CHEXA Element Revolve 1

[MegaStructures]

Hello:

Don't meant to overuse the help of those on this forum with multiple questions in one day. I am creating a really beautiful hex-meshed solid with Mesh-->Revolve, but I have noticed that I get very poor quality elements at the center of the axis of rotation. Is there any easy way to avoid this? I did try cutting a cylinder out of the center of the hemisphere, but I will have to tet mesh the cylinder and glue to the hex mesh, which seems messy. I viewed a video from BlasMolero, a very active member, here, that seems to have the same issue as my model, which makes me think this isn't a big concern.

1. Are the skewed elements at the center not a big deal
2. Is there an easy way to setup a transition between the TET10 bar and the revolved quads with FEMAP V12, or glued the best way to go?

Would love to hear everyone's thoughts on this.

QUAD4 Revolve

QUAD4 Revolve w/ TET10 "Center Rod"

 

[rb1957]

I suspect it won't affect your results much. one way is to apply a test load to the fttg and see if the stress "misbehave".

Under simple tension all elements should be replying with the same principal stress (von mises if you prefer) depending on cross section area, except where there's an obvious stress concentration.

another day in paradise, or is paradise one day closer ?

 

[BlasMolero]

Hello!,
The video you mention is very old, now I won't run this way: I will avoid WEDGE elements at all, see this recent video:

https://www.youtube.com/watch?v=J6TTtN-lSog&t=26s

You can COMBINE the use of MESH > SWEEP command in both axial and rotational direction, this way you can avoid the creation of WEDGE and TET elemnts.
Best regards,
Blas.

~~~~~~~~~~~~~~~~~~~~~~
Blas Molero Hidalgo
Ingeniero Industrial
Director

IBERISA
48004 BILBAO (SPAIN)
WEB:

http://www.iberisa.com

Blog de FEMAP & NX Nastran:

http://iberisa.wordpress.com/

 

[karachun]

Why not cut cylinder out of sphere and then hex mesh it instead of tetmesh?
Note, FEMAP have own forum part, you can post FEMAP-specific questions here.

https://www.eng-tips.com/threadminder.cfm?pid=1234

 

[MegaStructures]

FEMAP wasn’t able to hex mesh my geometry, I assumed it couldn’t handle the hemisphere shape, but it looks like yours turned out quite well. I will subdivide the geometry in a different way and try again.

I thought about posting in the FEMAP forum, but thought this was more of a general FEA question, since I was asking about the impact of poor quality elements on my model, which isn’t exclusive to FEMAP.

 

[MegaStructures]

Excellent advice karachun. Looks like I have a really high quality mesh now.