How do you calculate response spectrum?
Understand that the method of determining response spectrum Sa=Sa(T) for a given diagram of accelerations F(t), where T refers to period, Sa refers to acceleration spectrum, t refers to time, while F(t) is a given time analysis function.
How do you create a response spectrum for earthquakes?
We generate earthquake design spectra by averaging spectra from past earthquakes to design structures to resist earthquakes. For very low periods, the spectral acceleration plot shows essentially a constant range above the ground acceleration line.
What is an earthquake response spectrum?
Earthquake response spectra 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 is spectral acceleration in earthquake?
PGA (peak acceleration) is what is experienced by a particle on the ground. SA (spectral acceleration) is approximately what is experienced by a building, as modeled by a particle on a massless vertical rod having the same natural period of vibration as the building.
Is response spectrum a dynamic analysis?
Response-spectrum analysis (RSA) is a linear-dynamic statistical analysis method which measures the contribution from each natural mode of vibration to indicate the likely maximum seismic response of an essentially elastic structure.
How do you find spectral response acceleration?
The spectral response acceleration, Sa, is calculated as follows: 1. For the interval 0 ≤ T < T0 (0 ≤ T < 0.12 s), Sa = SDS(0.4 + 0.6T/T0) Eq 11.4-5 Sa = 0.55g(0.4+0.6T/0.12) = (0.22 + 2.75T)g.
What is the purpose of response spectrum?
Response spectra are very useful tools of earthquake engineering for analyzing the performance of structures and equipment in earthquakes, since many behave principally as simple oscillators (also known as single degree of freedom systems).
Is response spectrum analysis static or dynamic?
linear-dynamic
Response-spectrum analysis (RSA) is a linear-dynamic statistical analysis method which measures the contribution from each natural mode of vibration to indicate the likely maximum seismic response of an essentially elastic structure.
What is SDS and SD1?
The parameters SDS and SD1 are used to calculate the design response spectrum in Section 11.4. 5 and the design base shear in Section 12.8.
What does SA 0.2 mean?
g. Median, 5% damped spectral acceleration (units = g; 1g ≈ 9.8 m/s2) Spectral acceleration for a period of 0.2 seconds at a probability of 2%/50 years for firm ground conditions (NBCC soil class C). Seismic hazard map # 1 (of 5)
What is the difference between equivalent static method and response spectrum method?
What is R factor? Equivalent Lateral Force (ELF) Analysis & Response Spectrum Analysis are types of linear elastic analysis but the difference is, one is static analysis while the other is dynamic analysis. ELF analysis is based on an assumption of static cantilever beam.
Why do we use response spectrum?
What is CT in seismic design?
Cs = seismic response coefficient determined in Section. 12.8.1.1 and 19.3.1 (dimensionless) CT = building period coefficient in Section 12.8.2.1. Cvx = vertical distribution factor as determined in Sec-
What does SD1 mean in seismic design?
SD1 = design, 5 percent damped, spectral response ac- celeration parameter at a period of 1 s as defined. in Section 11.4.4. SMS = the MCE, 5 percent damped, spectral response. acceleration at short periods adjusted for site class.
What is SS and S1 seismic values?
Ss: Spectral acceleration parameter at short periods corresponding to the mapped maximum considered earthquake. S1: Spectral acceleration parameter at a period of 1 sec corresponding to the mapped maximum considered earthquake.
What is PGA value?
Peak Ground Acceleration (PGA) is equal to the maximum ground acceleration that occurred during earthquake shaking at a location. PGA is equal to the amplitude of the largest absolute acceleration recorded on an accelerogram at a site during a particular earthquake.