The deflection amplification factor, Cd, is automatically obtained according to the structural systems selected from ASCE 7-16 Table 12.2-1.


Cd = Deflection amplification factor
R = Response modification coefficient
Ie = Importance factor
δxe = Deflection

Research over the past 30 years 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 that are 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, provided in Table 12.2-1.