Contact US

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

Analysing A Bolted Joint

Analysing A Bolted Joint

Analysing A Bolted Joint

I am required to analyse a bolted joint in order to find the most optimum bolt properties. i have done most of the calculations and what is left is just the flange stiffness. the formula i currently have is incorrect. can some one tell me what the formula for flange stiffness (Km) is?

RE: Analysing A Bolted Joint

The stiffness of a flange is related to the stiffness of the bolted joint. this means that Km is related to Kb. the formula can be located in any engineer's design handbook. the most common one is by Shigely. Just in case you cannot find it the formular for Km is given as

Km=dAE e(b(d/lm)

RE: Analysing A Bolted Joint

mmud9613:  Flange stiffness km, assuming compression zone frusta in bolt grip region, is computed as follows per Shigley, Mechanical Engineering Design, McGraw-Hill, 1989, p. 340, Eq. 8-13, where ki is stiffness of ith plate (layer) truncated frustum.

km = 1/summation(1/ki).

ki = pi Ei dhi tan(alpha)
   /ln[ (2 ti tan(alpha)   +   di  -  dhi)(di + dhi)
      /((2 ti tan(alpha)   +   di  +  dhi)(di - dhi)) ].

alpha = compression frustum apex half angle.
Ei = ith layer modulus of elasticity.
ti = ith layer thickness.
di = outer diameter of outer end of ith truncated frustum layer.
dhi = ith layer hole diameter.
pi = 3.141593.

RE: Analysing A Bolted Joint

shigley provides a pretty good formular but if you use this then you will have to use all of shigleys formulars otherwise solutions will vary. his way of doing things are right only if you use it from the begining.

RE: Analysing A Bolted Joint

Have you looked in "Roark's Formulas for Stress & Strain",published by McGraw-Hill?

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


Low-Volume Rapid Injection Molding With 3D Printed Molds
Learn methods and guidelines for using stereolithography (SLA) 3D printed molds in the injection molding process to lower costs and lead time. Discover how this hybrid manufacturing process enables on-demand mold fabrication to quickly produce small batches of thermoplastic parts. Download Now
Design for Additive Manufacturing (DfAM)
Examine how the principles of DfAM upend many of the long-standing rules around manufacturability - allowing engineers and designers to place a part’s function at the center of their design considerations. Download Now
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

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