Temperature load -ETABS 1

[N G P]

I was involving in the design of a three storey building the length of the building in the ground nd first floor is more than 80m and the length of the roof floor is 35 m. Although we are providing some insulation for the heat protection the temperature in the building location reaches up to 52 degrees celsius in summer season.
I was trying to apply temperature load for the exposed slabsin ETabs. The slabs are exposed on the top side only and the inside it will will be air conditioned. I couldn't find an option in a etab to provide non uniform temperature load considering the heat insulation.
However I provided 15 degree celsius uniform temperature change to all the exposed slabs. But I was getting enormous axial forces for the slabs and the connected beams and eventually getting huge amount of reinforcement for those beams and slabs. I doubt the procedure that I followed and I missed something.
Could any one mention how to apply temperature loads in the design of buildings in etabs.?!

 

[N G P]

Helloo..

Anyone there?

 

[Agent666]

I've never used Etabs for this (wasn't even aware you could apply temperatures), but one comment I'd make is the possibility that you are seeing the larger forces because you also need to apply the temperature change to the beams supporting the slabs at the same time, you only reference that you are applying the temperature effects to the slab?

 

[N G P]

Hi Agent 666,

I have applied the temperature load to the slabs and the beams as well. But, I have some slabs exposed and some slabs not exposed to weather at the same level. I applied load only to the exposed area. And I am getting concentrated stresses on the joints between these slabs. That stresses gives huge amount of reinforcement.

 

[Agent666]

I'm sure this result is somewhat due to the sharp gradient of temperature differences you are applying between the two areas.

In reality I'd imagine the higher temperature of the slab would raise the temperature of the adjacent cooler slabs for a less severe temperature gradient.

 

[N G P]

The sharp gradient in the appllication of the loads is the problem.These junctions are observed to recieve the concentrated stresses.