Castellated beam's design (DG 31)

[DomDunk]

Dears,

I'm implementing a calculation program to design castellated beams according to Design Guide 31.

In chapter 3 the following limit states are listed:
1. compactness and local buckling
2. overall beam flexural strength
3. Vierendeel bending of tees
4. web post buckling
5. Axial tension / coompression
6. Horizontal shear
7. Vertical shear
8. Lateral-torsional buckling

I have this questions:
1. what section do I calculate these parameters?
2. I imagine that it refers to Mp of the section (the buckling is evaluated in item 8). Mp of which section? net or gross section?
3. OK
4. OK
5. From which section? I apply sections D or E of the AISC 360-16? Net or gross section?
6. OK
7. OK
8. OK (I imagine that complements the limit state 2, overall beam flexural strength)

Do you have a bibliography that could help me clarify that design procedure?

Thanks,

Daniel

 

[robyengIT]

Google : "castellated beam Arcelor" (available a software too. If i remember well the software is called "Angelina")

 

[robyengIT]

and furthermore a technical research from Europe

 

[robyengIT]

and another one from Tata steel according to Eurocode

 

[SethGuthrie]

Ram Steel or the single beam program, Ram SBeam, can also be used for C-Beams.

 

[Agent666]

Some answers for some of the q's. If you read the rest of chapter 3 and the design examples as I'm sure it goes through and answers most of your questions, post back if there is anything thats not clear. I'd second a recommendation to read through the SCI P355 design guide robyengIT linked to as well, as its a great resource. The AISC guide borrowed heavily from the established UK practices I believe.

1. usually you are calculating the section properties for the remaining top and bottom tee sections when they are under compression (either global axial load or axial compression induced by flexure). Just follow the same procedures you might follow to work out the effective section properties for any normal steel member (usually using b/t slenderness ratios).

2. Obviously the net section will govern at the web holes, and the gross section at the full section. Obviously gross section might also be reduced by holes in the flanges, usually codes allow these to be ignored until they reach a certain percentage of holes which is the transition between gross (based on A_gross * Fy) and net section failure criteria (based on A_net x Fu).