Change Material Type

[HVSmith]

Simple question that I can't seem to find the answer to anywhere (or work out... )

If I have an area, which I mesh, then generate the same area but moved back in the z-direction from the working plane, is there a simple way to make the generated area have different material properties to the original? (The element type should remain the same).

To me it sounds simple, but correctly implementing a solution has proved tricky.

Thanks for any advice.
HVSmith

PS, here's a snippet of the code if it helps:

ET,1,131	
KEYOPT,1,3,2					
KEYOPT,1,4,1				

MP,DENS,1,2000			

R,1							
SECTYPE,1,SHELL
SECDATA,1E-6,1						

L=0.011							
BLC4,-L/2,-L/2,L,L  					

ASEL,S,AREA,,1

AESIZE,ALL,L/20
AMESH,1,1,1

ASEL,S,AREA,,1						
AGEN,2,ALL,,,0,0,GAP,,0,0

 

[Drej]

Isn't this simply:

ET,1,131    
KEYOPT,1,3,2                    
KEYOPT,1,4,1                

MP,DENS,1,2000   ! Mat 1
MP,DENS,2,3000   ! Mat 2        

R,1                            
SECTYPE,1,SHELL
SECDATA,1E-6,1                        

L=0.011                            
BLC4,-L/2,-L/2,L,L                      

ASEL,S,AREA,,1

AESIZE,ALL,L/20
AMESH,1,1,1

ASEL,S,AREA,,1                        
AGEN,2,ALL,,,0,0,GAP,,0,0  

! ======================================
! Change to Mat 2, retain Type/Secn 1
MAT,2   
TYPE,1
SECNUM,1

ASEL,S,AREA,,2

AESIZE,ALL,L/20
AMESH,2,2,2

------------
See faq569-1083 for details on how to make best use of Eng-Tips.com

 

[HVSmith]

Ah, OK, yes, I see what you did, it makes sense, thanks!

Although I notice a flaw in my own logic... what I actually need to do is alter the SECDATA command for the newly generated area. So this isn't quite as simple as changing the material. Since the material is still the same, but it's the shell thickness that I wish to alter.

With you method above you are still referring to SECNUM,1.

So if I want this new area to have a different shell thickness is it suitable to create a new set of real constants?

R,2
SECTYPE,2,SHELL
SECDATA,2E-6,2

And then refer to SECNUM,2?
Because I still wish the area to be a SHELL131.

Or would you advise creating an entirely new ET,2 (which would be identical to ET,1 besides the SECDATA for shell thickness)?

I have tried both methods, unsuccessfully.

Thanks again for any further information or advice,
HVSmith

 

[Drej]

Personally, I always keep the types, mats and secs together for tidyness. Hence you need to create two seperate materials, types and secs. The real constant is irrelevant in the latest release of ANSYS since real constants for shells are no longer supported - this is done through SECDATA.

Once you've created the second set of type/mat/sec, then just simply change to these in the deck:

SECNUM,2
MAT,2
TYPE,2

and then mesh the area:

ASEL,S,AREA,,2
AMESH,ALL

This will work. If it doesn't there's something amiss.

Cheers.


------------
See faq569-1083 for details on how to make best use of Eng-Tips.com

 

[HVSmith]

Thanks Drej - very useful advice.
After messing around with the order in which I create, mesh and generate new areas I think I have this working correctly now.

Thanks again.
HVSmith