Rigid Body(PRBODY) in Optistruct

Subash Karthikeyan

Good Morning,

      I want to press a tyre axisymmetric model against a rigid body, usually i use abaqus profile where we have a card image for property as RIGID_BODY, which we can use for making analytical rigid surface. But i want to do it in Optistruct profile, because i will be using optistruct as a solver. I tried looking into help it shows it has PRBODY card image for property to make rigid body but when i'm creating model it is not showing the PRBODY option.

Is there any solution for this?

Note: I have attached a simple model for showing the problem.

Thomas Quenaon_21507

Hi Subash Karthikeyan,

You can use the RBODY card for this:

BR-

Thomas

Ingeniorator

Thomas Quenaon_21507 said:

Hi Subash Karthikeyan,

You can use the RBODY card for this:

BR-

Thomas

Quick question on this, is this rigid body option the recommended way to define them? Before, it apparently was usual to just create a surface mesh and constrain it with RBE2 elements or to define a PRBODY card image as mentioned above. Is there a description on how to use it correctly in Hypermesh? The rigid definition seems to have been altered several times in the past years, so going through older tutorials is getting confusing in regard to the right method.

I tested the method just to find that the rigid body contains some stresses as well. What's happening here?

Thomas Quenaon_21507

Ingeniorator said:

Quick question on this, is this rigid body option the recommended way to define them? Before, it apparently was usual to just create a surface mesh and constrain it with RBE2 elements or to define a PRBODY card image as mentioned above. Is there a description on how to use it correctly in Hypermesh? The rigid definition seems to have been altered several times in the past years, so going through older tutorials is getting confusing in regard to the right method.

I tested the method just to find that the rigid body contains some stresses as well. What's happening here?

Hi Ingeniorator,

The most elegant way is to use RBODY, you can also use a RBE2, it will give you same results. Regarding your question on stress, I'm not sure what you've done here ?

BR-

Thomas

Ingeniorator

Thomas Quenaon_21507 said:

Hi Ingeniorator,

The most elegant way is to use RBODY, you can also use a RBE2, it will give you same results. Regarding your question on stress, I'm not sure what you've done here ?

BR-

Thomas

Hi, sorry for the sparse information yesterday, I was in a hurry. I'm not sure myself what I've done there in terms of the rigid setup. It's two perpendicular cylinders being pressed against each other as shown below. I defined the rigid body intuitively because I did not find a tutorial for this specific utility. As you can see in the results above and below, the rigid body shows a small amount of stress as well as displacement, so I reckon that something's wrong with my rigid definition.

 

 

Thomas Quenaon_21507

Ingeniorator said:

Hi, sorry for the sparse information yesterday, I was in a hurry. I'm not sure myself what I've done there in terms of the rigid setup. It's two perpendicular cylinders being pressed against each other as shown below. I defined the rigid body intuitively because I did not find a tutorial for this specific utility. As you can see in the results above and below, the rigid body shows a small amount of stress as well as displacement, so I reckon that something's wrong with my rigid definition.

 

 

Hi,

Yes I'm gussing someting is wrong here. Isuggest you to have a look at the tutorial:

OS-T: 1560 3-Point Bending using RBODY

This will explain you in details what is a reference node and what elements to choose for the element set definition.

BR-

Thomas

Ingeniorator

Thomas Quenaon_21507 said:

Hi,

Yes I'm gussing someting is wrong here. Isuggest you to have a look at the tutorial:

OS-T: 1560 3-Point Bending using RBODY

This will explain you in details what is a reference node and what elements to choose for the element set definition.

BR-

Thomas

Thanks, that was the right one. Interestingly, the tutorial seems to contain a few differences compared to the corresponding example file, which made the former non-convergent.

Ingeniorator

Ingeniorator said:

Thanks, that was the right one. Interestingly, the tutorial seems to contain a few differences compared to the corresponding example file, which made the former non-convergent.

Interestingly, one of the rigid beams from the example file also shows a small amount of displacement. This behaviour is very odd.