Afraid I'll have to defer to someone with Patran experience. In most software packages that I use, you can apply a unique temperature to individual parts. The set-up can be non-sensical. For instance, if I want to create a beam with a stiffness of 1000, I give it a cross section resulting in an easily calculated I, a length dependent upon how long it is in the model, and then set the E value to whatever it needs to be so that EI/L = 1000.
The same is true if I want a certain preload. F=kx, so I make the stiffness "k" calculable. I know what "F" needs to be since it is the preload I'm looking for. Then, all I have to do is determine how to get the "x" that I calculate.
Well, since "x" is the strain that I need in my element, I just have to insert a coefficient of expansion "a" in inches per degree C (or whatever temperature units) and apply the delta temperature that, when multiplied by the thermal expansion, results in the "x" that I need.
Sounds much more complicated than it really is.
Hope this helps more than it confuses...
Garland