fire simulation

Hello

My aim is simulate the structural response of a plate with pressure applied under fire condition in abaqus


To that extend I know how the temperature variates in time (known T(t) t from 0 too 3600 sec) also I know the material properties and Sy to every temperature.



I thought that the best way to do this is by applying the T(t) as BC in the structure and use coupled temp displacement in one step.



But I don't know if this approach is correct.



I also tried to solve only for the temperature curve in one step without the pressure  using coupled temp disp and then insert the results in a 2nd step general static where I applied the pressure load.



I got different results for both approaches.



Does anyone know what is the best approach for this kind of problem?



thank you for your time