Deflection Amplification Factor per ASCE 7-16 with ideCAD
How ideCAD defines the deflection amplification factor Cd according to ASCE 7-16?
The deflection amplification factor, Cd, is automatically obtained according to the structural systems selected from ASCE 7-16 Table 12.2-1.
Structural system selection, Response modification coefficient R, Deflection amplification factor Cd and Overstrength factor Ωo are defined by the user.
SYMBOLS
Cd = Deflection amplification factor
R = Response modification coefficient
Ie = Importance factor
δxe = Deflection
Over the past 30 years, research has shown that inelastic displacements can be significantly greater than ΔE for many structures and less than ΔE for others. As specified in Section 12.12 and Section 13 of ASCE 7-16, elevated deformations are used to evaluate story drifts and determine seismic demands on structural elements and non-structural components within structures not part of the seismic force-resistant system.
Fig. C12.1-1 shows the significance of seismic design parameters contained in the standard. The values of these parameters are provided in Table 12.2-1.
Structural System Type | Response Modification Coefficient, R | Overstrengh Factor, Ωo | Deflection Amplification Factor, Cd | Structural System Limitations Including Structural Height, hn (ft) Limits | ||||
---|---|---|---|---|---|---|---|---|
Seismic Design Category | ||||||||
B | C | D | E | F | ||||
A. Bearing Wall Systems | ||||||||
A1 - Special reinforced concrete shear walls | 5 | 21/2 | 5 | NL | NL | 160 | 160 | 100 |
A2 - Ordinary reinforced concrete shear walls | 4 | 21/2 | 4 | NL | NL | NP | NP | NP |
A3 - Detailed plain concrete shear walls | 2 | 21/2 | 2 | NL | NP | NP | NP | NP |
A4 - Ordinary plain concrete shear walls | 11/2 | 21/2 | 11/2 | NL | NP | NP | NP | NP |
B. Building Frame Systems | ||||||||
B1 - Steel eccentrically braced frames | 8 | 2 | 4 | NL | NL | 160 | 160 | 100 |
B2 - Steel special concentrically braced frames | 6 | 2 | 5 | NL | NL | 160 | 160 | 100 |
B3 - Steel ordinary concentrically braced frames | 31/4 | 2 | 31/4 | NL | NL | 35 | 35 | NP |
B4 - Special reinforced concrete shear walls | 6 | 21/2 | 5 | NL | NL | 160 | 160 | 100 |
B5 - Ordinary reinforced concrete shear walls | 5 | 21/2 | 41/2 | NL | NL | NP | NP | NP |
B6 - Detailed plain concrete shear walls | 2 | 21/2 | 2 | NL | NP | NP | NP | NP |
B7 - Ordinary plain concrete shear walls | 11/2 | 21/2 | 11/2 | NL | NP | NP | NP | NP |
C. Moment-Resisting Frame Systems | ||||||||
C1 - Steel special moment frames | 8 | 3 | 51/2 | NL | NL | NL | NL | NL |
C2 - Steel special truss moment frames | 7 | 3 | 51/2 | NL | NL | 160 | 100 | NP |
C3 - Steel intermediate moment frames | 41/2 | 3 | 4 | NL | NL | 35 | NP | NP |
C4 - Steel ordinary moment frames | 31/2 | 3 | 3 | NL | NL | NP | NP | NP |
C5 - Special reinforced concrete moment frames | 8 | 3 | 51/2 | NL | NL | NL | NL | NL |
C6 - Intermediate reinforced concrete moment frames | 5 | 3 | 41/2 | NL | NL | NP | NP | NP |
C7 - Ordinary reinforced concrete moment frames | 3 | 3 | 21/2 | NL | NP | NP | NP | NP |
D. Dual Systems with Special Moment Frames Capable of Resisting at Least 25% of Prescribed Seismic Foces | ||||||||
D1 - Steel eccentrically braced frames | 8 | 21/2 | 4 | NL | NL | NL | NL | NL |
D2 - Steel special concentrically braced frames | 7 | 21/2 | 51/2 | NL | NL | NL | NL | NL |
D3 - Special reinforced concrete shear walls | 7 | 21/2 | 51/2 | NL | NL | NL | NL | NL |
D4 - Ordinary reinforced concrete shear walls | 6 | 21/2 | 5 | NL | NL | NP | NP | NP |
E. Dual Systems with Intermediate Moment Frames Capable of Resisting at Least 25% of Prescribed Seismic Foces | ||||||||
E1 - Steel special concentrically braced frames | 6 | 21/2 | 5 | NL | NL | 35 | NP | NP |
E2 - Special reinforced concrete shear walls | 61/2 | 21/2 | 5 | NL | NL | 160 | 100 | 100 |
E8 - Ordinary reinforced concrete shear walls | 51/2 | 21/2 | 41/2 | NL | NL | NP | NP | NP |
F. Shear Wall-Frame Interactive System with Ordinary Reinforced Concrete Moment Frames And Ordinary Reinforced Concrete Shear Walls | ||||||||
F1 - Shear wall-frame interactive system | 41/2 | 21/2 | 4 | NL | NP | NP | NP | NP |
G. Cantilevered Column Systems Detailed to Conform to the Requirement for | ||||||||
G1 - Steel special cantilever column systems | 21/2 | 11/4 | 21/2 | 35 | 35 | 35 | 35 | 35 |
G2 - Steel ordinary cantilever column systems | 11/4 | 11/4 | 11/4 | 35 | 35 | NP | NP | NP |
G3 - Special reinforced concrete moment frames | 21/2 | 11/4 | 21/2 | 35 | 35 | 35 | 35 | 35 |
G4 - Intermediate reinforced concrete moment frames | 11/2 | 11/4 | 11/2 | 35 | 35 | NP | NP | NP |
G5 - Ordinary reinforced concrete moment frames | 1 | 11/4 | 1 | 35 | NP | NP | NP | NP |
H. Steel Systems not Specifically Detailed for Seismic Resistance, Excluding Cantilever Column Systems | ||||||||
H - Steel Systems not Specifically Detailed for Seismic Resistance | 3 | 3 | 3 | NL | NL | NP | NP | NP |
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