Bending force query
Bending force query
(OP)
Hi All,
I've been trying to figure out a way to calculate the bending force required to permanently deform a steel plate.
The process involves pressing a 300mm wide, 2mm thick s275jr plate into a shaped die. The desired outcome is to form a 90mm radius that passes along the entire width of the plate.
The bottom die will have a radius of say r90+thickness, and the punch will have a rad of r90. The plates internal angle after forming will be 90^.
I have looked up a few equations, but they don't seem to make sense when I pick them apart, and the forces calculated are way too low in my opinion.
Would the correct way be to approach this as a deflection and calculate the plates second moment of area, or do a cross sectional calc and sweep this around the curve?
Any help would be much appreciated
:)
I've been trying to figure out a way to calculate the bending force required to permanently deform a steel plate.
The process involves pressing a 300mm wide, 2mm thick s275jr plate into a shaped die. The desired outcome is to form a 90mm radius that passes along the entire width of the plate.
The bottom die will have a radius of say r90+thickness, and the punch will have a rad of r90. The plates internal angle after forming will be 90^.
I have looked up a few equations, but they don't seem to make sense when I pick them apart, and the forces calculated are way too low in my opinion.
Would the correct way be to approach this as a deflection and calculate the plates second moment of area, or do a cross sectional calc and sweep this around the curve?
Any help would be much appreciated
:)





RE: Bending force query
If I sound a little abrupt this is first year stuff.
Cheers
Greg Locock
New here? Try reading these, they might help FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm?
RE: Bending force query
what's the value in knowing the force to bend something if you don't have the machine ? If you have the machine, why do you need to know the force (either it will or it won't be able to do the job).
another day in paradise, or is paradise one day closer ?
RE: Bending force query
Cheers
Greg Locock
New here? Try reading these, they might help FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm?
RE: Bending force query
"What's the value in knowing the force to bend something if you don't have the machine?" The answer might be "to know what machine to buy".
Anyway- one possibility, figure the total work that must be done to form the plate, figure distance the dies have to move in doing that, figure peak force is at least double the average force, and see where that gets you.
That plate size is small enough that it wouldn't be too hard to do some testing- cut dies out of wood and try a strip 1" wide or so first.
Actual metal forming for that application may involve putting it through rollers rather than pressing.
RE: Bending force query
You could send the part out for a die quote and the toolmaker will tell likely you tonnage required.
RE: Bending force query
another day in paradise, or is paradise one day closer ?
RE: Bending force query
B.E.
You are judged not by what you know, but by what you can do.
RE: Bending force query
RE: Bending force query
RE: Bending force query
another day in paradise, or is paradise one day closer ?
RE: Bending force query
B.E.
You are judged not by what you know, but by what you can do.
RE: Bending force query
In my experience they always know what the press will do once, but rarely know what it can do an unlimited amount of times without damage.
Come on guys, straightforward question here. Help the guy learn something.
RE: Bending force query
Thanks again for the responses.
Kind regards
RE: Bending force query
By "the bend would not be true" do you think the program was saying it would tear, or just not be a smooth curve across the both 300 mm sections?
RE: Bending force query
It would not be a smooth curve, it would tend to bend more in the middle because the die would not support it.
B.E.
You are judged not by what you know, but by what you can do.
RE: Bending force query
example
https://mathtab.com/app_id=4104