Strand7 - adding a torque or moment

[bigbal]

Hi there Im new here and was so frustrated by this problem i thought i would join this community.

Basically I am trying to model torque on a shaft using brick elements with linear static analysis. Very simple in any FEA package but Strand it seems. I am fixing one end of the shaft, and applying a moment to the other end's nodes. The moment arrows display as they should, but the solver fails when run.

Can anyone help?

 

[jhardy1]

Brick elements in Strand7 (like many FEA programs) do not support rotational degrees of freedom at the nodes, so you have to model the torque using a statically equivalent set of forces, not nodal moments.

http://julianh72.blogspot.com

 

[ESPcomposites]

It does not make sense to add a moment to the node of a brick element (as jhardy said). What other FEA package are you referring to?

One common approach is to the connect a "wagon wheel" set of beams to the nodes of the solid elements. You can then apply a moment to the center of the wagon wheel. This will translate into a set of equivalent forces to the solid elements.

Brian

http://www.espcomposites.com

 

[IDS]

An alternative to applying equivalent nodal loads is to create a node on the centre line of the shaft and connect it to edge points with rigid links. You can then apply a moment to the new node.

Doug Jenkins
Interactive Design Services

http://newtonexcelbach.wordpress.com/

 

[IDS]

Sorry - I should have read ESPcomposites post before repeating what he had just said.

Doug Jenkins
Interactive Design Services

http://newtonexcelbach.wordpress.com/

 

[bigbal]

I was referring to Solidworks simulation. It seems easy in that package to apply a torque to models of tet. elements.

Thanks all for the suggestions.