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





RE: Plywood over 3x T&G decking--Rigid or Flexible diaphragm
RE: Plywood over 3x T&G decking--Rigid or Flexible diaphragm
RE: Plywood over 3x T&G decking--Rigid or Flexible diaphragm
How would you estimate the deflection of the diaphragm in this case?
RE: Plywood over 3x T&G decking--Rigid or Flexible diaphragm
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
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
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
Mike Halloran
Pembroke Pines, FL, USA
RE: Plywood over 3x T&G decking--Rigid or Flexible diaphragm
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
Mike Halloran
Pembroke Pines, FL, USA