Ground Motions and Structures - Earthquake Engineering for Structural Design - page 315

Ground Motions and Structures 315

Stiffness Strength Ductility Robustness

Lateral
loads

Figure 8.17 Capacity curve and characteristics of the structural response
(Gioncu and Mazzolani, 2002)

Robustness . The attainment of maximum lateral load means the beginning of the
structure collapse. There are two collapse types, depending on the structural
robustness: brittle or ductile collapse. The main design target is to obtain a structure
with ductile collapse.
So, the s eismic performance of a structure should be evaluated based on the
nonlinear lateral load versus top displacement curve, which indicates its capacity to
resist lateral forces. Figure 8.17 presents the four principal stages of the structural
behavior: elastic, elastic-plastic, kinematic and collapse.
At the same time, this nonlinear capacity curve underlines the main attributes of