NIEUWE BLIK OP KIP EN KNIK - Bouwen met Staal

H 1a Summary
F
M = v
22
z 2
Ez
k3
2
in which the factor k 3 depends on the combination of beam-column type and load case.
Check of stability, strength and stiffness
The safety in the ULS (Ultimate Limit State; UGT in Dutch) is evaluated by checking if the
requirements are met. After superposing all influences (accounting for the flexural strength
and compression strength) a unity check is made:
F M M
+ + ≤
F M M
c y1
z1
1
u yu zu
Herein the stability has been accounted for 'automatically'. In cantilever beams the maximum
moments in both directions usually do not occur at the same cross-section so there may still
be a small reduction. If (in rare cases) a load acts in the 'weak' direction and/or the 2 nd order
displacement in the 'strong' direction is not negligible, the relevant components may simply
be added to the unity check.
Chapter 8 describes how n z* can be applied to calculate the displacement in the SLS
(Serviceability Limite State; BGT in Dutch). The total displacement is calculated by:
n
v = v
n
*
z
*
z −1
0
The requirement in SLS is:
v ≤ vpermissible
A distinction can be made here between the total displacement and the additional
displacement that occurs after the structure is subjected to its permanent or dead load.
Design codes reduced to a common denominator
In Chapter 9 the application of this method is compared with the rules in some current design
codes for timber, steel and concrete. Because of the high degree of agreement, the results of
the comparison offer particularly interesting possibilities for practical application.