Column web in shear
The resistance of unstiffened column web in shear is calculated using formula
Where the shear area is considered for rolled column as
The resistance is increased for web with horizontal stiffeners. The resistance increment is
but
Where is: | ds |
|
Mpl.fc.Rd |
| |
Mpl.st.Rd |
|
The resistance of column web in shear has to be greater than the average shear force in the column. This value is calculated using expression
Column web in shear
Shear stress induced by bending moment
The detail is converted into the analysis layout bending springs in bending.
The analysis model with springs
The unbalance of moments in the connection is added into account with the help of the transformation parameters β. The parameter β1 for the right connection is calculated using expression
The parameter β2 for the left connection is based on the following formula
The shear effect is added with the help of the reduction factor ω according to the table 6.3:
Transformation parameter β | Reduction factor ω |
0≤β≤0,5 | ω= 1,0 |
0,5<β<1,0 | ω= ω1+2(1-β)(1-ω1) |
β=1,0 | ω= ω1 |
1,0<β<2,0 | ω= ω1+(β-1)(ω2-ω1) |
β=2,0 | ω= ω2 |
Where the values of ω1 and ω2 are calculated using following formulas
Shear stiffeners
Supplementary web plates
Supplementary web plates increase the web resistance in shear, tension and compression. The plate width (maximum bs≤ 40εts without internal connection) should cover whole web height between roundings. The thickness should not be greater that the web thickness (ts≥ twc). The plate height Ls should cover complete effective web length in tension and compression. Welds should have sufficient effective thickness. For column web in shear and compression the value awe≥ ts/20,5 should be considered. The thickness awe≥ ts for longitudinal welds and awe≥ ts/20,5 for transverse welds should be used for column web in tension.
Column web with supplementary web plate
Stiffness
The stiffness of unstiffened column web in the shear is calculated using expression
Where is: | Avc |
|
β |
| |
z |
|