Custom expansion in ANSYS

[carraway]

Hello there!
I would like to make a simulation of radiation-induced volumetric expansion of minerals by showing development of stresses in ANSYS. I have a function which describes swelling and a model of polycrystalline rock, my guess is that I should somehow modify built-in tools like thermal expansion and make it develop by my function. My question is how do you simulate default expansion? Are there any related sources?
Thank you for your answers!

 

[rickfischer51]

By default expansion I assume you mean the thermal expansion due to a temperature rise. Think of the thermal expansion coefficient as a general expansion coefficient. The coefficient with have two terms, a thermal term and a radiation swelling term. The thermal term is equal to alpx. Use your swelling function to calculate a swelling strain. Then determine the swelling coefficient as follows: ε_swell=α_swellxΔT →α_swell=ε_swell/ΔT. Add alpx to α_swell to get the general expansion coefficient. If the temperature and radiation are uniform over the entire model, this is a hand calculation. Otherwise you have to make the calculation on an element basis and create a unique material for each element. This is easy to do with some APDL. If the model is large, you will need to use vector operations (*VGET, *VOPER, *VFUN,etc) and implied loops to speed things up.


Rick Fischer
Principal Engineer
Argonne National Laboratory