So if I have this right the bow is in the 10' dimension, so if you put a 5'
long spacer on the ground at each 5' end and rested the 5' ends of the plate
on them, with the bow up, and then stepped on the plate really hard in the
center it would now be straight? If so, a concentrated load of 10,000 lbs
would deflect it 5.9" and the maximum stress in the plate (at the center)
would be 53,000 lbs which should be about the yield point. So get two 6"
thick beams to support the ends, put a 5' long plate a foot or so wide and
at least 3/4" thick across the middle of the 10' span parallel to the end
beams to spread the load in the 5' direction, and drive over it with one
front tire of your semi. There should be just enough room to get one tire
on the middle plate and have one end of the plate just clear the other front
tire, and you should have more than 7" of ground clearance. I'd make a
short ramp to get the tire up to the level of the plate, then drive across
until the tire almost comes off, then remove the ramp and back off the side
you came up on so when it unloads and snaps and bounces it won't hit
anything on the underside of your truck. Hopefully the tractor is heavy
enough to flex the plate all the to the ground which should just make it
yield. If not, load up the trailer :-). If the first pass doesn't get it,
add a 1/4 or 1/2" spacer to the top of each end beam so it flexes a little
further and try again.

Or drive over it with your biggest forklift if it is heavier, but you will
have all the wheels on the plate at once and the load will be spread out
much further. Or use the forklift to stack up 10,000 lbs of scrap steel in
a line across the center one pallet or chunk at a time. Or put a column in
the middle with a jack and a loop of chain running from each end over the
top of the jack so it looks like you are cocking a giant crossbow. I think
that would be very dangerous, though if anything slipped so don't do that.
However you flex the plate, you need at least 10,000 lbs of force and you
need to flex it about 6" to get it to yield (assuming a yield strength of
about 50 ksi).

-----
Regards,
Carl Ijames
"Ignoramus23452" wrote in message
...

On 2013-10-19, Ignoramus23452 wrote:
I have a 3/4" thick steel plate that is 3/4" thick. It is bowed in the

Sorry. I just came home from a little party, that's why I mis-wrote
some things.

5x10 ft plate that is 3/4 inch thick.

middle along its length. The worst un-straightness is in the middle
and it is appx. 1/4". I would like to straighten it. How can I
realistically do it, if at all.

To add to that, I can somewhat deflect this plate using jacks and
chain.

i