×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Contact US

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Symmetry Fixture on Assembly

Symmetry Fixture on Assembly

Symmetry Fixture on Assembly

(OP)
I am trying to do a structural load analysis on a Geodesic dome which is symmetrical and can be divided way down which could really help with the setup and run time of the model. I used an Extruded-Cut to narrow the assembly down to the pie piece I want to do the analysis on but when running the model it still includes then entire model and all the parts in the analysis. Is there any way to make the Symmetry Fixture work in an assembly?


 

RE: Symmetry Fixture on Assembly

What you probably need is cyclic symmetry and that is not supported in Cosmos/M or Simulation.

Cyclic symmetry constrains nodes on symmetry faces to move together.

If this dome is made of thin members, you could use beams, make one section and then rotate copy it around.

 

TOP
CSWP, BSSE
www.engtran.com  www.niswug.org
www.linkedin.com/in/engineeringtransport
Phenom IIx6 1100T = 8GB = FX1400 = XP64SP2 = SW2009SP3
"Node news is good news."

RE: Symmetry Fixture on Assembly

(OP)
Thanks for the response kellnerp, I'll give that a look.

RE: Symmetry Fixture on Assembly

Could you apply a microscopic chamfer on all of the edges of the surface the cyclic symmetry constraint is applied to?  When you apply cyclic symmetry, only select  the face and not the chamfers.  This should help prevent the nodes from closing in on themselves.

RE: Symmetry Fixture on Assembly

@moreinr
The problem with a geodesic dome is the symmetry faces|edges|vertices are not on planes. A dome of this nature is not amenable to modeling with solids so chamfers make little sense as a surface or beam element can't be geometrically chamfered.

The issue with this type of symmetry is to get the nodes on the symmetry faces to move together and this requires two things:
1. The nodes are defined in a cylindrical or spherical coordinate system based on the axis of rotation
2. The nodes on the symmetry faces that would join with the face on the opposite symmetry face must be forced to move together. This requires using the CPDOF command in Cosmos/M. There is no corresponding method in Simulation.

This is a long standing deficit in the SRAC/SolidWorks FEA products. ANSYS and other FEA products have had this capability for a long time.  

TOP
CSWP, BSSE
www.engtran.com  www.niswug.org
www.linkedin.com/in/engineeringtransport
Phenom IIx6 1100T = 8GB = FX1400 = XP64SP2 = SW2009SP3
"Node news is good news."

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members! Already a Member? Login



News


Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close