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Contributor
jjohnson
Posts: 21
Registered: ‎07-10-2008
Accepted Solution

Connecting plates to solids

682 Views, 6 Replies
08-21-2012 01:24 PM

How can I obtain the connection between this plate and solid parts.

 

add pictures

 

Thank you

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INACTIVE_AstroJohn
Posts: 492
Registered: ‎03-25-2010

Re: Connecting plates to solids

08-21-2012 02:44 PM in reply to: jjohnson

Hi JJ,

 

Your model is incorrect to be used as plate elements. What you actually have is "sheet metal" folded around a a channel, and then the channel was slipped out. So the brick element with the load is bonded to the "outside face" of the channel. By exaggerating the displacement, it looks as if the outside face of the bottom flange of the channel is passing through the inside face of the bottom flange of the channel.

 

Make sense? See my attached images and "Help > Simulation Mechanical > Mesh Models > Mesh Overview > Meshing CAD Solid Models > Model Mesh Settings".

 

You should create a model using solids and surfaces in Inventor where the surface parts are in contact with the solid parts, and the surface parts will become the plate elements in Sim Mechanical.

 

Sincerely,
John Holtz, P.E.
Senior User Experience Designer, Simulation
Autodesk, Inc.

Current version of Mechanical & Multiphysics: 2013 SP1 (2013.01.00.0012 28-Jun-2012)
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Contributor
jjohnson
Posts: 21
Registered: ‎07-10-2008

Re: Connecting plates to solids

08-23-2012 07:47 AM in reply to: jjohnson

Thanks John

 

 

I have created a new model using surfaces in inventor where the surfaces parts are in contact with the solid part.

 

When I open the new model in Sim mechanical, I can not to see the surface parts, only I can to see the solid part.

 

Is not possible import to Sim Mechanical mixed parts (surfaces and solids) from inventor?

 

Add picture

 

Thanks

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Employee
INACTIVE_AstroJohn
Posts: 492
Registered: ‎03-25-2010

Re: Connecting plates to solids

08-23-2012 09:02 AM in reply to: jjohnson

Sorry, I did not pick up on the fact that you are using older software. (I think 2011 from the last image you attached.) The capability to import solids and surfaces in the same assembly was added to version 2013 (the current version).

 

I do not know if the step format supports solids and surfaces, but it is worth a try. Otherwise, you could

  1. In Simulation, save the current solid model to a new name.
  2. In Inventor, suppress the brick parts, leaving only the surface parts.
  3. Push the surface model to Simulation.
  4. In Simulation, use the "File > Merge" command and merge in the solid model. Because both models were created from the same assembly, everything should match up.
  5. Set the Model Mesh Settings to "Plate/Shell".
  6. Right-click on the solid parts and set the Part Mesh Settings to Solid.
  7. Mesh the model.

 

Sincerely,
John Holtz, P.E.
Senior User Experience Designer, Simulation
Autodesk, Inc.

Current version of Mechanical & Multiphysics: 2013 SP1 (2013.01.00.0012 28-Jun-2012)
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Contributor
jjohnson
Posts: 21
Registered: ‎07-10-2008

Re: Connecting plates to solids

08-26-2012 07:25 PM in reply to: INACTIVE_AstroJohn
Thanks John I have created a new model using surfaces in inventor where the surfaces parts are in contact with the solid part. When I open the new model in Sim mechanical, I can not to see the surface parts, only I can to see the solid part. Is not possible import to Sim Mechanical mixed parts (surfaces and solids) from inventor? Add picture Thanks ----------- La informaci?n adjunta es exclusiva para la persona a la cual se dirige este mensaje, la cual puede contener informaci?n confidencial y/o material privilegiado. Cualquier revisi?n, retransmisi?n, diseminaci?n o uso del mismo, as? como cualquier acci?n que se tome respecto a la informaci?n contenida, por personas o entidades diferentes al prop?sito original de la misma, es ilegal. Si usted recibe este mensaje por error, favor notif?queme y elimine este material. Gracias. ? ? ?
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Contributor
jjohnson
Posts: 21
Registered: ‎07-10-2008

Re: Connecting plates to solids

08-30-2012 07:25 AM in reply to: jjohnson

Thanks John

 

Unfortunately Assembly models using shells/plate to not import into algor 2011 properly.  In this moment We are not have Autodesk mechanical 2013.

 

By the above I can not to do this:

 

In Simulation, save the current solid model to a new name. In Inventor, suppress the brick parts, leaving only the surface parts. Push the surface model to Simulation. In Simulation, use the "File > Merge" command and merge in the solid model. Because both models were created from the same assembly, everything should match up. Set the Model Mesh Settings to "Plate/Shell". Right-click on the solid parts and set the Part Mesh Settings to Solid. Mesh the model.

 

I have done the following:

 

  1. I have created a new model in inventor (iam) using surfaces and solid.
  2. I have created a derive assembly model in inventor (ipt) using the option “maintain each solid as solid body
  3. In simulation Set the Model Mesh Settings to "Plate/Shell". Right-click on the solid parts and set the Part Mesh Settings to Solid
  4. Mesh the model.

Results: (add pictures in zip file)

Displacements 0,85 mm

Stress  209 MPa

 

I have made calculations by hand and the displacements are very similar 0,79 mm.  The stress is very different 70 MPa (model may have singularities)

 

I have a questions:

Is correct to make derive assembly in Inventor (surfaces and solid) and open them in simulation? I prefer to work with inventor instead of step files.

 

Can I interpret the height stress to be a singularities?

Thank you

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*Expert Elite*
AstroJohnPE
Posts: 573
Registered: ‎08-30-2012

Re: Connecting plates to solids

08-30-2012 12:35 PM in reply to: jjohnson

Hi,

 

Based on what I can see from the images, it looks like the model is correct. And I agree that the highest stress is most likely a singularity. You can check by adding a refinement point at those spots to create a really fine mesh. If the stress goes way up, it is a singularity.

 

What do other engineers do in this type of situation? Look at the stresses in the nodes around the singularity and average those? Or even if the stress is accurate, it indicates that there will be some very local yielding and don't worry about that?

 

John Holtz, PE
Mechanical Engineer
Pittsburgh, PA

Simulation Mechanical user since Dec 1997
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