--- David Jordan <wa3gin@erols.com> wrote:
> ...and what happens to those numbers when the wind starts blowing at
> 50 mph?
>
Let me tell you, my Statics professor (Is that old fossil still
alive??) would be proud that I even remember as much of what he taught
me as I've already told you. We're really digging into the dark ages
now.
IF you could assume that the base of your guyed tower was not fixed in
position, but instead was allowed to slide frictionlessly in the
horizontal plane, and assuming that the wind was 50 MPH at all points
along the total height of the tower, then the increase in guy tension
due to the wind would be basically equal in all three guys because the
tower would deflect horizontally an equal distance along it's height.
BUT, since the base of your tower IS fixed to one degree or another
(set in concrete, single pin, etc), the horizontal deflection of the
tower will be more at the top than it is at the bottom, so the increase
in guy tension will be somewhat more in the upper set of guys than it
is in the lower set. Being a tweek and not a structural engineer, my
guess is that this difference in guy tension will still not be a very
significant bearing on the overall problem.
Actually, I'd gladly give you some real numbers on this, but I ran out
of sufficient significant digits on my 5 inch Castell slide rule to
complete the calculation. I really keep the slide rule and a 4X500 on
my desk so young puke engineers can say "Wow! What are those?" Then I
can proceed to impress them with my vast and limitless knowledge of the
inane and arcane.
73,
Brad, W5CGH
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