AN INVESTIGATION OF DAMPING RATIO EFFECT ON EARTHQUAKE ENERGY INPUT

Year 2018, Volume: 1 Issue: 1, 8 - 18, 30.06.2018

Onur Merter , Taner Uçar

Abstract

Recent
earthquakes show that the strength and displacement-based methods in many
seismic design codes are not as reliable as the energy-based methods in seismic
design and evaluation of structures. The determination of earthquake energy
input to structures is the main concern for the energy-based structural design
methods. The seismic energy input to structures mainly depends on the strong
ground acceleration and the velocity time history of the structures. Current
studies about the seismic energy input show that the bases of researches are
established almost entirely for the single-degree-of-freedom (SDOF) systems.
This study investigates the variation of earthquake input energy of SDOF
systems which have different period and damping ratio values. Five real earthquake
records are selected to perform nonlinear time history analyses. SDOF systems
are assumed to be located on the same type of soil profile according to the
shear wave velocity values of the first thirty meters of the soil. Bilinear
hysteretic model is used and constant ductility is considered. Three different
damping ratios as three, five and ten per cent are taken. Energy time-histories
of bilinear SDOF systems are obtained graphically for selected earthquakes and
for different damping ratios. The main objective of the research is to see to
what extent the energy input has changed for different damping ratio values.

Keywords

Earthquake energy input, strong ground acceleration, single-degree-of-freedom system, damping ratio, energy input-time history

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