Select specific nodes

Alberto Casas

Hello guys,

I was wondering how to select a group of specific nodes in order to fixed them in all dof. In this case, my geometry is a circle with a diameter of 170 mm. I would like to fix all the nodes that are further than a circunference with diameter of 80 mm, I mean the red part in the next picture. Any idea??

I was thinking of using the quick edit tool and create another circunference with an offset. The problem I see is that I have to edit the geometry creating a new line and mesh again. Is there any way of doing that without having to mesh again??

Thank you in advance!!!

Michael Herve

Hello Alberto Casas,

 

I see 2 cases for proceeding here:

- either in interactive mode, switching the box selection mode from rectangular to circle. But that won't be precise

- or use the command window, and command *createmark nodes 1 "by cylinder" with the relevant arguments:

 

"by cylinder" x y z i j k r h location contained all tol

Place entities on mark_id if they are inside/outside/on the boundary of the cylinder.

• x - base center x coordinate
• y - base center y coordinate
• z - base center z coordinate
• i - x-normal, x-coordinate of a point on the cylinder axis
• j - y-normal, y-coordinate of a point on the cylinder axis
• k - z-normal, z-coordinate of a point on the cylinder axis
• r - radius
• h - height. A negative value indicates the direction is opposite to the normal vector.
• location - The location of the entities to find, relative to the shape. Valid values are inside, outside, boundary and acrossboundary.
• contained - A flag that indicates whether the entire entity should meet the location criteria (1) or just any part of the entity (0) to be selected.
• all - A flag that indicates whether all entities (1) or only displayed entities (0) are considered for selection.
• tol - The tolerance to use. In most cases, this should be set to 0.

This is currently supported for nodes, elements, connectors, components (FE and connectors only), loads, equations, loadcols, systems, systcols, vectors, vectorcols, blocks, groups, sets, contactsurfs, points, lines, surfaces, solids and parts (FE and geom).

especially in your case you can define r (radius) = 80mm and location=outside

 

Then you can use a second command

*marktousermark nodes 1

so that you can retrieve your node selection.

 

Does that help?

 

Best Regards,

Michael