Roark Flat Plate Question
Roark Flat Plate Question
(OP)
I have a what I feel is a stupid question.
I have a flat plate 18"x72"x0.375" thk. When using the Roark formulas, which dimension is "a" and which is "b"?
Thanks
I have a flat plate 18"x72"x0.375" thk. When using the Roark formulas, which dimension is "a" and which is "b"?
Thanks






RE: Roark Flat Plate Question
In some cases, "a" will always be the longer dimension, and you'll have tables of a/b or b/a that don't extend beyond 1.00.
In some of the Roark load cases, there will be a section defining all the variables, etc., then tables of different load cases, and you may need to refer to that section.
Don't confuse the circular-plate tables with the rectangular plate tables.
If that doesn't help, let us know which edition of Roark's, which table, which load case, which page, and maybe somebody can look it up.
RE: Roark Flat Plate Question
RE: Roark Flat Plate Question
RE: Roark Flat Plate Question
RE: Roark Flat Plate Question
RE: Roark Flat Plate Question
If they did have a set of factors for a/b=4, it's going to approach the one-way span case.
RE: Roark Flat Plate Question
RE: Roark Flat Plate Question
another day in paradise, or is paradise one day closer ?
RE: Roark Flat Plate Question
RE: Roark Flat Plate Question
TTFN

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RE: Roark Flat Plate Question
look at a strip 1" wide, 18" long, 15 lb/in load, M = wL^2/8 = 608 in.lbs, stress = 6M/t^2 = 26 ksi ... sanity check.
note this is the roark solution for a infinite aspect ratio (a/b) ... 6/8*wL^2/t^2
another day in paradise, or is paradise one day closer ?
RE: Roark Flat Plate Question
Here's what I came up with:
Roark Case 1a
ymax = alpha*q*b4/Et3
Sb = beta*q*b2/t2
Carbon Steel Plate is 72"long x 18" wide, x 0.375" thk.
Pressure on plate, q = 14.7 psi
Max. Allow Bending Stress in plate = 18,000 psi
If I stiffen the 72" length with 3 stiffeners, the length of one "panel" is 18".
a/b = 18"/18" = 1
alpha = 0.0443
beta = 0.2874
ymax = 0.0443*14.7*184/30E6*0.3753
ymax = 0.04321in
Sb = 0.2874*14.7*182/0.3752
Sb = 9,734 psi
RE: Roark Flat Plate Question
TTFN

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Need help writing a question or understanding a reply? forum1529: Translation Assistance for Engineers
Of course I can. I can do anything. I can do absolutely anything. I'm an expert!
RE: Roark Flat Plate Question
another day in paradise, or is paradise one day closer ?
RE: Roark Flat Plate Question
RE: Roark Flat Plate Question
Thanks
RE: Roark Flat Plate Question
but this looks such a change from the previous, that maybe you say "call me when you guys have a serious idea" ?
another day in paradise, or is paradise one day closer ?
RE: Roark Flat Plate Question