Getting stress tensor

[aminhed]

Hello friends

I modeled a power screw and its nut in mechanical desktop and imported this model into ANSYS 13.

I want to locate the stress concentration and also stress tensor over the screw. Attached photo is an overview of this model.

1- There is contact between screw threads and internal threads of nut.

2- The mechanism of this nut and screw is that, nut just can rotate around its longitudinal axis and the screw is constrained from two key ways, so that it just can move along its longitudinal axis.

So the rotation of nut will cause the linear movement of the screw and it is the main idea of using power screws.

I used Static Structural module to do my analysis,but the problem is that, when I use remote displacement to define supports and set the rotation degree of the nut and y movement degree of the screw as free, the analysis gets wrong and there is no stress tensor or contact force between these two parts.

Does anybody have an idea about defining supports or maybe using other modules to do this analysis?

Thank you in advance.