Tall building structural thermal analysis
 

I am doing structural-thermal analysis on a collapsed high-rise building (47 Floors). The collapse was due to the fires on Floors 7 through 9 and 11 through 13. To simplify the problem, I only analyze the structural response of lower 16 stores to the heating from the fires on Floors 7 to 13. The model used the temperature dependent mechanical properties of the steels, welds, and bolts used in the construction of this building including elastic, plastic and creep properties. Also Component structural analyses were conducted to identify critical behavior and failure mechanisms that could have contributed to the
global structural response of the building. These component analyses included (1) buckling of a core column, (2) beam-to-girder connections under thermal loading, and (3) girder-to-column connections under thermal loading. The thermal load input into this model was obtained from special fire structural software.

I would appreciate if anyone having done similar analysis can give me some clues how to design nonlinear analysis steps for this problem. I will use ANSYS APDL to build the model. Thank you very much.