Ansys beginner: How to model twisting pipe using thermal?

[ShaneUCB]

First off, I just started using Ansys about a month or so ago and I'm trying to learn as much as I can with tutorials, etc. However, I need to at least start my project. I'm trying to model the way a plant rotates toward the sun. I basically just need a starting point. That is, I need to model a simple pipe, and twist it.

I figure the best way is to a) use shells and b) use a thermal material, and have the elements expand along a certain path so as to replicate the growth of the plant in such a way that provides the twisting motion.

I've modeled my pipe as a cylindrical shell, I've meshed it, I've chosen Shell64 (I think?) as my elemnt, and an isotropic linear elastic + isotropic thermal material. After fixing the base, I tried placing a temperature along a line on the surface parallel to the cylinder axis. I can solve it but none of the elements expand like I would expect. So I guess my questions are:

1) Why aren't they?
2) How to I take this to the next step and apply a temp in such as way as to provide a twisting motion?

Thanks a bunch. Sorry if these are stupid questions, everyone has to start somewhere. I miss Pro/Engineer already

 

[Drej]

>That is, I need to model a simple pipe, and twist it.

This is easy enough. Create your model from structural shells (if shells are applicable to your geometry). You can use any number of lower (63) or higher (93) order shells to do this. You don't need thermal properties to induce twist, just apply a torsional load/displacement to the cylinder.

 

[ShaneUCB]

Drej,

Yes, I can do it that way. However, in trying to simulate how the plant actually moves (expansion of certain cells) the thermal route is more analagous to what I want to do. The reason for this is the fact that when all is said and done, I need to calculate the energy required to rotate the plant VS not rotating it. Although I guess I could do this with a mechanical force as well, couldn't I?

Thanks.