Aluminum compressive failure

[NikonF6]

Aluminum A380 or like.
At which static compressive stress it will fracture?
At which compressive dynamic load (say Smin<0 and Smax<0) it will fracture. Any data will help.

Thanks

 

[curiocity]

Not an expert. But according to Alloy Digest, Aluminum A380 Alloy has a tensil strength, psi of 42000 (typical cold chamber as-cast properties)

 

[realtime2]

Generally the compressive stress strain curve is a mirror image of
the tensile stress strain curve up to maybe 1% plastic strain.
Thus you will get yield and plasticity at about the same value as
in tension. Due to plasticity you will get an increase in the thickness
of an assumed cylinder. There will be no "Ultimate stress" because in
tension the ultimate is due to necking of the test specimen. Usually in
a cylindrical axially loaded specimen the failure is by buckling, or
shear at 45deg, or barreling, but often this may be a test end-condition
or alignment problem.

If you are squeezing a cylinder of aluminum, due to end conditions
at the squeezing plates, it can "barrel" out in the middle
(the area increase is not uniform - more in the middle of length).
The barreling will cause tensile stresses to occur in a different direction
than the applied compressive load. These tensile stresses will eventually
"fracture" the barrel - sideways (or some angle towards sideways).
See tests on concrete cylinders.

If due to surrounding constraints it cannot "barrel" it will not fracture.
E.g. : hydrostatic: put a cube of it in a liquid pressure vessel and take it up
to 1 M mpa. Result: nada, though it might be a bit smaller than when it was
put in.
Hope this helps.