Deflection checks (Composite beams: EC4 Eurocode)
Tekla Structural Designer calculates relative deflections. (see: Deflection checks)
The following deflections are calculated for the loadcases specified in the construction stage load combination:
- Self weight - i.e. deflections due to self weight, excluding slabs
- Slab Wet - i.e. deflections due to loadcases of type 'Slab Wet'
- Dead - i.e. deflections due to loadcases of type 'Dead'
- Imposed - i.e. deflections due to loadcases of type 'Imposed' or 'Slab Wet'
- Total - i.e. deflections due to all loadcases included in the combination
Note:
In Eurocodes, the wet weight of the concrete is considered as if it was an imposed load due to its greater potential for variability during placing. Hence, its deflection is given on its own but also in conjunction with other imposed loads in the Construction Stage combination. It is advisable to create a 'construction stage imposed' loadcase to differentiate this from other imposed floor loads and include only this imposed loadcase in the Construction Stage combination, as in the example below.
The loads are taken as acting on the steel beam alone.
The “Service Factor” (default 1.0), specified against each loadcase in the construction stage combination is applied when calculating the above deflections.
If requested by the user, the total load deflection is compared with either a span-over limit or an absolute value The initial default limit is span/200.
Note: Adjustment to deflections. If
web openings have been defined, the calculated deflections are adjusted
accordingly. See: Web openings