What is shock response spectrum used for?
The shock response spectrum is a useful tool for estimating the damage potential of a shock pulse, as well as for test level specification. Note that MIL-STD-1540C and MIL- STD-810E require this format for certain shock environments.
What is pseudovelocity?
What is Pseudo Velocity? Pseudo velocity is equal to the relative displacement SRS (difference between input and response) multiplied by each corresponding wn (2 * pi * natural frequency).
What is SRS shock testing?
Originally designed to evaluate structural responses to an earthquake, the SRS is a valuable tool for testing environments with complex transient shocks. Engineers use an SRS test to evaluate a device’s response to a transient event likely to occur in the end environment.
What is shock analysis?
Dynamic shock analysis measures the response of a system to a response spectrum. The load input is a base excitation with a response spectrum of either displacement, velocity, or acceleration. Dynamic shock analysis is not used for impulsive loads that vary with respect to time.
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 pseudo response spectrum?
It is used in building codes to represent the coefficient by which structural weight is multiplied to obtain the base shear. A is the peak pseudo-acceleration. A pseudo-acceleration response spectrum is a plot of A as functions of Tn. The parameters have certain characteristics that are of practical interest.
What is an SRS curve?
A Shock Response Spectrum (SRS) is a graphical representation of a shock, or any other transient acceleration input, in terms of how a Single Degree Of Freedom (SDOF) system (like a mass on a spring) would respond to that input.
What is an acceleration response spectrum?
The acceleration response spectrum of a ground motion is a relationship between the natural period of vibration of a sdof system and the maximum absolute acceleration that it experiences under the ground motion.
What do you mean by 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 the difference between PGA and SA?
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.
What is reponse spectrum method?
Response spectrum analysis is a method to estimate the structural response to short, nondeterministic, transient dynamic events. Examples of such events are earthquakes and shocks. Since the exact time history of the load is not known, it is difficult to perform a time-dependent analysis.
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)
How is PGA calculated?
PGA is calculated using attenuation function that describes the correlation between the local ground movement intensity the earthquake magnitude and the distance from the earthquake’s epicentre.
What is seismic response coefficient?
The R factor, or response modification coefficient, results from simplifying the seismic design process so that linear elastic, static analysis can be used for most building designs.