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Ned Simmons wrote:
In article ,
says...

Bill Schwab wrote:

I fear you are mixing models in a way that does not work. You compute
support reactions based on the ends being fixed horizontally, and then
model the deflection based on a cantelever beam.

The cantilever beam only represents part of the vertical member: the 14'
from the horizontal to the ground. I have made an imaginary cut 14' from
the ground. This point can move horizontally, but has a moment and shear
force applied to it. With a bit of spatial twisting and turning in my
mind, I believe this 14' section can be modelled as a cantilever. The
fact that the root moves horizontally while the tip is fixed doesn't matter.

But you've got the cantilever backwards. Your calculations
would predict the deflection at the base of the column as a
result of F3 if point Z were fixed (moment connection) and
if the base were free, which is not the case at all.

I don't believe this matters. The formula gives the deflection of the
cantilever tip relative to the root. It doesn't matter which moves. You
can build a system of guide rails such that a pin joint is at the fixed
end of the cantilever, and the root is allowed to move transversely, but
not rotate. In this case the formula is still valid, and this is the way
in which I'm using it here.

If anyone has a counter argument or proof I'd be very interested to hear
it. Or if anyone does the calculation by different means I'd like to
know your result, too.

Chris