Table C-5 Elastic Response to Reference 1.0g NUREG/CR-0098 Spectrum (7% damping) - Continued

DOE-STD-1020-2002

= 4.1 to 5.6

(C-14)

However, a more accurate estimate of may be obtained from Equation C-8 after

estimating the inelastic deformed shape. A slightly conservative estimate of the inelastic

deformed shape may be obtained by assuming that all of the nonlinear drift occurs in the story

with the lowest ratio of the capability to the demand (the first story for this example). The other

stories retain the same differential drifts as given by δQ in Table C-8. Thus:

= 1.06 inch

= 1.12 inch

= 1.22 inch

and from Equation C-8:

= 4.6

(C-15)

Computation of Inelastic Energy Absorption Factor - For concrete shear wall structures,

it is recommended that the inelastic energy absorption factor F be computed by the effective

frequency/effective damping approach of Reference C-24, as summarized herein. For this

example, it will be assumed that the force-deflection relationship on initial loading is

elasto-perfectly plastic with an ultimate capacity Vu. Thus, the ratio of secant to elastic

frequency is given by:

(C-16)

Then, the effective frequency is given by:

C-38