Contact US

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!

*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

AS3600-2018 Shear: Calculating 'A_ct'

AS3600-2018 Shear: Calculating 'A_ct'

AS3600-2018 Shear: Calculating 'A_ct'

Hi all,

Clause of the new AS3600 provides us with an option to calculate 'A_ct' if the strain at 'mid-depth' is less than zero. However, the term 'mid-depth' is never clarified in the code. Based on my cursory reading of the FIB 2010 model code - which also uses MCFT, it appears that mid-depth should really be the middle of the depth between centroids of tension and compression chords (and not the section depth). This would imply that the engineer should iterate to find the elastic neutral axis under the applied loads, calculate the centroids of tension and compression and then finally calculate A_ct. On the other hand, the code does use the words 'mid-depth of the section' but using half the depth of the section doesn't seem mathematically correct

Am I overthinking this ? Or is the code in the wrong here ?

RE: AS3600-2018 Shear: Calculating 'A_ct'

The calculation of Act is intended to be an approximation to avoid the need for a cracked section analysis. The Canadian codes simply defines it as the area of concrete on the flexural tension side of the member (as in AS3600-2018). FIB is referring to the middle of the effective shear depth. Either way it would be about the same.

RE: AS3600-2018 Shear: Calculating 'A_ct'

You are over thinking it.

There are several areas of the calculation where the "tension half" of the section are referred to. They are based on D / 2. Similar to the Canadian Code.

RE: AS3600-2018 Shear: Calculating 'A_ct'

This is using Act in Eq You can just take εx = 0. Is that satisfactory?

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! Already a Member? Login


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