Aligning SHELL element over a SOLID element

[hnng]

Hi all,

I am hoping that the problem I am facing right now should have a trivial solution. May be I am not hitting it the right way. To simplify the explanation of problem I have simplified the geometric description:

I build a cube whose one end is at (0,0,0) and diagonally opposite end is at (1,1,1). And has meshed it using solid95 element. Now I select the area at height 1 and mesh it with SHELL181 element with uniform thickness of 0.5. When I issue /ESHAPE,1 and EPLOT, I see that SHELL181 element occupies space from height 0.75 to 1.25. I intended to use define this element from height 1 to 1.5. Is there some option or trick for doing that.

Regards
Harry

 

[cbrn]

Hi,
I think it's only a matter of selecting only the proper nodes, something like:
ESEL,s,... (select only the underlying elements of interest)
NSLE,s,... (selects the nodes belonging to the selected elements)
NSEL,r,loc,z,1,1.5, (reselects nodes in the range 1 to 1.5 following z-axis of the active coord sys)
<mesh commands>.

Regards

 

[cbrn]

Ah, I forgot: if your SOLID95 elements have only midside nodes at the coordinates 1 and 1.5, and have corresponding corner nodes at 0.75 and 1.25, then there is nothing to do: you can not overlay a 2D mesh putting corner nodes over midside nodes. So you would have to remesh more carefully with the SOLID95 elements.

Regards

 

[meshparts]

Hello,

I think Harry would like to offset the shells mid plane relative to the shell nodes.

For some shell elements, this ca be done using the real constants (CTOP, CBOT). For other elements (shell181) this should work with the command SECOFFSET.

Regards
Alex

 

[hnng]

Hi Guys,

Thank you for your comments. I was having some hardware problem so could not try out your suggestions earlier.

I appreciate cbrn comments, Its good to confirm this. I checked compatibility between the the shell181 and solid95 element and it seems to work fine.

Actually I was looking to offset the nodes from mid plane to bottom plane. SECOFFSET command worked for me using the following lines of codes

ET,2,SHELL181
R,2,2
sectype,1,shell
SECDATA,2, 2, 0, 3
secoffset,bot
aatt,2,2,2,,1

asel,s,loc,y,1
amesh,all

/eshape,1
eplot

Thanks to Alex for his comments.

now the nodes have been offset to the bottom plane and doing a simple static load analysis shows that the shell and the solid element bends together.

Thanks and Regards
Harry