Unformatted text preview: n equation of
motion for a single degree of
freedom system shown in the
figure, which consists of a
mass m, a spring K and an
input disturbance ue.
K and ue are called "Dynamic Impedance Function" and
"Foundation Input Motion".
You can understand easily the physical meaning of the
dynamic impedance function and the foundation input
motion. Second, we consider how to calculate the dynamic
impedance function and the foundation Input Motion.
Assuming a rigid
foundation before an
earthquake, that is:
When this system is subject to an unit lateral force, the
conditions of Eq.(9) are substituted into Eq.(1):
then, we obtain Eq.(10): note: the external force term becomes the unite.
(11) Comparing definition of the dynamic impedance function
K = K S + Kb (3) with Eq.(11):
We can understand that the inverse of displacement uf
coincides with the "Dynamic Impedance F...
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- Summer '14
- Inertia, Earthquake engineering, dynamic impedance, foundation input motion