×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Shear Stress on Plate - Mystery Equation
2

Shear Stress on Plate - Mystery Equation

Shear Stress on Plate - Mystery Equation

(OP)

I am reviewing an already approved (not by me) hand calculated stress analysis of applied loads on an aluminum plate which has structural ribs on its underside. The plate was cut in half, exposing the structural ribs and the Max Moment, Max Torque and Max bending stress was found. The engineer then calculates the shear stress using the Max Torque found. The equation used looks familiar, but I am unable to find its origin anywhere in Roark's Stresses and Strains book.

It's the equation for Fs (see image) This looks so familiar, but I cannot find the original equation. Any ideas where I can find info in this equation? Thank you

RE: Shear Stress on Plate - Mystery Equation

Hi DustyK

Well it appears to be the J value for the torsional stiffness of the flat plate and the vertical ribs however I cannot find an identical example, if it were me I would politely ask the designer who did the original calculation to show me the reference he used.

“Do not worry about your problems with mathematics, I assure you mine are far greater.” Albert Einstein

RE: Shear Stress on Plate - Mystery Equation

I'd take a look in Bruhn, I think there's a similar/identical torsional shear stress equation there. Though it does look pretty standard anyway...

RE: Shear Stress on Plate - Mystery Equation

(OP)
Thanks for responding @DesertFox. Unfortunately, I do not have access to the engineer who wrote this. His reference was the Roark book, Case 30,Table X which does NOT exist, lol. BUUUUUUUUTTTTTT you put me on the right track. Here is the website I found, https://engineeringlibrary.org/reference/beam-tors... and I think this is it:


Seriously, thank you so much!

RE: Shear Stress on Plate - Mystery Equation

Hi DustyK

You’re welcome

“Do not worry about your problems with mathematics, I assure you mine are far greater.” Albert Einstein

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members! Already a Member? Login


Resources

Taking Control of Engineering Documents
This ebook covers tips for creating and managing workflows, security best practices and protection of intellectual property, Cloud vs. on-premise software solutions, CAD file management, compliance, and more. Download Now
The Great Project Profitability Debate
A/E firms have a great opportunity to lead the world into the future, but the industry’s greatest asset—real-time data—is sitting wasted in clunky, archaic ERP platforms. Learn how real-time, fully interactive dashboards in a modern ERP allow you to unlock data that will shape the future of the world. Download Now

Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close