Time-Dependent Deflections (TS500)

Time dependent deflection calculation and control for beams are made automatically according to TS 500 13.2.3 .

Time dependent deflection calculation and control for slabs are made automatically according to TS 500 13.2.3 .

Deflection limits are determined by the user.

Notation

l_n= Span length of beam or one-way slab
δ_t = Total deflection
δ_i = Instantaneous deflection
δ_ig = Instantaneous deflection due to permanent loads
γ_t = Time-dependent favtor for sustained load
λ = Multiplier used for additional deflection due to long-term effects
ρ' = Compression reinforcement ratio

The total deflection, including the time dependent deflection can be obtained by using TS 500 Article 13.2.3.

The total deflection value is considered as the sum of the instantaneous deflection, δ_i and the deflection of permanent loads λδ_ig . The time dependent deflection calculation is shown in Equation 13.3 .

Multiplier used for additional deflection due to long-term effects λ is calculated according to Equation 13.4. In Equation 13.4 ρ' is compression reinforcement ratio and γ_t is considered as a Time-dependent favtor for sustained load.

Permanent deflection multiplier γ_t is taken as 2.0 based on 5 years or more loading time in accordance with Table 13.2.

Allowable maximum deflections for flexural members are given in TS500 Table 13.3.

Deflection limits can be adjusted in the Cracking / Deflection tab of the Beam Settings window .

The deflection limits conditions can be adjusted in the Deflection tab of the Tiling Settings window .

Deflection results can be examined in the Deflection & Crackings tab of the Beam Reinforcements window .

The results of Instantaneous deflection and time-dependent deflection of beams can be examined from the Beam Deflection and Crack Control report.

The results of Instantaneous deflection and time-dependent deflection of the slabs can be examined from the Slab Deflection Control report.