TOPIC 4 Flashcards
Describes how a signal, wave, or sound loses strength or intensity as it passes
across a medium or space.
ATTENUATION
As seismic waves move away from the source of the earthquake, their amplitude
decreases.
SEISMIC ATTENUATION
The seismic wave’s intensity decreases with distance because the initial energy
generated is dispersed across a larger area.
GEOMETRICAL SPREADING
This is the energy loss due to anelastic processes or internal friction during wave
propagation also called intrinsic or anelastic attenuation.
ABSORPTION
Caused by the heterogeneity of the Earth’s crust and mantle and availability of
hydrocarbon reservoirs.
SCATTERING
The separating or decoupling of the structure from its foundation.
BASE ISOLATION
. Reduce the vibrations and oscillations of structures under dynamic loads.
DAMPING DEVICES
Process of strengthening existing structures to make them more resistance to
seismic forces.
RETROFITTING
The ratio of stored energy to the energy lost per cycle of oscillation.
QUALITY FACTOR
The speed or rhythm at which something tends to vibrate naturally when its
shaken or disturbed.
NATURAL FREQUENCY
TYPES OF DAMPING DEVICES
TUNED LIQUID DAMPERS
VISCOUS FLUID DAMPERS
TUNED MASS DAMPERS
TYPES OF VIBRATION
FREE VIBRATION
FORCED VIBRATION
Types of Forced Vibration
UNDAMPED FORCED VIBRATION
DAMPED FORCED VIBRATION
TYPES OF FREE VIBRATION
UNDAMPED FREE VIBRATION
DAMPED FREE VIBRATION
TYPES OF TRANSLATIONAL MOTION
MASS
DAMPER
SPRING
TYPES OF SCATTERING
RAYLEIGH SCATTERING
MIE SCATTERING
NON-SELECTIVE SCATERRING
PROBLEM SOLVING
0.2MM
0.173MM
0M
