×
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

RIDIG DIAPHRAGM CHORD SLIP NEEDED

RIDIG DIAPHRAGM CHORD SLIP NEEDED

RIDIG DIAPHRAGM CHORD SLIP NEEDED

(OP)
I am doing an analysis of a wood-framed rigid diaphragm and I am trying to find the chord anchorage slip of various holdowns and straps.  The Simpson Company supplies some but not all of their holdown and strap values.  Does anyone know a source for these values?  Do you engineering each strap or holdown for slip by the mechanics of the material?  Do you use a standard value, say 1/8" or 1/16" for the slip on these holdowns or straps?  Thank you.

RE: RIDIG DIAPHRAGM CHORD SLIP NEEDED

An engineer's perspective:

I specify Simpson products quite often. Values shown in the catalog should imitate those shown in the ICBO ER report, etc. As far as I understand it, these values are based upon tests done in a lab somewhere using a test jig that complies with standards accepted by the building code.

Slip would depend upon what type of anchor is used. Holdowns with bolts into the wood member would have slippage due to the standard 1/16" oversize of the bolt holes in the wood member. The Simpson PHD holdown uses lag screws which should eliminate this problem. The Simpson PHD also eliminates the other major concern, that of internal distortion of the holdown itself. PHD stands for "pre-deflected holdown."

Slip should be defined as translation of the hardware to the point where the hardware fully engages the fasteners.

Keep in mind that shrinkage of the wood member due to the escape of water content over a long period of time can serve to take up a significant portion of the "slack" in the assembly.

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