×
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

Plywood over 3x T&G decking--Rigid or Flexible diaphragm

Plywood over 3x T&G decking--Rigid or Flexible diaphragm

Plywood over 3x T&G decking--Rigid or Flexible diaphragm

(OP)
Would you consider a diaphragm constructed with plywood over 3x T&G decking to be rigid or flexible? Any references would be appreciated! Thanks in advance.

Nancy H. Devine, P.E., S.E.

RE: Plywood over 3x T&G decking--Rigid or Flexible diaphragm

A lot of that would depend on the aspect ratio in my eyes.

RE: Plywood over 3x T&G decking--Rigid or Flexible diaphragm

And on the deflection of the diaphragm relative to its supports

RE: Plywood over 3x T&G decking--Rigid or Flexible diaphragm

(OP)
The building is basically square.

How would you estimate the deflection of the diaphragm in this case?

RE: Plywood over 3x T&G decking--Rigid or Flexible diaphragm

Assuming a USA project (you might specify which country you are in)....

The IBC has equations for estimating diaphragm stiffnesses and both the IBC and ASCE 7 have definitions of rigid vs. flexible diaphragms that depend on the building size, aspect ratio, etc. - diaphragm deflection vs. shear wall deflections (per MotorCity's comment).

The trick in your case is that you also have a T&G decking under it which certainly adds to the diaphragm stiffness above and beyond the plywood by itself.

There have been posts here on E-T that mentioned new information on T&G decking shear capacities and stiffness - do a search.

You might then have to estimate each and combine into one overall shear stiffness (G') and then see how your diaphragm rates vs. the shear wall deflections.

Check out Eng-Tips Forum's Policies here:
FAQ731-376: Eng-Tips.com Forum Policies

RE: Plywood over 3x T&G decking--Rigid or Flexible diaphragm

Boat hulls might have 3 plies of T&G.
Why would a building have that many plies?

Mike Halloran
Pembroke Pines, FL, USA

RE: Plywood over 3x T&G decking--Rigid or Flexible diaphragm

Mike - it may be 3" thick T&G, not 3 plies.

Check out Eng-Tips Forum's Policies here:
FAQ731-376: Eng-Tips.com Forum Policies

RE: Plywood over 3x T&G decking--Rigid or Flexible diaphragm

Please forgive me if I am more confused than usual.

Mike Halloran
Pembroke Pines, FL, USA

RE: Plywood over 3x T&G decking--Rigid or Flexible diaphragm

Or a 3 lam T&G product where instead of routing out the tongue and groove it is manufactured with three lams offset to form a tongue and groove.

Check out Eng-Tips Forum's Policies here:
FAQ731-376: Eng-Tips.com Forum Policies

RE: Plywood over 3x T&G decking--Rigid or Flexible diaphragm

I was thinking that if I found 3 plies of T&G in a building, I would suspect that two are rotted.

Mike Halloran
Pembroke Pines, FL, USA

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

White Paper: Industrial Control Basics: Contactors
A contactor is an electrical device used for switching an electrical circuit on or off. Considered to be a special type of relay, contactors are used in applications with higher current carrying capacity, while relays are used for lower current applications. Download Now
Research Report: State of IoT Adoption in Product Development 2019
This research report, based on a survey of 234 product development professionals, examines the current state of Internet of Things (IoT) adoption by product design teams, its perceived importance, and what features and capabilities teams consider important when making decision about adding IoT functionality to their products. Download Now
Research Report: Augmented Reality for Maintenance, Repair and Overhaul (MRO)
The term Industry 4.0 denotes a cluster of technologies that’s poised to fundamentally reshape manufacturing and bring about a new industrial revolution. These include 3D printing (AM), the Industrial Internet of Things (IIoT), artificial intelligence (AI) and mixed reality technologies, more commonly known as virtual reality (VR) and augmented reality (AR). Download Now

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