3D Solid- Element coorindate system alignment.

[AadithOm]

Hi Members,

I am planning to analysis a complex 3D geometry with 3D anisotropic material property. As the geometry is complex, it is not possible to take care of node numbering such that desired Element coordinate system is achieved for all elements. So the default element coordinate system of the elements are aligned in an arbitrary way. I request help in followings;

1)Is there a way to align the ELEMENT coordinate system of a group of elements to a particular user defined COORD ID ?
2)With PSOLID cord, it is possible to assign the material coordinate system to a particular user defined COORD ID. Is there a way to visualize the all 3 (x,y,z) MATERIAL axes of a 3D solid elements in Patran ?

I am using Patran 2008 R2

Regards
Aadith

 

[nlgyro]

Quoting:

> 1)Is there a way to align the ELEMENT coordinate system of a group of elements to a particular user defined COORD ID ?

Under Utilities---> Properties----> Align solid elements

Press the "help" button in this menu for a more detailed explanation.

> 2)With PSOLID cord, it is possible to assign the material coordinate system to a particular user defined COORD ID.

Field 4 of the PSOLID card makes it possible to define the material direction w.r.t to a user defined co-ordinate system.
Once the above option is used, Patran automatically updates the 3D element properties to have the material orientation defined to a specific co-ordinate system.

> Is there a way to visualize the all 3 (x,y,z) MATERIAL axes of a 3D solid elements in Patran ?

Yes, the above option under utilities contains "Display Material Coord" which achieves this.

 

[AadithOm]

Dear nlgyro,

Thanks for reply.

I tried Under Utilities---> Properties----> Align solid elements. Option, It correctly DISPLAY (only)the Material coordinate system as I wanted by creating multiple new COORD. But after executing this feature it does not update the PSOLID CORDM field. So when I write out the bdf and read again, the material orientation is same as the initial arbitrary orientation, NOT the aligned one using Utilities---> Properties----> Align solid elements option. I am using Patran2008R2 on Win7 64 bit machine.

Do you aware of any limitation of this utility on Patran2008R2 on Win7 64 bit ?

Display Material Coord option works fine.

 

[nlgyro]

What were the initial properties for the solid elements?. By initial, I mean before running this utility.

 

[AadithOm]

The initial properties were dummy as below
$ Elements and Element Properties for region : psolid.1
PSOLID 1 1 0
I tried using Method 1 (Z normal to surface, X along the vector option). This utility changes the material direction as expected (only in display), though it creates the new COORDs and Props, the newly created (rather modified) PSOLID props still referring to initial COORD 0 instead of referring to newly created COORDS. This is the exact problem.

I have attached my test model here, its very simple model should take just few seconds to load into Patran,that I created to understand the functionally of this feature.
Thanks for your time.

 

[nlgyro]

your material specification for the 3D solid elements is isotropic. This utility needs a 3D otho/3D aniso material property with an assignment to a CID (any CID will do) as an initial property.

Then run the utility.

 

[AadithOm]

Thanks for your continued help. I tired initial model MAT9, still the result is same. Is it working at your machine ?

 

[nlgyro]

I don't think hardware or OS has anything to do with this. I've tried this on a sample test model on my side and it works. Are you sure that you've followed the steps correctly?

 

[nlgyro]

for what's worth, I've attached a patran neutral file of your model, with the psolid's referring to the new CID's done using the above mentioned utility.

 

[AadithOm]

I still can't get
Align Type = Coordinate system (at the top of the utility); get work.
However, i could get
Align Type = Element IKJ; Get work.

In some machine, Align Type = Element IKJ, no working at all. It throws an error.
In some machine Align Type = Coordinate system just changes the display, but the not the actual PSOLID card.

Thanks again.

 

[AadithOm]

After few further trial, i could
Align Type = Coordinate system (at the top of the utility); get work.

The trick is that, In the inital PSOLID card, CORDM should not refer the global coordinate system. It should refernce any a dummy user defined coordiante syste. Then it works.
All these days i was trying with CORDM refering COORD 0. So i was not working. When refecnce this a dummy COORD 100(Say), it worked.
Also i figured one more thing, the Inital material model Not necessary to be MAT9 and MAT8, it works even with MAT1.
Thanks a lot for the time and help nlygro.

 

[nlgyro]

Quoting:

> Also i figured one more thing, the Inital material model Not necessary to be MAT9 and MAT8, it works even with MAT1.

MAT8 only works for 2D models. And I do not understand why directional properties would be needed for an isotropic material (i.e. MAT1)....

but glad you got it working.

 

[AadithOm]

Some times aligning the element coordinate system isrequired for MAT1 also. Usefull for post processing. Especially MscExplorer whcih work on ASIS only.
Thanks.