×
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

Truss Plate Moment Capacity

Truss Plate Moment Capacity

Truss Plate Moment Capacity

(OP)
It would be great if somebody could point me in the direction of any documents related to estimating the in-plane moment capacity of metal truss plates for wooden roof structures. I was hoping that I could find a method of quickly, and relatively accurately, assessing the moment capacity of the contact areas for each member at a joint.

I am researching wind effects on residential structures and need rough capacities to identify the locations of probable failure initiation.

RE: Truss Plate Moment Capacity

Good info here: Link

I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.

RE: Truss Plate Moment Capacity

(OP)
Thanks Koot!

I have been attempting to pick apart the Ma equation from the TPI Clause 8.7.1, but find it to be quite complicated. In the TPI 2007 Commentary I also found reference to the moment provisions from the previous version, where the applied moment was converted into an equivalent tensile force and compared to the tensile capacity of the joint.

Given that many of my modeled material properties are assumed according to our assessment of "typical" house construction, and that much of my analysis has been approximate to this point (working through an analytical "proof of concept" rather than a detailed assessment) I'm wondering if its worth my limited time to dive into the current provision or settle for a range of approximate values.

Any thoughts?

RE: Truss Plate Moment Capacity

Why are you trying to develop moments in a wood truss with common truss plates? Simplify.

RE: Truss Plate Moment Capacity

(OP)
I plan on analyzing the roof model using both pinned and rigid (separate cases) connection assumptions in hopes to get an envelope of the highest possible member end (joint) forces. Now I'm looking for capacity estimates to compare the extreme end moments and axial forces to, so that we can get a rough idea of the roof pressures/wind speeds & directions required to cause failure at each chord joint.

I also intend to neglect load and resistance factors to compare (estimated) true capacity to expected wind loads.

RE: Truss Plate Moment Capacity

While I find the alternate method much more appealing to my intuition, I'd be inclined to go with the newer method. I can't see it taking more than 30 min to sort out. Especially if you're just going to be coding it into a spreadsheet anyhow. I doubt that either method is particularly accurate.

I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.

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