tried increasing edge quality in solidworks so the deviation should be reduced. Then in design modeler the edges have higher tessellation but when it gets imported in mechanical again the edges look jagged.

I tried to find any other option available to increase the tessellation inside mechanical but I was unable to do so. I want to solve this issue without changing the file format so I can perform parametric study with solidworks in future. 

I also found out that for *.stp and *.igs file format there's a option in design modeler to change the tolerance file importing the CAD geomtry. 

Any help would be highly appreciated.

Thanks.

 

[sk_cheah]

Hi Rashiga,

It looks like your mesh does not match exactly. You could split up the body into quarters from the end view (like pies) and apply shared topology. That way, the first node from each part is coincident and you would be able to apply identical hard mesh sizing for each part to match. 

 

Kind regards,
Jason

[Rashi]

Hi Jason,

Thank you for your reply. I do have already have divided the bodies in end view and also have hard sizing. So I tried applying shared topology as you have mentioned. Unfortunately it did not solve the issue.

Best Regards,

Rashiga 

 

 

 

[sk_cheah]

Hi Rashiga,

Did you partition your shaft and parent material to look like this? Note the quarter of the hole sizing can now be defined well. 

With that, there would not be any node penetration between the parts as shown in the end view here: 

I have in my CAD line to line and applied a 0.5mm offset in the contacts to create interference. The stresses is as follows:

I've  attached the archived V19.2 file here in case you need further details of applying hard sizing for the lines. 

 

Kind regards,
Jason

[Rashi]

Dear Jason,

 

Thank you very much for taking the time to create this simulation. I also have done similar to have explained previously. May be there's something wrong with the file I've used. Thanks again.

 

Best Regards,

Rashiga