Plate Bending
Plate Bending
(OP)
I have attached a sketch of my application. I am trying to figure out how thin i can make the 2" plate in order to put the 10K pounds of force on the plate. There is no reason I cannot use gussets on top if that will help. The whole structure will be sitting on a platform (not suspended). I used a program while in college for this type of analysis but the name of it is escaping me right now. If you could point me in the right direction I would greatly appreciate it.





RE: Plate Bending
M = P X L
P = 10,000Lbf
L = 24"
M = 240,000In-Llbf
Z = b X h^2/6
b = 24"
h = 2"
Z = 24" X (2")^2/6 = 16 In^3
S = M/Z = 240,000In-Lbf/16In^3 = 15,000 psi
Do not use thinner than 2" unless you add gussets then the calc method changes. 24,000 psi is a fair Yield Strength for "mild" Steel which gives you less than 2:1 factor of safety.
h = square root of (6PL/bS)
Therefore, if you use "enough" gussets, the thinning of 2" plate becomes directly proportional to the square root of the ratio L/24". L is the space between gussets.
It appears you will be depending on welded structure. 1,400 Lbf/in for 1/4" weld will give a healthy safety factor for mild steel.
RE: Plate Bending
RE: Plate Bending
corus
RE: Plate Bending
If it is cylindrical, as corus suggests, then you need the formula for that condition to calculate it. Roark is an excellent source.
RE: Plate Bending
Even if it were rectangular the formula by metman must be incorrect. If the force is P = 10,000 lbf then the moment from the reaction forces at the edges must be P/2 x L/2 for a simply supported beam, or PL/4. If as I said earlier, the side supports provide some rotational restraint then the moment will be PL/8 for edges fully built in at both the centre and at the edges. The true answer will be somewhere inbetween. I'd use PL/4 to size the plate thickness. If you use gussets then the moment will be effectively reduced but then I'd consider the bending moment at the edges for a built in beam to size the gussets and welds.
corus
RE: Plate Bending
RE: Plate Bending
corus