Shear lag in quasi-channel section

[JeanLucPicard]

Hi all,

I have a thin-walled i.e. cold-formed quasi-channel section (pic below). Of course it has principal axis are not aligned with central axis. Using EN1993-1-3 & EN1993-1-5 I've calculated that I have to include shear lag i both flanges (? is it for both ?), my bending moments around principal axis are all over the place. Which bending moment should I take into account when calculating β factors? When I calculate effective width b[sub]eff[/sub] should i discard the upper stiffener... ?

Thank you in advance,
any advice is helpful
Jean-Luc

Live long and prosper!

 

[MotorCity]

I am not familiar with the code you mentioned, but in AISC shear lag is typically not considered in flexural members. Shear lag is for members loaded in tension. Why do you believe you need to consider shear lag?

 

[JeanLucPicard]

@ MotorCity, thank 4 the reply. EN1993-1-3 says that while in bending a shear lag (SL) should be inculded if it's applicable and points out to the code EN1993-1-5 for the calculations. There I don't satisfy the the requirement thus I must include SL.

As I get it, the SL is for normal stress, not so much is it tension or not? Howerver, you are right as I saw few examples only taking the tension members. On the other hand, composite structure, RC plate + Steel I beam takes SL into effect in compression in RC plate.

I've calculated and reduced both flanges, however, I'm not certain in it.


Live long and prosper!

 

[canwesteng]

What is shear lag as defined in EN1993? I'm getting awfully confused

 

[JeanLucPicard]

@Canwesteng

I'm not sure what is the issue, so I assume that EN1993 is. EN1993 are European provisions (Eurocode) for steel design

Live long and prosper!