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P. Bratu et al.
combining the rheological elements, ensures the equivalent rigidities and equivalent
amortizations of the insulation system for the entire building.
The kinematic excitation of the seismic movement is represented by the instantaneous displacement of the first vibratory motion mode from the earthquake spectral
composition. Thus, the fundamental component, that is the first mode of movement,
is the spectral displacement x 0 = X 0 sin ωt or ˜
x 0 = X 0 e
jωt , where (ω, X 0 ) represents
the pulse and respectively, the amplitude of the first spectral mode with the period
T 0 =
2π
ω
[1, 2].
The dynamic response of the building is represented by the instantaneous displacement x = x(t) = A sin(ωt + ϕ 1 ) or ˜
x = ˜
Ae
jωt , where ˜
A = Ae
jϕ 1 . Also, the
instantaneous coordinate of the serial link point between the elastic element and
the viscous element, noted with B, is y = y(t) = B sin(ωt + ϕ 2 ) sau ˜
v = ˜
Be
jωt ,
where ˜
B = Be
jϕ 2 . The imaginary unit was denoted by j =
√
−1. Essentially, the
work highlights the dynamic response, the force transmitted by the earthquake to the
building through the dynamic insulation system, as well as the dissipate energy on
the viscous fluid amortization device [3, 4].
The paper highlights the possibility to model the dynamical isolation system of
the base using the Zener rheological schematics, for a building under a significant
seismic action for Romania, with ω = 4π rad/s or T 0 = 0.5 s and a corresponding
displacement X 0 = 0.3 m, on the fundamental excitation mode. The input data for
such an seism are adopted according the map containing the zones of high seismic
risk and the requirements of the Romanian Technical Regulation P 100/2004. For
the case under consideration, the favorable technical solution for a transmissibility
T = 0.05, or a dynamic isolation degree I = 95% is the adoption of the Zener
mode. This is achieved by appropriately associating the elastomeric antiseismic and
viscous fluid dissipation devices in combinations of favorable connections so that
the schematic can be a Zener equivalent model. For the case of study for a building in
Romania, based on the technical data mentioned above, in this paper are characteristic
the following parameters: the actual pulse of the mass on the horizontal axis ω n =
1.6 rad/s the excitation pulse for the fundamental mode of the seism ω = 4π rad/s,
equivalent damping ζ = ζ eq = 5% and relative pulse =
ω
ω n
= 7.8.
For the dynamic isolation calculation of the base it is used the fundamental mode of
excitation, according to the structural calculation regulations for constructions under
seismic action. Consequently, it is studied the dynamic response to fundamental
excitation, using linear viscoelastic modeling for the isolation systems of the base,
which can be modeled, in this way. The results are based on the researches and design
solutions developed by ICECON SA (Research Institute for Construction Equipment
and Technology from Bucharest, Romania) for some buildings in Romania that have
the basis isolated, that are confidential data.
P. Bratu et al.
combining the rheological elements, ensures the equivalent rigidities and equivalent
amortizations of the insulation system for the entire building.
The kinematic excitation of the seismic movement is represented by the instantaneous displacement of the first vibratory motion mode from the earthquake spectral
composition. Thus, the fundamental component, that is the first mode of movement,
is the spectral displacement x 0 = X 0 sin ωt or ˜
x 0 = X 0 e
jωt , where (ω, X 0 ) represents
the pulse and respectively, the amplitude of the first spectral mode with the period
T 0 =
2π
ω
[1, 2].
The dynamic response of the building is represented by the instantaneous displacement x = x(t) = A sin(ωt + ϕ 1 ) or ˜
x = ˜
Ae
jωt , where ˜
A = Ae
jϕ 1 . Also, the
instantaneous coordinate of the serial link point between the elastic element and
the viscous element, noted with B, is y = y(t) = B sin(ωt + ϕ 2 ) sau ˜
v = ˜
Be
jωt ,
where ˜
B = Be
jϕ 2 . The imaginary unit was denoted by j =
√
−1. Essentially, the
work highlights the dynamic response, the force transmitted by the earthquake to the
building through the dynamic insulation system, as well as the dissipate energy on
the viscous fluid amortization device [3, 4].
The paper highlights the possibility to model the dynamical isolation system of
the base using the Zener rheological schematics, for a building under a significant
seismic action for Romania, with ω = 4π rad/s or T 0 = 0.5 s and a corresponding
displacement X 0 = 0.3 m, on the fundamental excitation mode. The input data for
such an seism are adopted according the map containing the zones of high seismic
risk and the requirements of the Romanian Technical Regulation P 100/2004. For
the case under consideration, the favorable technical solution for a transmissibility
T = 0.05, or a dynamic isolation degree I = 95% is the adoption of the Zener
mode. This is achieved by appropriately associating the elastomeric antiseismic and
viscous fluid dissipation devices in combinations of favorable connections so that
the schematic can be a Zener equivalent model. For the case of study for a building in
Romania, based on the technical data mentioned above, in this paper are characteristic
the following parameters: the actual pulse of the mass on the horizontal axis ω n =
1.6 rad/s the excitation pulse for the fundamental mode of the seism ω = 4π rad/s,
equivalent damping ζ = ζ eq = 5% and relative pulse =
ω
ω n
= 7.8.
For the dynamic isolation calculation of the base it is used the fundamental mode of
excitation, according to the structural calculation regulations for constructions under
seismic action. Consequently, it is studied the dynamic response to fundamental
excitation, using linear viscoelastic modeling for the isolation systems of the base,
which can be modeled, in this way. The results are based on the researches and design
solutions developed by ICECON SA (Research Institute for Construction Equipment
and Technology from Bucharest, Romania) for some buildings in Romania that have
the basis isolated, that are confidential data.