FEAP User Forum

FEAP => Input File Issues => Topic started by: shenrilin on January 30, 2017, 08:41:30 AM

Title: Simulate multi-materials system
Post by: shenrilin on January 30, 2017, 08:41:30 AM

Hi, everyone,

    I want to model a particle reinforced materials with several phases. I don't know how to create an input file to simulates such a problem. I appreciate if anybody can give me such an example, and instruction if possible.

   Thanks,

Title: Re: Simulate multi-materials system
Post by: Yaakov on January 30, 2017, 08:57:48 AM

Hi,

I would ask:
in literature, how can the similar problems be solved in a cae program? e.g. using of the user-defined umat? 

Title: Re: Simulate multi-materials system
Post by: shenrilin on January 30, 2017, 12:17:13 PM

Take Abaqus as an example, you can define several element sets and material sets, and then assign material models to the corresponding element sets.

I'm not familiar how to realize this procedure in feap.

All the best,

Title: Re: Simulate multi-materials system
Post by: Yaakov on January 30, 2017, 12:37:26 PM

Hi,

last year, I had asked a question about this topic:

http://feap.berkeley.edu/forum/index.php?topic=1366.msg4823#msg4823

I hope, It can be helpful...

Title: Re: Simulate multi-materials system
Post by: Prof. S. Govindjee on January 30, 2017, 01:14:40 PM

If you just want overlays of material models you can use the material set numbers.  So if you have an element (with nodes 1,2,3,4),
the one shown below declares the material set to be material set 1.

ELEMent
1  0  1   1 2 3 4

now you can define two materials to lay right on top of each other with two material declarations

MATErial 1
  SOLId,,1
  ....material parameters for first material...

MATErial 2
  SOLId,,1
  ...material parameters for second material...

The 1 after the SOLID,, set the material set number.  By default it is set to the material number but you can explicitly set it to 1 in this case and achieve an overlay effect.

Title: Re: Simulate multi-materials system
Post by: shenrilin on January 30, 2017, 03:00:23 PM

Thank you. What I want is to define different materials for different meshes, not overlay effects.

For example, I have two elements, element 1 (nodes 1,2,3,4) with user element elem10.f, element 2 (node 2,5,6,3) with user element elem11.f.

In the Input file, I define as following:

MATErial,1
    USER 10
     parameters....

MATErial,2
    USER 11

COORdinates
  1,x1,y1,z1
  2,...
  3,...
  4,...
  5,...
  6,....
           !Blank Termination Record
ELEMents
  1,0,1,1,2,3,4

ELEMents
  2,0,2,2,4,5,3

Boundary conditions follow

End mesh

Would you please tell me what's going wrong with my input file?

Title: Re: Simulate multi-materials system
Post by: Prof. R.L. Taylor on January 30, 2017, 04:33:03 PM

You should carefully check the output file to see what was missed.

In the example you have coordinates directly after the node number.  There should be two commas,
I.e.

Nd,,x,y,z

this is required even if you do no generation for missing values.  But there may be some other issue we do not see from the example, so always look at the output file.  Also doing a plot of the mesh, boundary conditions can give visual check you got things in.  If you can't plot their mesh something did not read as you expected, so check the output file.