Tek-Tips is the largest IT community on the Internet today!

Members share and learn making Tek-Tips Forums the best source of peer-reviewed technical information on the Internet!

  • Congratulations cowski on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

Constraining Motion to a plane

Status
Not open for further replies.

osbornmj

Aerospace
Joined
Jun 23, 2005
Messages
4
Location
US
Does anyone know how to constrain the motion of a node to a single plane in local cordinates?? ~ Matt
 
Constrain the translation in the out-of-plane direction.
 
The NASTRAN constraint set acts on the DOFs in the output coordinate system (not the definition coordinate system). If you are aligned with the global coordinate system, you just constrain the out-of-plane translation. If you are not aligned, you will need to define a local coordinate system, reference this coordinate system as the output coordinate system on the GRID card(s), then constrain the out-of-plane translation.
 
To get the correct answer I had to create a reference node within the local cordinate system and connect it to my original node. I then set the spring constant really low for the plane I wanted motion in and really high for the planes I didn't. Just constraining the motion to a single plane didn't work probably because it messed with the moments. Thanks for the help though.
 
Status
Not open for further replies.

Part and Inventory Search

Sponsor

Back
Top