Damage Assessment of Inelastic Structures under Simulated Critical Earthquakes - Structural Seismic Design Optimization and Earthquake Engineering - page 144

Figure 10. Critical acceleration  x t

g ( ) for inelastic structure for case 1 (a) Time history (b) Fourier

amplitude spectrum

Figure 11. Critical acceleration  x t

g ( ) for inelastic structure for case 2 (a) Time history (b) Fourier

amplitude spectrum

and elastic-plastic force-deformation laws. The
application of the proposed method to more com-
plex structures and the use of more detailed
degradation models (e.g., trilinear degradation,
Takeda and Clough models) need to be investi-
gated. Additionally, in this paper Park and Ang
damage index has been used to assess the structure
performance. It may be emphasized that this dam-
age index has some limitations (Mehanny &
Deierlein, 2000, Bozorgenia & Bertero 2003).

This includes: (1) the weak cumulative component
for practical cases given the typical dominance
of the peak displacement term over the accumu-
lated energy term, (2) the use of a linear combina-
tion of deformation and energy in spite of the
obvious nonlinearity of the problem and the inter-
dependence of the two quantities, and (3) the lack
of considering the loading sequence effect in the
cumulative energy term. Furthermore, when E H
= 0 (elastic behavior), the value of DI PA should