Hello
Why do you need T-section as concrete column?
I think sap2000 can't design concrete column defined as T-section. Check what types concrete design supports.
I am not sure what you are looking for, or why you need that.
But if you are new to ETABS there is good Watch and Learn tutorials on their site.
http://www.csiberkeley.com/Support_WL_ETABS.html
In my country and in most of Europe, the bending moment is plot on tension side. That's convention and we are using it. Neither of us can't change that. So, depending on country where you work, use one or another convention.
Well we are learnt to be more engineers than matematicians.
If a students can understand the nature of problems there are not problems with reversing the signs of coordinate system.
Of course its not fixed. But the moment side is not fixed also.
On the cantilever beam we put rebar on the top side and moment diagram we plot also on the top side.
I plot the moment digram on tension side.
Why the moment diagram is shown on tension side?
We cover the tension with rebar, so I think that's the reason for showing the moment on the tension side.
It is clear why the torsion is developing. Try to put zero in the properties. Analysis will be completed without problems if it's compatibility torsion.
There is the equilibrium and compatibility torsion.
So I think, if the torsion is not needed for equilibrium there should not be any problems if you put 0 instead of 1.
Hi...
The earthquake waves are comming from one direction. You don't need to sum the influences from two ortognal directions.
Just analyse the influnce in two main directions (X i Y in most cases) separately.
