Superficial Stresses on 3D Castings? Membrane elements?

Joel Rodarte

I asked this question before in the forum but I am open to hearing new suggestions.

 

In Ansys and Abaqus solvers I Used to apply a 'Skin' (2D elements based on the outer surface of 3D elements) on castings in order to read superficial stresses in Hyperview. These elements were membrane elements and were declared different than regular shell elements. (.01 thicknesss shell elements)
 

For Optistruct which type of element is the one suited as membrane element?

Is there any other approach to read superficial stress on castings?

 

Thank you!

Rahul Rajan_21763

If you are looking for surface stress then in V2017.2, surface stresses can be requested without having to model additional membrane elements.Please attached attached material for same.

Unable to find an attachment - read this blog

Dominic_21343

In the instructions provided here, it states as the 2nd step:

     In addition to that, STRESS(GAUSS) also needs to be defined in the I/O section

I also read in the Knowledge Base to set STRESS(GAUSS) = YES, so seems a similar instruction.

Please help guide me on how to do this?

Adriano Koga_20259

Dominic_21343 said:

In the instructions provided here, it states as the 2nd step:

     In addition to that, STRESS(GAUSS) also needs to be defined in the I/O section

I also read in the Knowledge Base to set STRESS(GAUSS) = YES, so seems a similar instruction.

Please help guide me on how to do this?

Hi @Dominic 

You can still use Membrane, defining a thin shell and turning on PARAM,SHL2MEM,0.01 >> all shells with thicknes les than 0.01 will act as membrane.

 

If you want to try the other option, directly on the solid, you will need 2 things:

- control card, GLOBAL_OUTPUT_REQUEST, ask for STRESS, and choose position as GAUSS

- add into your property PSOLID, the option ISOP=INT0

Dominic_21343

Adriano Koga_20259 said:

Hi @Dominic 

You can still use Membrane, defining a thin shell and turning on PARAM,SHL2MEM,0.01 >> all shells with thicknes les than 0.01 will act as membrane.

 

If you want to try the other option, directly on the solid, you will need 2 things:

- control card, GLOBAL_OUTPUT_REQUEST, ask for STRESS, and choose position as GAUSS

- add into your property PSOLID, the option ISOP=INT0

Hello Adriano,

Thanks for your quick feedback. I will try this control card method.

For the other method you mentioned about creating a membrane, sorry, I don't know how to do this. That was my original search in Altair's Knowledge Base, trying to create a membrane using the surface of the elements of a solid body. I saw some posts about this back in 2016, but the option seems no longer available under "Tools" in my 2019.1 HyperWorks. If you have any guidance or links to posts about this method, I appreciate you sharing it with me.

Thank you for your support.

Dominic