find id of the knots of a helmet

[scroll86]

Hello.

I am a mechanical engineer, and I am involved in aerodynamic design of turmoil, and for this I am a little bit unloaded (a little...:biggrin in the use of software for mechanical analysis like ansys.

In general, mechanical analyses take care of their colleagues in cold mechanics, but this time we will have to do everything in our group, both mechanical and aerodynamic side.

mechanical mesh has to interface with that aero, and for this, we need to know the connectivity of the surface mesh of a shovel.
I'll explain better. considering the surface mesh of the shovel made with triangular elements, how can I get the ids of the three knots that constitute the three vertices of an element? I have already written the macro that for each node provides me position and deformation, but regarding the connectivity of the nodes are at the high sea.

Does anyone have any advice or guidance on how I could do that?

Thank you very much to all.. .

 

[volaff]

esel,s,p,, (selections the element you are interested in)
nsle,s (selections the nodes of the element above)

nlist (log the list of nodes).

ps: I am going to memory with ansys apdl

 

[scroll86]

esel,s,p,, (selections the element you are interested in)
nsle,s (selections the nodes of the element above)

nlist (log the list of nodes).

ps: I am going to memory with ansys apdl

Thanks for your help there are almost...
now I can element by element to select the nodes that make it; what I still can't do is purify the selection of the constituent nodes the element from those inside the shovel; Once they select the element, this presents both knots on the palare surface, and knots inside the shovel, which I do not want.

what I would like to get would be a text file that contains something like

id1--id2--id3

ids of the three knots forming a triangle on the surface of the shovel for all elements.

are now 2 or 3 days working at this macro (which for experts may seem stupid) but still not usable

 

[volaff]

Thanks for your help there are almost...
now I can element by element to select the nodes that make it; what I still can't do is purify the selection of the constituent nodes the element from those inside the shovel; Once they select the element, this presents both knots on the palare surface, and knots inside the shovel, which I do not want.

what I would like to get would be a text file that contains something like

id1--id2--id3

ids of the three knots forming a triangle on the surface of the shovel for all elements.

are now 2 or 3 days working at this macro (which for experts may seem stupid) but still not usable

ah ah ah.
The nice thing is another.

do you not understand that id has the surface, the shovel, same type of element, different boh?

 

[scroll86]

ah ah ah.
The nice thing is another.

do you not understand that id has the surface, the shovel, same type of element, different boh?

I did not understand what you mean.

the shovel is meshata with tetra elements

I have done so for now:
-created a named selection with the surface of the shovel (the knots are selected automatically)
-extract coordinates and id nodals
- Selected the elements to which surface nodes are associated on the shovel and extracted id relectives
- element by selected element the nodes that compose it

I can't move on here anymore.

Now I have four knots. How do I know if and what are those lying on the surface of the shovel?
Of course at least 1 will be inside the shovel, and that I would like to eliminate it from the selection of knots.

 

[volaff]

I did not understand what you mean.

the shovel is meshata with tetra elements

I have done so for now:
-created a named selection with the surface of the shovel (the knots are selected automatically)
-extract coordinates and id nodals
- Selected the elements to which surface nodes are associated on the shovel and extracted id relectives
- element by selected element the nodes that compose it

I can't move on here anymore.

Now I have four knots. How do I know if and what are those lying on the surface of the shovel?
Of course at least 1 will be inside the shovel, and that I would like to eliminate it from the selection of knots.

I don't really understand now.
post a piece of code and see that you can pull out.

ps: I write at least next to the most important lines of notes that help to understand

I'm sorry for a moment, but you need only the knots lying on the surface of the blade because you don't stop at:

-created a named selection with the surface of the shovel (the knots are selected automatically)
-extract coordinates and id nodals

 

[scroll86]

I don't really understand now.
post a piece of code and see that you can pull out.

ps: I write at least next to the most important lines of notes that help to understand
I'm sorry for a moment but you need only the knots that lie on the surface of the blade because you don't stop :

-created a named selection with the surface of the shovel (the knots are selected automatically)
-extract coordinates and id nodals

because mechanical mesh has to interface with fluid dynamic mesh, for an aeroelastic analysis. cfd code is not commercial and for the passage of a way of vibrating from mesh csd to mesh cfd we need both ids of the nod coordinates, and know which are the 3 knots that constitute a triangle on the shovel surface.

!this is a macro

resume

cmsel,s,blade
*get,numnode,node,count
*get,nummax,node,,num,max

*dim,nodeid,array,numnode
*dim,ncoord,array,numnode,3

*vget,nodeid(1),node,nlist
*vget,ncoord(1,1),node,,loc,x
*vget,ncoord(1,2),node,,loc,y
*vget,ncoord(1,3),node,,loc,z


*cfopen,'node','txt',/home/lpl/mesh_export/,
*vwrite,numnode
%10d
*vwrite,nodeid(1),ncoord(1,1),ncoord(1,2),ncoord(1,3)
%15.5f %15.5f %15.5f %15.5f
*cfclos

sln,r,0,all
*get,numele,elem,,count
*dim,elemid,array,numele
*vget,elemid(1),elem,,elist

*cfopen,'elem,'txt',/home/flpl/mesh_export/,
*vwrite,elemid(1)
%d
*cfclos

for now this is what I wrote.

then to go ahead my idea was to proceed so, once I know the ids of the elements, select through a cycle do each element through its id, and then select the nodes that make up it through the nsle command.
to try I selected an element I knew a priori that had three knots on the face of the mesh (I selected it by hand from the workbench) and I wrote these lines.

esel,s,elem,,58466
nsle,s

*dim,nodearray,array,4
*vget,nodearray,node,,nlist

*cfopen,'nodearr','txt',/home/lpl/mesh_export/,
*vwrite,nodearray(1)
%d
*cfclos

what I get is a text file made so
306
3111
3191
302

of these 4 ids the first three are those that constitute the triangle on the surface of the shovel, the 30236 instead lies in.
what I would like to get is a file done so
306
3111
3191

Obviously having questioned the hand element I already know regardless of what are the knots that interest me and what the foreign one; What remains to do is find the way to uncheck the inner knot.

then obviously should be the program that selects the knots on the surface and rejects the internal one, it is unthinkable to do it manually

this is what I thought of doing; There are probably a thousand better ways than this to do so, so if you think I have to go to another way not have remorse in telling me.

p.s.
You were very kind!

 

[volaff]

I would give the inner surface a certain id and then remove from the 4 knots those with id of the inner surface

 

[scroll86]

I would give the inner surface a certain id and then remove from the 4 knots those with id of the inner surface

erm... as you will understand I'm a bit of ansys hoe, it's the first time I use it, the few times I've had to deal with csd solutors I've always used more, but now I have to use ansys by force.

Your idea is certainly good, but I have no idea how to put it into practice.. .

 

[volaff]

you could give all internal surfaces a certain type identifier with material 1 for example and then uncheck from the nodes those that have material 1: I don't know if I was clear.

 

[scroll86]

you could give all internal surfaces a certain type identifier with material 1 for example and then uncheck from the nodes those that have material 1: I don't know if I was clear.

Yes and no, but it is easier than I know where to put my hands;
Unfortunately now I don't have the program or the pc underhand; concretely to select an internal surface how should I do?

then for the discourse of assignment of the materials they graft them in the most total darkness. . .

I'm sorry if I drive you crazy so much... :

 

[volaff]

In summary the shovel is not made of anything

 

[volaff]

you have to be able to give an identification to the elements of the internal shovel and one different to the external ones and then proceed with the selection and deselection depending on what you need.