What is an earthquake spectrum?

The spectrum is a curve showing amplitude and phase as a function of frequency or period, or how much of each type of shaking there is from an earthquake.

What is meant by response spectrum?

Definition of a Response Spectrum. A response spectrum is a function of frequency or period, showing the peak response of a simple harmonic oscillator that is subjected to a transient event. The response spectrum is a function of the natural frequency of the oscillator and of its damping.

What is elastic response spectrum?

Now aseminal concept in earthquake engineering, the elastic response spectrum summarizes the peak response of all possible linear single-degree-of-freedom (SDF) systems to a particular com- ponent of ground motion.

What is earthquake response analysis?

Seismic analysis is a subset of structural analysis and is the calculation of the response of a building (or nonbuilding) structure to earthquakes. It later became clear that the dynamic properties of the structure affected the loads generated during an earthquake.

What is DVA spectrum?

Since these parameters are interconnected through the expressions (2.5 and 2.6) as given, all three parameters can also be represented in a single graph known as tripartite plot or Displacement velocity acceleration (DVA) spectrum. The intermediate portion is related to the maximum velocity of the ground motion.

What is the purpose of response spectrum?

4.2 Response Spectra Response spectra thus helps in obtaining the peak structural responses under linear range, which can be used for obtaining lateral forces developed in structure due to earthquake thus facilitates in earthquake-resistant design of structures.

What is the use of response spectrum analysis?

Response spectrum analysis can be used to estimate the peak response (displacement, stress, etc.) of a structure to a particular base motion or force. The method is only approximate, but it is often a useful, inexpensive method for preliminary design studies.

Why do we use response spectrum?

Response spectra thus helps in obtaining the peak structural responses under linear range, which can be used for obtaining lateral forces developed in structure due to earthquake thus facilitates in earthquake-resistant design of structures.

What is a design response spectrum?

A response spectrum is a jagged plot of peak response of all possible SDOF systems, and hence is a description of a particular ground motion. A design spectrum is smooth and is the envelope of the different elastic design spectra.

What are the earthquake parameters?

The critical parameters for the measurement of Richter magnitude are labelled, including the time interval between the arrival of the P- and S-waves — which is used to determine the distance from the earthquake to the seismic station, and the amplitude of the S waves — which is used to estimate the magnitude of the …

What is dynamic analysis in earthquake?

Dynamic analysis is conducted to obtain either a linear (elastic) or a nonlinear (inelastic) structural response. When elastic analysis is conducted, an empirical assessment of in- elastic response is made, since the design philosophy is based on nonlinear behaviour of buildings under strong earthquakes.

How are response spectra used in earthquake science?

A response spectrum is used to provide the most descriptive representation of the influence of a given earthquake on a structure or machine. 2. Structures subject to earthquake It is similar to a vehicle moving on the ground. In both cases there is relative movement between the vibrating system (structures or machines) and the ground.

When did Newmark and Hall develop the earthquake response spectrum?

In the 1982 EERI Monograph on “Earthquake Design and Spectra”, [2] Newmark and Hall describe how they developed an “idealized” seismic response spectrum based on a range of response spectra generated for available earthquake records.

How is the response spectrum used in structural design?

This was then further developed into a design response spectrum for use in structural design, and this basic form (with some modifications) is now the basis for structural design in seismic regions throughout the world (typically plotted against structural “period”, the inverse of frequency).

How is the ground response spectrum related to seismic damage?

As mentioned earlier, the ground response spectrum is the response plot done at the free surface of the earth. Significant seismic damage may occur if the building response is ‘in tune’ with components of the ground motion ( resonance ), which may be identified from the response spectrum.