Aluminum Box Beam Load Bearing Properties

[David Love]

An aluminum pneumatic rib press.  Two aluminum box beams (upper and lower)
held together by vertical pieces of aluminum angle "iron" with room for a
single 2x4 cut into the shaped caul between which the rib, soundboard panel
and pneumatically operated hose would go.  Nice and light and easily
storable.  Just trying to figure out how big the box beam needs to be, 1.5"
wide is all I need in that dimension so the key, as it always is with beams,
is the height.  The caul would add a bit of stiffness to the assembly as
well.    

David Love
davidlovepianos at comcast.net 
www.davidlovepianos.com

-----Original Message-----
From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On Behalf
Of Ron Nossaman
Sent: Friday, December 14, 2007 9:05 PM
To: Pianotech List
Subject: Re: Aluminum Box Beam Load Bearing Properties


> Who can tell me about the load bearing properties of a 1.5" Aluminum box
> beam with 1/4" sides.  Supported at either end of a 4' beam how much
> deflection will occur per lb in the center of the beam and at what point
> does it reach failure.  
> 
> David Love

I can't tell you specifically, but I can make a list of most 
of what you need to know to find out. The first thing you need 
is the MOE of the material. 2024 SO is considerably different 
in load bearing capacity and maliability from 7075 T6. 
What'cha building?
Ron N