Creating Several Solids Under a Single Mesh

Hi Waren

I also struggled a long time with defining two or more different materials. Several threads indicate how to proceed in this case, but until recently I didnot succeed.

To start with, I had a look at the *.comm files of the assembly in the advanted examples:
www.caelinux.org/wiki/index.php/Doc:AdvancedExamples

Also in this thread very useful information is given:
caelinux.com/CMS/index.php?option=com_jo...&catid=4#msg1770

Also JMB has added very usefull input for me:
caelinux.com/CMS/index.php?option=com_jo...&catid=4#msg2201

And here are some remarks of Andy Foan and our Administrator:
caelinux.com/CMS/index.php?option=com_jo...&catid=4#msg1863

In case you are interested in still an other very simple example you can have a glance at my comm and hdf files:


So this is how I proceed:
- in GEOMETRY define a block and a plane to divide the block in to two separate parts.
- choose Operations --> Partition
- choose Half-space partition (second choice) with object the block and Plane. This yields two separate blocks.
- Now create two new volumes blocktop and blockbot:
* 'New Entity' --> Group --> Create and select 'volume'.
* name: blocktop
* main shape: partition_1
* select in viewer window top of block and 'add' and 'apply'.
Repeat this for bottom of block 'blockbot' and close the window.
Now mesh partition_1 and take over the two volumes in the mesh by 'Mesh' --> 'Create Group' and basicly repeat the above steps from GEOMETRY.

Then start Code-Aster.
For convenience I start with the 'Linear Elasticity Wizard' to easily generate a starting file for only one material. After saving this *.comm file replace the material definition and assignment to the volumes:

MA=DEFI_MATERIAU(ELAS=_F(E=20500,NU=0.28,),);
MATE=AFFE_MATERIAU(MAILLAGE=MAIL,AFFE=_F(TOUT='OUI',MATER=MA,),);

by:

steel=DEFI_MATERIAU(ELAS=_F(E=205000,NU=0.28,),);
rubber=DEFI_MATERIAU(ELAS=_F(E=21000,NU=0.40,),);

MATE=AFFE_MATERIAU(MAILLAGE=MAIL,AFFE=(
_F(GROUP_MA='blocktop',MATER=steel,),
_F(GROUP_MA='blockbot',MATER=rubber,),),);

Start the solution and have a look at the mess file in case anything goes wrong. Eg. writing Steel in stead of steel makes Aster throw an error to the user.

BTW: I just used fancy numbers for rubber.
BTW2: Still cannot load files at the moment, the file tag has disappeared right now.

kind regards - kees<br /><br />Post edited by: Kees Wouters, at: 2008/10/12 10:11