×
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!
  • Students Click Here

*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

Jobs

A book that covers the topic of Stiffness of thin-walled rectangular tubes under torsion loadings

A book that covers the topic of Stiffness of thin-walled rectangular tubes under torsion loadings

A book that covers the topic of Stiffness of thin-walled rectangular tubes under torsion loadings

(OP)
Hello All,

I would like to know if someone can give me a good reference of a book that covers the topic of torsion of thin-walled rectangular tubes from a stiffness perspective". I have a book with the theory for non-circular hollow-sections, but that's not really much.


Thanks,
Miguel Silva,MSc.

RE: A book that covers the topic of Stiffness of thin-walled rectangular tubes under torsion loadings

I don't have them to hand but I suspect one of Timoshenkos books is a good bet.

Be very careful, if you can check with FEA as well.

Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm?

RE: A book that covers the topic of Stiffness of thin-walled rectangular tubes under torsion loadings

Check in Roark's Formulas for Stress and Strain, and look up the references listed there.

RE: A book that covers the topic of Stiffness of thin-walled rectangular tubes under torsion loadings

Bruhn has a couple of chapters on this. Sorry, it's a terribly old book, and I doubt it will impress you, Miguel. But the aero engineers swear by it, and they are definitely concerned with thin-walled sections, of every shape, and equally concerned with their deflections, too. "Analysis and Design of Flight Vehicle Structures" by E.F. Bruhn, 1973, Jacobs Publishing.
Chapters A6 (Torsion) and A15 (Shear-flow in Closed Thin-walled sections).
Twist (radians per inch length of the member) is proportional to the torque divided by Shear Modulus and a constant. The constant is a shape factor determined by the cross-section.
Sometimes the shear stress can be estimated (if the section is simple enough) with just the enclosed area and the wall thickness.
Depending on the size and wall-thickness ratio, you may be concerned with wall buckling, and Bruhn has that, too.


STF

RE: A book that covers the topic of Stiffness of thin-walled rectangular tubes under torsion loadings

"The constant is a shape factor determined by the cross-section." Indeed, and that is the trick. Methods that have been used in the automotiv industry that I know of:

  1. enclosed area to mid section *wall thickness (shear flow assumption)
  2. membrane analogy
  3. thin plates in bending (doesn't work)
  4. FEA
  5. serious maths
  6. inscribed circle
If you start from a thin walled rectangular box, with equal thickness sides, then that has been well analysed. However, as you introduce asymmetries, variable wall thickness, and re-entrant shapes then the task gets harder. The inscribed circle method has a long history as a back of envelope method, for complex shapes like rockers and A pillars, and tends to be conservative but I think it has little to recommend it theoretically.

Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm?

RE: A book that covers the topic of Stiffness of thin-walled rectangular tubes under torsion loadings

(OP)
Hi all,

Thanks for all the replies,

"Depending on the size and wall-thickness ratio, you may be concerned with wall buckling, and Bruhn has that, too."

Sparweb, can you point the chapters where wall buckling is analyzed for torsion and for bending, if there is??

thanks,
Miguel Silva

RE: A book that covers the topic of Stiffness of thin-walled rectangular tubes under torsion loadings

"The middle".
The subject of buckling in every imaginable condition pervades most of the book.

STF

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!


Resources