Shear capacity according to eurocode , when to use which equation

[bojoka4052]

I am looking at eurocode to calculate shear capacity, and under section "6.2.6 Shear", there are two different shear checks:

Eq 6.18

Eq 6.19

When there is no torsion we can use equation 6.18?

But if we do have torsion we have to use eq 6.19? - but I am not sure what buckling verification in section 5 of EN 1993-1-5 theyre referring to, but will I have to do all the checks in section 5?

Link to EN 1993-1-5:

https://www.phd.eng.br/wp-content/uploads/2015/12/en.1993.1.5.2006.pdf

 

[HTURKAK]

DEAR bojoka4052 ;

Link to EN 1993-1-5 Part 1-5 is for Plated structural elements and the shear capacity defined under section "6.2.6 Shear" is at EN 1993-1-1 Part 1-1: General rules and rules for buildings .

I will try to reply your questions ;


A= Yes but for plastic design . Plastic shear resistance is given with formula (6.18) . ( The shear yield stress of steel is approximately ( 1/√3 )of tension yield stress. You may look (6.18.3) for ( Av ) the shear area.


A= NO!!!! The formula 6.19 and clause 6.2.6(4) is for checking the elastic shear resistance of the section and the shear stresses are calculated assuming elastic material properties . This check is normally applied to unusual sections or in cases where plasticity is to be avoided, such as when repeated load reversal occurs etc.

If you do have torsion , you should look ( 6.2.7 Torsion ) and you have to use the formulas (6.25,26,27,28). Vpl,Rd is the design plastic shear resistance and obtained from clause 6.2.6.

 

[centondollar]

You write "When there is no torsion we can use equation 6.18?".

I don't want to be obtuse, but does the equation in question mention torsion? No. It mentions elastic resistance and notes that the equation does not apply if the shear buckling (EN 1993-1-5) of the web is the governing failure mode.

If you do not want to think about what you find in the code equations, you could at least try to use "control-F" and type in "torsion" to find what HTURKAK all too generously provided you.

PS. If your question relates to real design, someone in your office should be able to explain this to you. Asking questions about trivial matters online does not inspire confidence in your company and the designs its employees produces.