Learning Forum

[hassam]

Hello

I have performed analysis on a composite cylinder with interference fit. I have few confusions in the results. First of all since its an axisymmetric model. i have applied constraints (displacement y=0) only on the bottom of the model. but results shows that the stresses are not evenly distributed from top to bottom. Should i apply constraints y=0 on the top as well.

 

 

Second I need to check if the stresses produced due to high internal pressure stays under the yield stresses of the material. the normal stresses are a lot different than the equivalent stresses. Which stresses should i consider in my analysis. Is there a module on ansys which can check the structural integrity of the model automatically

 

The model has been attached for you to see in detail.

[Sandeep Medikonda]

In an axisymmetric model, the symmetry is around an axis so wouldn't there be in-plane behavior? Also, If you are only constraining the bottom it is expected to observe the most resistance at the bottom which would ease up as you are moving towards the top. I see this behavior in the model. So, if the expectation is to observe symmetric behavior, yes, I believe you would have to fix the top.

Normal and Von-mises stresses are different quantities and are expected to produce different values. Refer to the help on their formulations

Von-mises stresses are often used to compare the numerical data with the test data. 

 

[hassam]

Thank you for your response Sandip. Exactly i want to compare the numerical data with test data. so stresses I have achieved using Lames equations

 

[Sandeep Medikonda]

Looks like you are trying to calculate the hoop and circumferential stresses. which is nothing but the normal stresses.

See if you can insert a cylindrical coordinate system and use it in the results under normal stresses.

I can't remember if it would allow it. If it doesn't you might have to calculate it using command snippets. See this article, however, this uses a legacy pipe element and not an axisymmetric one.