Column web in tension and compression
Column web in tension
The design resistance of unstiffened column web is calculated using expression
where the factor ω corresponds to the shear impact, table is shown in the chapter "Column web in shear".
The effective height in tension for welded connections is given by the expression
where
for hot-rolled cross-sections and
for welded cross-sections.
Beam connection to hot-rolled and welded columns
The effective column web width beff,t for bolted connections is equal to the effective length of eqivalent T-stub.
Column web in compression
The design resistance of unstiffened column web is calculated using expression
where the factor ω corresponds to the shear impact, table is shown in the chapter "Column web in shear". The resistance is limited by its stability, that is taken into account with the help of the factor ρ.
The effective height in compression for welded connections is given by the expression
where
for hot-rolled cross-sections and
for welded cross-sections.
The effective column web height beff,wc for bolted connections with end plate thickness tp is calculated using expression .
The last part of previous expression (2tp) may be limited by the cantilever dimension. Following formula may be used for connections with angles on flanges
Where is: | ta |
|
ra |
|
Column web stability
The slenderness of column web 
is given by the formula
The web height of hot-rolled column dwc is given by the formula
The expression for welded columns:
The reduction factor ρ is given for
by the formula
and for
by the formula
Effect of axial stress in column
The axial stress may affect the resistance of column flange and web when calculating the compressive stresses. If the axial stress σcom,Ed at the beginning of root radius or weld edge of column flange is greater than 0,5fy,wc, The compressive resistance of column web Fc,wc,Rd is reduced by the factor kwc
Stiffness
The stiffness od unstiffened column web in compression k2 or stiffened or unstiffened column web in tension k3 is given by the formula
Where is: | beff,wc |
|
dwc |
| |
twc |
|
The value of beff,t,wc for bolted connection with one row may be considered as the minimum of effective lengths Leff (individually or as a part of bolt group).
Column web stiffeners
The column web may be stiffened both in tension and compression. The Stiffeners shall have the thickness equal to the beam flange thickness and identical or better steel grade. The full capacity of stiffeners may be reached also for partial stiffeners, if the stiffeners length is longer than (bb+ twc)/2, where bb is beam width and twc is the column web thickness.
Column web stiffeners