Calculation of Time-Dependent Deflections per ACI 318-19 with ideCAD

How does ideCAD calculate time-dependent deflections according to ACI 318-19?

• Time-Dependent Deflection is calculated automatically.

Notation

A_s' = area of the compression reinforcement, in²
b = width of compression face of member, in.
d = distance from extreme compression fiber to centroid of longitudinal tension reinforcement, in.
ρ' = ratio of A_s' to bd
ξ = time-dependent factor for sustained load
λ_Δ = multiplier used for additional deflection due to long-term effects

According to ACI 24.2.4.1.1, additional time-dependent deflection resulting from creep and shrinkage of flexural members can be calculated as the product of immediate deflection caused by sustained load and the factor λ_Δ.

ρ' is the ratio of the A_s' , area of the compression reinforcement, to bd

Time-dependent factor ξ is 2.0 in accordance with ACI Table 24.2.4.1.3

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AISC 360-16 and AISC 341-16 Steel Design

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• Maximum Permissible Calculated Deflections per ACI 318-19 with ideCAD

• Calculation of Immediate Deflections per ACI 318-19 with ideCAD