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

Longeron splice connection

Longeron splice connection

Longeron splice connection

Hi all

I have a longeron which is going to splitted and joined together with bolts like in the picture below.

i extracted the forces from gfem model. I have Fx, Fy, Fz and Mx, My, Mz.

My question is , how should i distrubute forces on bolts?

I think the forces along x direction acting as shear forces on the web and shear forces on the cap.

the forces alond z direction acting as shear forces on the web and tension forces on the caps.

the forces along y direction acting as shear forces on the cap and tension forces on the web.

MX acting shear on the cap and tension on web.

MY action shear on both web and caps.

MZ acting shear on caps and tension on web

Do you think my way correct?

RE: Longeron splice connection

ok, primary load Fz ... apply to the two web fasteners, react on the other side of the split. Remember there is now a couple ... if you like the Fz load at the split is being carried by the two web rivets "d" inches away from the split, so there's an Fx couple ... Fx*h (distance between web rivets) = Fz*d ... yes? clear as mud ?
next primary load Fx ... apply over all 6 rivets, or 4 cap rivets, or 2 web rivets !!??
Next primary load, Mz ... this is a couple between the inner and outer finger splices. The splice is H inches high (between the finger straps), then load into caps is Mz/H over 2 rivets.
Fy, Mx and My should be small, and out-of-plane ... neglect or apply to skin rivets.

But better is to look up how your company wants you to analyze splices (rather than listening to some guy on the internet).

another day in paradise, or is paradise one day closer ?

RE: Longeron splice connection

That's a poor way to splice a longeron. The splices cannot transfer shear loads between each other. I definitely would never do that, and never have. Use angles or something other than just plates.

RE: Longeron splice connection

Some feedback on your assumption: "... as shear forces on the web and tension forces on the caps."
If you were to compare the relative stiffness of those two loadpaths (in-plane shear vs out-of-plane tension) you'd find those joints to be an order of magnitude (or more) softer out-of-plane, compared to in-plane. Hence why fastener tensile loading is often considered neglible when idealising structures.
In summary, think about relative stiffneses. Loads follow the stiffest loadpath. So you shouldn't expect any significant load to be carried by fastener tension when there's an adequate shear connection available.

RE: Longeron splice connection

Hi all

Thanks for all answers. As far as i understand from your answer.

I have to solve the problem with in plane loads.All the fasteners should carry the shear loads. Am i right?

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


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