Originally posted by: Rhombuss
Yes, from Canada. Actually, we have very sophisticated and thorough steel and concrete design codes in Canada. The American steel code primarily follows the ASD (allowable stress design) standard, which isn't the most up-to-date standard available. We follow a strict limit-states methodology, which I think is what the American codes lack, although I'm aware that a steel limit-states design code was issued a number of years ago to no avail.
Definitely using steel. If reinforced concrete was used, the amount of reinforcing required would probably be enough to build a separate tower .
Originally posted by: alphatarget1
sweet, I thought there weren't many civil/structural engineers on these boards.
1) I don't know much about wind loads (not that i know a whole lot about earthquake either), but as long as the resonant frequency is low it should be fine... am I right, or am I way over my head?
2) Here is an idea, have a ME draw and run a COSMOS analysis on a blade assembly, scaling down (dimensional analysis) things so the analysis is shorter.
3) 2MW? wow, I didn't know wind turbines generate that much power! That is a lot of weight though, I agree, P-Delta is necessary if there is a significant amount of deflection at the top. How much deflection are you anticipating from the wind load at the top?
Where do you work, if you don't mind me asking? I think California schools emphasize a lot more on earthquake than anything else.
The sway of the tower back and forth will largely depend on the wind area (which is why I posted in the first place). There doesn't seem to be much literature in how to treat it from a structural foundation point of view. Also, I may have neglected to mention, but this tower is to be installed off-shore. Thus constant wave loading and immense wave loading from storms will be another factor on the lower elevations of the tower. Considering hydraulic forces are much greater than wind forces, it may be significant.
We don't have inhouse mechanical engineering consultants (at least not directly for our telecommunications division, unfortunately), but that would be an interesting thought. Hopefully the manufacturers have already done the leg work in this area, and are willing to provide that data.
Anticipating the deflection to be on the order of 'feet' during max gusts (that's assuming total deflection range, which considers sway back and forth over the stationary point).
I'm from Toronto, which isn't an earthquake design zone. You're correct, west coast institutions both in Canada and the US highly emphasize structural and geotechnical dynamics for earthquake analysis. It's amazing these days what can be done to dampen dynamic shock from earthquakes. I've seen some buildings being supported entirely be hydraulic foundations that reduce impact loading on the building columns - very neat!