Structure with Different Modulus when in Tension vs. Compression 1

[Gillchevny]

Hi,
I have a model of a structure which should have a Young's Modulus that is different when in tension than in compression. In essence, I have to assign 2 modulus values to the same model elements, and which modulus used depends on whether the model is experiencing compression or tension. Could anyone offer any suggestions as to how one commonly approaches this situation?
Thanks,
Gill

 

[RajuChander]

Hi Gill

I think you will have to run as to separate models, one for tension and other for compression. If it is a dynamic model then this will not be OK.

Raju

 

[mgage]

Hi Gill,

If you go to

http://www.ansys.net

or the xansys group on yahoo you can download the macro bilinear.mac. This macro runs your problem once, determines which elements are in compression/tension, then reruns the problem assigning the appropriate modulus. Hope this helps.

Marcus

 

[Gillchevny]

THANKS! I'll give it a shot.

 

[Vogtlaender]

Hi,
there are a couple of methods for applying properties in various loadcases
however, firstly u need to know which material you got, i.e. isotropic, anisotrop, orthogonal etc.
i give u the input for an anisotropic case i used recently:
MP,EX,1,550 ! Young's-Modul MP,EY,1,10000
MP,EZ,1,550
MP,NUXY,1,0.42 ! Poisson ratio
MP,NUYZ,1,0.016
MP,NUXZ,1,0.016
MP,GXY,1,600 ! Modulus of rupture
MP,GXZ,1,600
MP,GYZ,1,600


TB,ANISO,1 ! nonlinear material bahaviour, anisotropic
TBDATA,1,90 ! yield stress(tension(x,y,z))
TBDATA,2,90
TBDATA,3,30
TBDATA,4,5.5 ! new Young's-Moduli (tension)
TBDATA,5,100
TBDATA,6,5.5
TBDATA,7,90 ! yield stress(compression)
TBDATA,8,30
TBDATA,9,90
TBDATA,10,5.5 ! new Youngsmoduli (compression)
TBDATA,11,0
TBDATA,12,5.5
TBDATA,13,7 ! yield stress (Shear)
TBDATA,14,7
TBDATA,15,7
TBDATA,16,6 ! new Moduli of rupture
TBDATA,17,6
TBDATA,18,6
hope this helps

 

[Mahender]

Dear Mr.Vogtlaender and other members of this thread, I am also having the same problem, but want to know how to see the values in the table data, i.e, what does the values signify? where from can I get the data for the annealing. Can you please help me.
Thank You
Mahender