On Mon, 27 Feb 2006 16:02:51 -0500, clare at snyder.on.ca wrote:

On Mon, 27 Feb 2006 15:14:24 -0500, Curtis Scholl
wrote:

Cla

Looking at the calculations for the spar, spar.pdf I do not see your
interpretation. The 67000 psi value is Bearing Ultimate, not tensile.

A MATWEB lookup is in order:

6061-T6

Tensile ultimate: 45000
Tensile yield : 39000

Bearing ultimate: 88000
Bearing Yield : 56000

The values presented in the spar calculation are correct, and the
bearing ultimate of 67000 is below spec.


Thjat may well be true, but is "bearing strength" the proper
charachteristic of the material to be used in this calculation?

As I said - not an engineer - just asking.
Please explain for the rest of us how the bearing ultimate and / or
yeild values impact the calculation, vs tensile.
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bearing strength

The maximum bearing load at failure divided by the effective bearing
area.
In a pinned or riveted joint, the effective area is calculated as the
product of the diameter of the hole and the thickness of the bearing
member. ASM, 1



How does this impact the failure of the wing structure by buckling and
failure of the main spar???
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