Need a book? Engineering books recommendations...

Return to index: [Subject] [Thread] [Date] [Author]

Re: Story Drift - Cracked or Uncracked Section Properties

[Subject Prev][Subject Next][Thread Prev][Thread Next]

Paul,

I believe you have to use cracked section properties in accordance with ACI 318-05 Sections 10.10 and 10.11.

Thomas Hunt, S.E.
Fluor



"Paul Blomberg" <paul.blomberg(--nospam--at)gmail.com>
06/06/2008 01:24 PM
Please respond to seaint
To
seaint <seaint(--nospam--at)seaint.org>
cc
Subject
Story Drift - Cracked or Uncracked Section Properties





We are checking some concrete moment frame calcs and debating internally about using the cracked or uncracked concrete section properties for the structural analysis.  There is some discussion that Cd (deflection amplification factor) incorporates the loss of stiffness as the concrete cracks while most believe that Cd increases the elastic deflections (using cracked section properties) to to account for inelastic behavior and that the elastic deflection is based on a cracked section.  The code is a mix of a north African national code with incorporation of ACI 318-05 and ASCE 7-05 just for fun.
 
So on this fine Friday, anyone want to chime in on this debate.  When do you use the uncracked section properties of concrete versus the cracked section properties?
 
Paul.
 
------------------------------------------------------------
The information transmitted is intended only for the person 
or entity to which it is addressed and may contain 
proprietary, business-confidential and/or privileged material.  
If you are not the intended recipient of this message you are 
hereby notified that any use, review, retransmission, dissemination, 
distribution, reproduction or any action taken in reliance upon 
this message is prohibited. If you received this in error, please 
contact the sender and delete the material from any computer.  

Any views expressed in this message are those of the individual 
sender and may not necessarily reflect the views of the company.  
------------------------------------------------------------