[TheForge] Re: triangle bells/rebar

[Andy Vida]

Mike Spencer wrote:

>Is a tube a uniform beam? 

	In principle, yes.  Cross section doesn't matter in theory.
	Irregular, imprecisely, or randomly defined cross sections
	become problematic in terms of calculating bending moments
	in the real world, but in theory anything with a uniform
	cross section can be a beam.  Actually, anything that can
	bear a load can be a beam, in theory or otherwise, but the
	restrictions are imposed for ease of computation.

> That seems to be implied
> by using the equations for (typically tubular) chimes.  I would guess
> -- leaping over very low buildings with a running start here -- that
> the nodal points would be the same but the maybe the natural
> frequencies would be different?

	The frequency defines the location of the nodal point,
	I would think, since it defines the wavelength.  The
	only other possible variable I see is whether the wave
	is standing or traveling.  I'm not sure that a uniform
	structure such as a tube will ever set up a traveling wave
	along its length.  To me, such a condition would imply
	some fundamental imbalance within that "system", so to
	speak, either in structure or of input energy.  I may be
	wrong.