I have thermal gradient diagram .How to calculated DT-G in temparate loading ? Thank you

The input "DT-G" can only be used for constant temperature.

For considering a non-linear temperature gradient you need to follow these steps:

1.) Define the gradient in the Modeler within a reference-set (type "Temperature Points") by a continuous series of reference points from top to bottom. Note to assign an attribute-set to the reference-set of the temperature points. 

2.) In the Analyzer define a load case of the type TNLIN (menu “Initial stress/strain” -> Temperature loading (non-linear)”). In this load case just refer to the attribute set of the gradient.

3.) Calculate this load case in the Schedule actions with the action “Calc”.