Roarks Formulas

[dmccarthy]

In the Fourth Edition of Roark's "Formulas for Stress and Strain" on page 176 the book gives Loading Case 19 (Ring Symmetrically Supported and Loaded by it's own weight of w lb. per linear inch).
This Load Case is omitted from later editions of this book. Does anyone know why?
This formula would be very useful to me for the design of duct saddles. However, I'm concerned that there may have been an error in it and that is why it was omitted.

Thank you

dmccarthy

 

[meca]

I don't know why Case 19 was dropped in the 6th edition, I have wondered the same thing. It is a very useful loading scenario, and I have continued to use it. I have found all of these ring calculations to be very conservative, so it is beyond me why this was ommitted. I sell a ring program at

http://www.mecaconsulting.com,

which is based upon Roark's 6th edition. Because the 6th edition ommitted Case 19 and a couple of others I liked to use, I went ahead and included these in my program.