I have two towers, a monopole and lattice work (made of steel).

I was wondering what information would I need to calculate to be able to calculate how much force each tower would be able to handle?

Thanks.

Surface area, coefficient of wind resistance, height (to calculate the turning moment), and some understanding of the weight and depth of the foundation (to determine its ability to resist the turning moment).

Thanks, would I be able to use the same formula?

You have cited the formula for wind resistance. Of course the kicker is figuring out what C_d is for the tower geometries.

That's true. Cd for the monopole would be a basic cylinder, but for lattice work, that would be long.

What would the formula for the wind force be? Thanks for all your help!

It would depend on the geometry of the tower. You basically multiply the force on each piece by its height off the ground. If the tower has a fairly uniform cross-section, I would simplify it by modelling it as if all the force is applied half way up the tower. In other words:


Moment = F_d * H/2 = \frac H 4 \rho v^2 \sum C_d A_i

for all pieces.

One other point - remember that the wind acts on the lattice piece on both sides of the tower - that is, it pushes against the front of some and the back of others.

Where are you finding you values of C_d from? Also, what wind velocity are you assuming?

Well, I'm going with the C_d values from my fluid dynamics textbook, wind velocity = 30 MPH