Roark's (7th Ed.) Table 11.4, Case 2
Roark's (7th Ed.) Table 11.4, Case 2
(OP)
Roark's Table 11.4, Case 2 is for a rectangular plate with three edges simply supported and one edge free. The sketch shows the "free edge" is along the dimension "b".
For the formulas and aspect ratio (a/b) on the 3rd column to be correct, shouldn't the sketch show the "free edge" along the dimension "a"? (just like the skecthes on Case 7 and Case 10)
I would like to hear from those who are familiar with the plate theory or those who have older versions of the Roark's book where Roark is the still the original author (not Young or Budynas).
For the formulas and aspect ratio (a/b) on the 3rd column to be correct, shouldn't the sketch show the "free edge" along the dimension "a"? (just like the skecthes on Case 7 and Case 10)
I would like to hear from those who are familiar with the plate theory or those who have older versions of the Roark's book where Roark is the still the original author (not Young or Budynas).





RE: Roark's (7th Ed.) Table 11.4, Case 2
a/b 0.5 ... 1.0 ... 2.0
Beta 0.36 ... 0.67 ... 0.79
These values, and their trend, look to me to be reasonable and to reflect that the single free edge is along the "b" dimension.
(Beta is defined by MaxStress = beta*q*b^2/t^2)
RE: Roark's (7th Ed.) Table 11.4, Case 2
Have you seen the www.roarksformulas.com ? Check it out!
cheers,
gr2vessels
RE: Roark's (7th Ed.) Table 11.4, Case 2
Have a look at this site (provided by bridgebuster in another thread).
http:/
This will give you heaps of tables on various rectangular slabs, various support types, various loading conditions etc etc. It gives moments in each direction & support reactions (all in proportions of the span or support length).
These tables were originally developed (in the 1970's I think) using the method of finite differences. I believe the values have been verified by modern analysis methods with very good (& close) values.
Do a search on rectangular slabs (top of this page in this web site) for many types of queries on slabs, supports etc for info on previous threads.
RE: Roark's (7th Ed.) Table 11.4, Case 2
htt
Are they valid or not?
RE: Roark's (7th Ed.) Table 11.4, Case 2
prex
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RE: Roark's (7th Ed.) Table 11.4, Case 2
The data seems reasonable to me, i had a quick look through Timoshenko's plates and shells, and he (not surprisingly) covers the topic well. If you dont have the book, then if you let me know an email address (Rot13 etc) then i will copy and send the couple of pages that cover the derivations.