Roark's Formula Plate Fixed On Three Edges
Roark's Formula Plate Fixed On Three Edges
(OP)
Does anyone have Roark's Formulas for Stress and Strain? I need equations for maximum bending moment, shear, and deflection for a flat plate fixed on three edges and free on one edge.






RE: Roark's Formula Plate Fixed On Three Edges
btw, how loaded ? uniform pressure ??
Quando Omni Flunkus Moritati
RE: Roark's Formula Plate Fixed On Three Edges
RE: Roark's Formula Plate Fixed On Three Edges
www.usbr.gov/pmts/hydraulics_lab/pubs/EM/EM27.pdf
RE: Roark's Formula Plate Fixed On Three Edges
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RE: Roark's Formula Plate Fixed On Three Edges
http://directives.sc.egov.usda.gov/OpenNonWebConte...
RE: Roark's Formula Plate Fixed On Three Edges
BA
RE: Roark's Formula Plate Fixed On Three Edges
Great links.
I have been 'reading-up' on the behaviour of small thin-slabs under various load conditions for over a year and I think I am slowly getting 'there'. What I found surprising, given the number of enquiries there are for moments on slabs - UDL, concentrated, etc. - there was, or is, a lack of good worked examples on the internet. I have read Roarke, played with the on-line calculators and read as many books as I am to get on the subject and I could not find one good worked-example of a concentrated-load on a concrete two-way slab, let alone the load in, say, the corner. BS8110, and I am sure other codes are similar, have an excellent design method for two-way slabs under a UDL; so why is a standard-method for a concentrated load design, or a three-side supported slab design so difficult to obtain. Of all the engineer's I know (two) neither use a consistent design method and the results are not equal. Computer analysis is no good without understanding the method.
Hopefully, there will now be a deluge of worked examples thrown this way but it is hard trying to learn a method without good examples.
Great forum.
Regards
RE: Roark's Formula Plate Fixed On Three Edges
There is no standard method because the structure is highly indeterminate and is not fully defined by the dimensions and load on the plate being analyzed. Tables often consider an edge to be fixed, simply supported or free. In real plates, fixed and simple supports are rarely if ever found.
A concrete slab or wall responds to load according to the way it is reinforced. Two engineers may come up with different solutions, but that does not mean that either is wrong. There must be considerable flexibility in the way a highly indeterminate structure is analyzed.
BA
RE: Roark's Formula Plate Fixed On Three Edges
In my opinion, it's pretty over rated. It has a lot of chapters I never use, some blatant typos and some formulae with so many variables that they're darn near unusable. It's nice to have so much information in one reference, but by it's nature, there's a lot of important background missing.
For plates, I like the Bureau of Reclamation tables by Moody. For other cases not covered there, I bought a copy of Timoshenko, "Theory of Plates and Shells." Note that both of these references provide the "native code" for Roark in a much more complete format.
RE: Roark's Formula Plate Fixed On Three Edges
RE: Roark's Formula Plate Fixed On Three Edges
Quando Omni Flunkus Moritati
RE: Roark's Formula Plate Fixed On Three Edges
For what it's worth, there is apparently a great deal of variation in the different versions of Roark's, and people evidently are quite opinionated as to which ones are good and which ones aren't. I've heard good things about the 8th (current) and the 4th edition, while the 5th edition I've seen described as "best used as a doorstop". So take that for what you will.
Brian C Potter, PE
http://simplesupports.wordpress.com