write user element in ANSYS

[webkaktus]

I try to write user element, but I have problems. Please help me!

I use ANSYS 10 and I already compiled and linked existing user elements (user100 as mass21 and user 101 as link8) in ANSYS 10.

Now I try to write my own routine for my element (which takes into account isotropic and kinematics hardening and/or softening with the damage mechanics - hexagonal element), but I don’t know how. In Guide to ANSYS User Programmable Features book is a lot of subroutines for creating and supporting user elements, but I don’t understand them exactly. I have problems to find what means many of variables. I also don’t know how to specify input and output arguments.

Could anyone tell me where can I find description about variables and arguments?

Any suggestions how I should start writing user element?

webkaktus

 

[wootletootle]

Hi, I am also proceeding down this route. I suggest we
pool our experience. Ansys certainly does not make it easy
for somebody to implement a "non-standard" application.
I have had some experience with the Abaqus user element
UEL, so I know more or less what is required.
My aim is to use Ansys uel to incorporate absorbing
boundary conditions in a structural model. My plan is
roughly as follows

(1) Write the material model in fortran F90 and include
the object files in a user library. Copy the library
and any modules to the Ansys working directory.

(2) Write the element integration routine as part of
uel, or as an (F90) subroutine. The model supplies
stress and tangent tensor. Adjust the element
matrix to take into account the radiation bc.

(3) Return the nodal RHS and element matrix to Ansys.

(4) There are a lot of other variables which can be
passed into and out of uel. Try and work out which
of these are really necessary by means of a
simple example eg uniaxial plain strain. I think
the nodal RHS and the element matrix are the only 2
really important quantities.

If you are interested in following this up, reply here.

Cheers,
Roger Young.