×
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

AISC Double Angle Weld Capacity

AISC Double Angle Weld Capacity

AISC Double Angle Weld Capacity

(OP)
Hello, this is my first time posting on Eng-Tips, I hope you guys can help me out.

I have a question regarding the derivation of the weld capacity for double angle connections per AISC 13th edition page 10-11. I am trying to figure out where the 12.96 coefficient comes from. According to the book, the neutral axis is assumed to be (1/6)*L from the top of the angle, and the tops of the angles act in compression against each other.

If we call the vertical reaction R, then the form of the equation should be 0.928*D*L=sqrt(R^2+(R*e/a)^2) where "a" is the moment arm between the compression and tension resultants. Solving for R you get R=0.928*D*L/sqrt[1+(e^2/a^2)]. Back-solving to find "a" based on the 12.96 value, I have found that the moment arm should be (5/18)*L, but I can't come up with any distribution of loading that results in that moment arm. If the return is ignored and the load is triangularly distributed in both the tension and compression zones, I find that a=(2/3)*(L/6)+(2/3)*(5*L/6)=(2/3)*L. If the compression is a point reaction at the top of the weld and tension is a triangular distribution, a=(L/6)+(2/3)*(5*L/6)=(13/18)*L.

I hope that I'm on the right track and just missing something obvious.

Thanks in advance for any help!

RE: AISC Double Angle Weld Capacity

Blodgett's Design of Welded Structures has a derivation of this equation. Salmon and Johnson do as well.

RE: AISC Double Angle Weld Capacity

(OP)
Thank you! I had actually looked in Blodgett when starting to try and figure this out and must have skipped right over the chapter. Do you know where the assumption of an L/6 compressive bearing length comes from? It doesn't state in Blodgett or AISC, and I don't have access to Salmon and Johnson.

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