selecting solid elements at a offset from top and bottom surface of model

Altair Forum User

Hi ,

 

I want to select elements, which are at a distance of 50mm from the top and bottom surface of the model.

 

My aim is to transfer solid elements from the design space into the non-design space. 

 

Since , I have solver deck so there is no geometry available to create the void.

 

Problem is : how to select elements which are at 50 mm and cover region having dimensions 22 X 20 m. The existing model is in metre.

 

Is there anyway to do the same in HyperMesh?

 

Looking forward to your response.

 

Thank you.

 

Altair Forum User

Hi,

 

could you please explain what do you mean by transfering from design to non- design?

 

If you want to organize elements in design space to non design space, you can use Organize elements option in HyperMesh (Shift+F11 is the shortcut)

Altair Forum User

Hi,

 

I have the aircraft model meshed with solid elements. Now , I want to create a void (cabin) in the model so that it doesn't be a part of optimization process.

 

I know I can use organize to do the same.

 

But, concern is - I am interested in organizing only the elements which are at a distance of  50mm from the top and bottom surface of the model .

 

Issue is how to just select only elements between this limit of 50 mm ?  (snapshot attached)

 

Because I want elements which will be in 50 mm range only to be part of optimization and the rest selected elements between top and bottom in non-design.

 

 

I have already tried the organize approach, it just selects all the elements in that region. Doesn't allow me to leave elements which are in 50mm range from top and bottom.

 

Is it possible to do this ? Or please suggest any other approach of doing the same. 

 

Looking forward to your response.

 

Thank you.

 

 

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Altair Forum User

Hi,

 

Is it possible to do this in HyperMesh ? Else, please suggest some other approach to do the same mentioned in the previous message ?

 

Really looking forward to a response.

 

Thank you.

Rahul Rajan_21763

Hi,

If you want this to be done as per the given dimension then CAD software would have much user friendly option to trim the part and later you can mesh based on different component.

Organize command would help you to select and deselect element of desired location with some approximation.

Regards

Rahul R

Altair Forum User

Altair Forum User said:

Hi ,

 

I want to select elements, which are at a distance of 50mm from the top and bottom surface of the model.

 

My aim is to transfer solid elements from the design space into the non-design space. 

 

Since , I have solver deck so there is no geometry available to create the void.

 

Problem is : how to select elements which are at 50 mm and cover region having dimensions 22 X 20 m. The existing model is in metre.

 

Is there anyway to do the same in HyperMesh?

 

Looking forward to your response.

 

Thank you.

 

You can always use a command '*createmark 'entity' 'mark no' 'by box' 'properties'' 

First you get min and max height of the edge nodes and then you can write a command with variables:

 

set max_H 500

set min_H 100

*createmark elements 1 'by box' xxx [expr $max_h - 50] xxx xxx [expr $min_h + 50] xxx 0 'inside' 1 0 0

 

Please have a look at hypermesh help for further expanation how to use the command.

 

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

x0 – lower bound x coordinate

y0 – lower bound y coordinate

z0 – lower bound z coordinate

x1 – upper bound x coordinate

y1 – upper bound y coordinate

z1 – upper bound z coordinate

syst – the ID of a local coordinate system to which the coordinate bounds are relative to.  If 0, the global axes are used.

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.

 

 

'by box' x0 y0 z0 x1 y1 z1 syst location contained all tol