Natural frequency of high rise building

[nathan7]

Hi all,

To estimate the natural frequency of a tall structure, literature suggest to use the formula 46/H.

This is a general formula derived from tests on real structures. This formula is valid for structure which have been designed to perform under service and ultimate loads.

When I'm undertaking a preliminary design and I'm checking if the core structure is big enough i need to calculate the period based on the size of the core (which might be too small) and on the square root of k\m

Does anyone know a formula to work out the natural frequency of a tall structure simply base on mass and stiffness?

Regards

 

[structSU10]

you can use Rayleigh's equation:

https://etd.ohiolink.edu/!etd.send_file?accession=osu1316473829&disposition=inline

see page 8 of the pdf for the equation. It does require an analysis to see deflection of the structure under lateral loads.