×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Are you an
Engineering professional?
Join Eng-Tips Forums!
• Talk With Other Members
• Be Notified Of Responses
• Keyword Search
Favorite Forums
• Automated Signatures
• 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.

AS 4100 5.14.5

AS 4100 5.14.5

(OP)
Does anyone know if the d term of the equation given in 5.14.5 to refers to the beam depth or the critical flange width?

Furthermore, it seems counter-intuitive to me that as you increase the slenderness ratio of the stiffener, alpha-t approaches zero and therefore the requirement for the Is also approaches zero. I'm sure I'm mis-reading something but it is escaping me at the moment for sure.

RE: AS 4100 5.14.5

I would take "d" as the beam depth.

I agree that it seems counter-intuitive that as you increase the slenderness ratio of the stiffener Is approaches zero. However the slenderness will be limited by 5.14.2 and 5.14.3.

RE: AS 4100 5.14.5

(OP)

Agreed re: 5.14.2 and 5.14.3 - however, it also means in reverse that the chunkier your stiffener is, the larger Is needs to be.

RE: AS 4100 5.14.5

It does work out. For the requirement to become zero, you'd need an unstiffened web with about d/tw ~110. But that's partially restrained and the clause doesn't apply.

The (minus 0.6) complicates algebraic manipulation, but that part becomes a constant for a given beam and loading. Subtract it out and the remainder is what the stiffener has to deal with. *IF* we ignore the (minus 0.6) just to see the trend, could re-write Le as ~0.9*d, and Is = As*ry^2, and rearrange to get the gist.

Edit: Probably simpler to say that r_y is squared on the left side of the equation but less than linear on the right side, so it converges as the stiffener gets larger, and diverges if you make the stiffener smaller despite how the right-hand-side appears as written in the code.

RE: AS 4100 5.14.5

(OP)
Thanks steveh49 - I take your point.

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.

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:

• Talk To Other Members
• Notification Of Responses To Questions
• Favorite Forums One Click Access
• Keyword Search Of All Posts, And More...

Register now while it's still free!