I got the Damping matrix using the command:

FINISH

/AUX2

file,file,full,

hbmat,HBMstiff,txt,,ascii,stiff,yes,yes

hbmat,HBMmass,txt,,ascii,mass,yes,yes

hbmat,HBMdamp,txt,,ascii,damp,yes,yes

FINISH

If i use this command in Modal analysis solution, Considering it as Damped in Solver controls and giving the mass and Stiffness coefficients, I am getting Damping , Stiffness and mass Matrices.

But If I do the same in Harmonic Analysis, I am getting only Mass and Stiffness Matrices.

I have in my notes the following (but cannot test it now).

You need to add  after the Modal block the following code in your APDL macro and run all.Of course you have to add structural damping to have in the .full file the damping matrix available.

Then the files should be written for your Ansys directory in txt format.Hope it is okay, anyway add a comment here.

FINISH

/AUX2

file,file,full,

hbmat,HBMstiff,txt,,ascii,stiff,yes,yes

hbmat,HBMmass,txt,,ascii,mass,yes,yes

!! hbmat,HBMdamp,txt,,ascii,damp,yes,yes !?

FINISH

Thank you,  I have given the sitffness and mass coeffecients and damping ratio and used the command.I tried using the commands wich you gave but unfortunately I am geting only mass and stiffness matrices,but no damping matrix. Is there any other way I can get it?

Hi Bhargava,

Can you try the code below? I was using this code in ANSYS WB.

! Stiffness

*DMAT,MatKD,D,IMPORT,FULL,file.full,STIFF

*PRINT,MatKD,Kdense.matrix

! Mass

*DMAT,MatMD,D,IMPORT,FULL,file.full,MASS

*PRINT,MatMD,Mdense.matrix

! Damping

*DMAT,MatCD,D,IMPORT,FULL,file.full,DAMP

*PRINT,MatCD,Ddense.matrix

I have no Ansys access at the moment, but realize that you may not be able to get that C matrix by simple way. If nothing else works, an idea is that you try to rebuild your C matrix with the input data you have and the specific model of damping that you are using.

For it, I recommend you to look at some technical documentation on damping model you use in Ansys (see e.g. in the old document  http://easc.ansys.com/staticassets/ANSYS/staticassets/resourcelibrary/confpaper/2002-Int-ANSYS-Conf-197.PDF) and look at equations around eq. (28) to see what you can do.

Anyway consider to share here your progress with this.