Stress checks (SLS) (Composite beams: EC4 Eurocode)
There is no requirement to check service stresses in EC4 for buildings (clause 7.2.2). However, since the deflection calculations are based on elastic analysis then at service loads it is logical to ensure that there is no plasticity at this load level.
Tekla Structural Designer calculates the worst stresses in the extreme fibers of the steel and the concrete at serviceability limit state for each load taking into account the proportion which is long term and that which is short term. These stresses are then summed algebraically. Factors of 1.00 are used on each loadcase in the design combination (you cannot amend these). The stress checks assume that full interaction exists between the steel and the concrete at serviceability state. The stresses are not reported unless the stress limit is exceeded, in which case a warning message is displayed.