Simulation Mechanical Forums (Read-Only)
Welcome to Autodesk’s Simulation Mechanical Forums. Share your knowledge, ask questions, and explore popular Simulation Mechanical topics.
cancel
Showing results for 
Show  only  | Search instead for 
Did you mean: 

fixing a point in a specific direction

3 REPLIES 3
Reply
Message 1 of 4
steelix
312 Views, 3 Replies

fixing a point in a specific direction

hi,

 

In autodesk simulation mechanical, how do I fix a point in one direction. the poit will be fixed so that movement in the +ve y direction is prohibited while it is alllowed in the -ve direction

thanks

3 REPLIES 3
Message 2 of 4
zhuangs
in reply to: steelix

The line elements (contact element, coupling element) can help do this.

 

-Shoubing

Message 3 of 4
steelix
in reply to: zhuangs

these options are available only in nonlinear analysis. but from there I can choses linear eleastic model for natural frequency analysis. any how to be exact the model is about soil (elastic cube) the top layer can not move in the upper direction it can only compress so how can I achieve this exactly.  

Message 4 of 4
AstroJohnPE
in reply to: steelix

Hi steelix,

 

I understood your first post (how to prevent a node from moving in + direction but free in the - direction), but I did not understand your second post (something about natural frequency).

 

A natural frequency (modal) analysis cannot contain any type of nonlinearity. Restraining a node in one direction only would be a nonlinear effect. So you will not be able to perform a modal analysis with the node restrained as such.

 

The elements that Shoubing mentioned (coupling, contact, or general contact elements) have a similar element type in linear stress. In linear, the element type is "Gap". The element definition lets you define whether the gap element works in compression (similar to nonlinear's "contact element") or tension (similar to nonlinear's "coupling" element). If you literally have just one node (or a few), you can draw the lines from the node(s) out to a free area in space, define the lines to be gap/contact elements, and fully constrain the free end of the elements. If you have a "surface" to prevent one-way motion, you can draw another part that matches the surface and use surface contact between the parts.

 

Hope this helps.

Can't find what you're looking for? Ask the community or share your knowledge.

Post to forums  

Autodesk Design & Make Report