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Mapped meshes and spheres

346gnu
12-Amethyst

Mapped meshes and spheres

Hello,

A quarter cylinder is easy

But what about a quarter sphere with the top chopped off?

The model really is as simple as it looks.

I can't be looking at the meshing problem in the right way.

Any thoughts

Thanks

1 ACCEPTED SOLUTION

Accepted Solutions

OK,

example 2 (volume regions only, but sphere with the top chopped off).

regards

paul

View solution in original post

14 REPLIES 14

example (asm).

regards

paul

346gnu
12-Amethyst
(To:skunks)

Thanks Paul,

I thought along similar lines but with volume regions in a part rather than an assy of parts. I couldn't get it to work.

It is a reasonable amount of prep.

Consider the following. just spent 10mins including geometry creation and manual shell meshing in Independent and 5 mins to remember my log in and post.

(I'm not suggesting for a minute that the modern user would want to do this, I just thought that since my last foray into this the methods may have moved on)

Thanks

OK,

example 2 (volume regions only, but sphere with the top chopped off).

regards

paul

346gnu
12-Amethyst
(To:skunks)

Paul,

That's what I tried !!

I have absolutely no idea what I was doing wrong.

I have taken your model and refined in different ways with volume regions as I thought it mattered whether these overlapped or were individual. It seems I can't break your model.

I will go back and look at my model again.

Thanks for you help

346gnu
12-Amethyst
(To:skunks)

Paul,

OK, I broke my model straight away.

Have a look at the attached.

A  6deg wedge of sphere rather than a 90deg portion. (6deg because the minimum edge/face angle=5eg)

Only 1 angular subdivision.

Can you spot the deliberate mistake?

Thanks

346gnu
12-Amethyst
(To:346gnu)

Creo 3.0m110

346gnu
12-Amethyst
(To:346gnu)

I think I can repeat the issue.

IF the 2 central wedges are selected such that the

FIRST wedge - pick triangular surfaces

SECOND wedge - does not permit you to pick faces so you have to use datum points

It then refuses to mesh.

Changing the following makes no difference :

wedge angle

angular subdivisions

degenerate form (taking care to change both central wedges)

It is as if the software has got stuck.

Redefine the FIRST wedge by removing vertices and replacing them with datum points

It is still stuck.

But interestingly, the FIRST wedge has forgotten which degenerate it is; a default is not selected

Selecting a degenerate for the FIRST wedge (and making sure this is the same as the SCOND wedge) seems to 'unstick' the software.

Thoughts?

test in creo simulate 3.0 m110

6 deg

regards

paul

Charles,

test 2 as asm (creo simulate 3.0 m110)

regards

paul

yes,

creo simulate stand alone (mechanica)  ist fine,

until creo 2.

creo2_stand_alone.JPG

user lost

regards

paul

346gnu
12-Amethyst
(To:skunks)

Paul,

it's not a bad thing Independent is now history.

The 'revolve' of shell elements was easy just so long as the user made sure it was only element edges were along the axis of revolution.

Using the Creo functionality we have to approach it differently and are forced to have the cylindrical central volume region; which isn't a problem.

bfn

Charles

Charles,

wedges and tetras are compatible, not bricks.

tetra_and_wedge.JPG

regards

paul

You'll need to slice your volume up, but use the butterfly meshing scheme. The mesh below is all brick elements.

mesh.PNG

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