Hi StructureDr,
There is a paper on this. Please see link below for the paper. Refer to Table 2 of the paper, there is a recommendation of structural properties for various limit state.
We will provide the wind tunnel specialist with 2 set of dynamic properties.
For Service - Partially...
Hi RohanDutt,
I have opened your model. Run a modal analysis with vertical mass turned on and you will see where the huge instabilities come from. Your upper floors seems to be 150 mm thk. timber floor without any beams. Are you sure it is going to take ur 1.5 kPA SDL and 2kPA Live Load?
Hi Saadpervez1,
When you look at eigenvalue (i.e time period or frequency) - Etabs provide them in terms of unit of time (say seconds for period and Hz for frequency) but my when displaying the mode shape in tabular form, it provides mode shape of every floor in terms of mm...Now the question...
This is to do with poor structural framing? Do you have an eccentric core? Try to look at the difference between the centre of stiffness and centre of mass. If the eccentricity is huge, then it is not surprising the you have torsional as your dominant mode.
Hi Guys,
I am curious why does ETABS report mode shape with units. Back in my uni day, I was constantly reminded by my professor that the mode shape is mathematically just an eigenvector...It does not have "any" real magnitude and only indicate the shape of the structure.
Is there any reasons...
Hi Guys,
I am sure most of us here are familiar with the stiffness modification factor stipulated in ACI 318-14.
For beams and columns, the application of stiffness modifiers can be easily incorporated into ETABS analysis by modifying the respective moment of inertia.
My question here is how...
