Civil Engineering Reference
In-Depth Information
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Max. Top Lateral Displacement in x (mm)
Max. Top Lateral Displacement in y (mm)
Montenegro 1979_ Ulcinj2 #1
Montenegro 1979_ Ulcinj2 #2
Montenegro 1979_ Herceg Novi #1
Montenegro 1979_ Herceg Novi #2
Friuli 1976_Tolmezzo #1
Friuli 1976_Tolmezzo #2
Imperial Valley 1940_El Centro #1
Imperial Valley 1940_El Centro #2
Kalamata_Prefecture #1
Kalamata_Prefecture #2
Loma Prieta 1989_Capitola #1
Loma Prieta 1989_Cap tola #2
Imperial Valley 1979_Bonds Corner #1
Imperial Valley 1979_Bonds Corner #2
Static pushover_pos tive
Static pushover_negative
Figure 4.35
Incremental dynamic analysis for the irregular RC in Figure 4.2 (monitoring node@ C3):
x
- direction
(left
) and
y
- direction (
right
)
between the static pushover curve and maximum response points are mainly caused by structural
irregularities of the assessed system.
The use of IDAs for earthquake engineering applications has several advantages (Vamvatsikos and
Cornell, 2002). It provides a better understanding of the structural implications of rare ground- motion
levels, which are also discussed in Section 4.7. Moreover, the IDA allows a thorough understanding
of changes in the nature of the structural response as the intensity of the ground motion increases, e.g.
changes in peak deformation patterns with height, onset of stiffness and strength degradation, and their
patterns and magnitudes. It is also suitable to investigate the stability of all the above response features
with changes in the input motion.
4.6.2 Static Analysis
Static methods are generally used to assess the capacity or 'supply' of the structural system in terms
of actions and deformations at different limit states or performance objectives as those presented in
Section 4.7 .
Static analysis may be viewed as a special case of dynamic analysis when damping and inertia effects
are zero or negligible. The equation of static equilibrium for a lumped MDOF system can be derived
from equation (4.9.1) by setting inertia
F
I
and damping
F
D
forces equal to zero, leading to:
RFt
=
()
(4.27)
where
R
is the vector of restoring forces and
F
(
t
) the vector of the applied earthquake loads. The most
commonly used static analysis methods in earthquake engineering are outlined below. Static methods
can accommodate material inelasticity and geometric non-linearity. They, however, provide reliable
results only for regular structural systems such as those discussed in Appendix A .
