×
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

Multi-row bolted lap joint calculations
6

Multi-row bolted lap joint calculations

Multi-row bolted lap joint calculations

(OP)
How do I calculate the UTS of a multi-row bolted lap joint like this?


Anything I find in PDF involves someone's thesis (a bit over my head) or only involves one bolt (not much help).
Can someone point me to something in the middle for the case shown?

Thanks

RE: Multi-row bolted lap joint calculations

(OP)
Thanks desertfox. That covers the basic issues but not how to allow for multiple rows of bolts/rivets. You see in my drawing that the two rows of bolts have different numbers of bolts and also they are staggered.

I have a feeling that that will complicate the issue, but it is a common occurrence in industry. I need to know how to make those allowances.

Cheers

RE: Multi-row bolted lap joint calculations

Hi vagulus

The rivet joints shown on that link show multi rows of rivets with varying numbers of rivets/bolts and I can't see the difference between your example and theirs, what am I missing?

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

RE: Multi-row bolted lap joint calculations

(OP)
Thanks CoryPad

FTR: For NASA RP-1228 Fastener Design Manual by Richard Barrett use this link. I couldn't get the one you posted.

Thanks again

RE: Multi-row bolted lap joint calculations

2
Vagulus:
You might want to dig out your old Strength of Materials or Machine Design text books, assuming you didn’t sell them used, for a six-pack. Good texts will have something on bolted connections. Also, any of the Structural, and specifically structural steel codes, will have info on bolted joints; spacing, edge distances, spacing btwn. rows, etc. And, they will also have info and methods for analyzing net sections around the various bolt patterns to determine the critical load path for a given bolt pattern. Right now, in your sketches and with their proportions, it looks like your bolt size, spacings and edge distances are much to tight for a practical joint. And, in a more detailed analysis of a bolted joint, you should give some thought to the fact that all the bolts don’t come into play at once. Some of them must be in bearing and starting to yield in bearing before others really come into play. There are also issues of how tightly you fix (tighten) the bolts.

RE: Multi-row bolted lap joint calculations

(OP)
Ah Ha! dhengr

You are right on the money with the things I am trying to address. Sadly, I am just a beginner in this game, and it is not a case of digging out old Strength of Materials or Machine Design text books as a case of digging them up.

You wrote of: ... your bolt size, spacings and edge distances are much to tight for a practical joint. And, in a more detailed analysis of a bolted joint, you should give some thought to the fact that all the bolts don’t come into play at once. Some of them must be in bearing and starting to yield in bearing before others really come into play.

This is the heart of my enquiry. Would you be good enough to suggest some old text books which deal with these issues? It appears that modern textbooks have other issues at heart.

Thanks

----------------------------------------
Artificial Intelligence is no match for Natural Stupidity

RE: Multi-row bolted lap joint calculations

Unless I'm missing something, all of your concerns should be addressed in the AISC specification (structural steel code): https://www.aisc.org/WorkArea/showcontent.aspx?id=...

You'll be most interested in sections J3 (related to bolt capacity, spacing, edge distances, etc), J4 (for capacity of connected elements, your plates) and B3 (which defines gross and net areas -- this will address your staggered holes concern). The commentary portion in the latter half of the document may also be useful.

Regarding dhengr's point about bolts coming into play at different times -- for a typical bolted connection with standard size holes (1/16" larger than nominal bolt diameter), we typically assume that structural grade steel bolts can yield and act in a ductile fashion until all the bolts in the connection are engaged -- regardless of the initial fit-up "scatter". Of course, if you have oversized holes (for example, in a foundation anchor bolt application), this assumption requires further consideration.

RE: Multi-row bolted lap joint calculations

(OP)
Thanks, Lomarandil, that's the beast! Now to find the Australian Standard equivalent for this metric world I live in.

Thanks again

----------------------------------------
Artificial Intelligence is no match for Natural Stupidity

RE: Multi-row bolted lap joint calculations

In an Australian context the equivalent design information is contained in the Australian Steel Code AS4100 in the connections chapter.

RE: Multi-row bolted lap joint calculations

(OP)
Thank you Agent666

----------------------------------------
Artificial Intelligence is no match for Natural Stupidity

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