Erik Kostson
Ansys Employee

First we should say that there is no thermal stress, with that meaning that temperatures do not causes stresses (they cause strains, thermal strains), hence why there is no such result output. To show this, say a body is not fixed and hence completely free to expand we will expand (thermal expansion) and develop thermal strains (alpha_thermal_expansion*Delta_Temperature - this is what we plot only in ansys with thermal strains results) but of course no mechanical stresses will be present. We get mechanical stresses due to thermal loads when we have constraints and other surrounding effects prohibiting free thermal expansion of a part. Say we have a 1D stress (say a 1D rod) that is restrained at both ends, and then we apply a temperature to it. In this case the mechanical strain is equal and opposite in sign to the thermal strain and we then get of course a compressive stress in the rod. You can try and study this in ansys and compare to hand calculations, that is very good exercise.

I would also suggest to go through this course that will explain this:
So one can choose to look at VM stress or minimum principal stress, or normal stress (say radial direction),etc, and that will stress caused by thermal loads/strains.

You have also asked a similar question on your other post so please be mindful not to open multiple post with similar questions.

All the best