"ext. gauge length: 4in"

"Spec. gauge length: 2in"

"thickness: 0.037in"

"width: 0.5in"

now, the machine starts to pull the beam apart, and the first reading comes out as "-0.955460" at a load of 0.99328lbs. so ~1lb force on a aluminum beam should cause basically no extension or deformation. the next several entries look like this

displacement load

-0.955440 0.9664

-0.955260 1.10066

-0.955110 2.09395

between these there are about 2700 entries... but here are the last few

displacement load

-0.493260 894.494

-0.49310 893.1520

-0.492770 889.93

-0.492770 887.78

beam breaks.......

ok, i am kind of confused on how to interpret this data. first off i need to convert the displacement in to stress.... what i have so far is that i take the original displacement, (-0.95540) and subtract it from itself, leaving a displacement of 0. makes sense right?

now i go down the list a subtract that same number from the corresponding displacement, so the last entries look like this...

0.4622

0.4624

0.4625

0.4625

0.4629

now, does this means just before the beam broke it was displaced, or extended 0.4629in??? does that make sense for a 4in aluminum beam to extend that much? need some elite materials guys for that one! haha. all kidding aside, to find the stress would i then divide that number by the original beam length, 4in?

any help would be appreciated, maybe some of you have dealt with this before!

thanks

jared