Learning Forum

[huhminnyoung]

Even if the load and boundary conditions are the same in a workbench static structure, the stress results change slightly as the load step increases.
What is this about?

[Akshay Maniyar]

Hi,

Can you share more details about the model? It will help to understand the issue and help you effectively. 

Thanks,

Akshay Maniyar

[huhminnyoung]

The model is a pressure vessel receiving bolt pretension.
Bolt pretension was applied in step 1, and steps 2 to 4 were secured with locks.
Internal pressure was applied in step 3 and no conditions were changed in step 4.
However, the analysis results of steps 3 and 4 were slightly changed.
I wonder what the reason for this is.

[huhminnyoung]

The model is a pressure vessel receiving bolt pretension. Bolt pretension was applied in step 1, and steps 2 to 4 were secured with locks. Internal pressure was applied in step 3 and no conditions were changed in step 4. However, the analysis results of steps 3 and 4 were slightly changed. I wonder what the reason for this is.

[Akshay Maniyar]

Hi, 

Can you share some inline images of the model? Also, how much is the difference in the result?

Thanks,

Akshay Maniyar

[huhminnyoung]

I'm sorry. Uploading images is difficult due to security concerns.

[Akshay Maniyar]

Hi, 

How much is the difference in result? Check for contact tool results, if it solving for the penetration which is changing the results.

 

Thanks,

Akshay Maniyar

[huhminnyoung]

The difference is not significant, less than 0.1%. However, since all conditions are the same, I expected the exact same results to come out, but it is surprising that the results are different.

[Akshay Maniyar]

Hi,

It might be changing as for some contacts solver might be trying to reduce penetration allowed with more substeps. 

Thanks,

Akshay Maniyar

[huhminnyoung]

Could frictional contact be that kind of penetration?

Thanks for your reply.