# IEEE 344-2004 pdf free

**IEEE 344**-2004 pdf free.IEEE Recommended Practice for Seismic Qualification of Class 1 E Equipment for Nuclear Power Generating Stations.

For the purpose of this recommended practice, thc following terms and conditions apply. IEEE tOO, The Authoritative Dictionary of IEEE Standards Terms. Seventh Edition LB lJ, should be referenced for terms not defined in this clause.

3.1 broadband response spectrum: A response spectrum that describes motion in which amplified response occurs over a wide (broad) range of frequencies.

3.2 coherence function: A comparacise relationship between two time histories. It provides a statistical estimate of how much two motions are related, as a function of frequency. The numerical range is from zero for unrelated, to + 1.0 for related motions.

3.3 correlation coefficient function: A comparative relationship between two time histories, It provides a statistical estimate of how much Iwo motions are related, as a function of time delay. The numerical range is from zero for unrelated, to +1.0 for related motions.

3.4 critical seismic characteristics: Those design, material, and performance characteristics of an equipment item that provide as. .uraice that the item will perform its required function under seismic loads.

3.5 cutoff frequency: The frequency in the response spectrum where the ZPA asymptote begins, This is the frequency beyond which the single-degree-of-freedom (SDOF) oscillators exhibit no amplification of motion and indicate the upper limit of the frequency content of the waveform being analyzed.

3.6 damping: An energy dissipation mechanism that reduces the amplification and broadens the vibratory response in the region of resonance. It is usually expressed as a percentage of critical damping. Critical damping is defined as the least amount of viscous damping that causes a SDOF system to return to its original position without oscillation after initial disturbance.

3.7 earthquake experience spectrum (FFS): The response spectrum that defines the seismic capacity of a reference equipment class ha.sed on earthquake experience data.

3.8 flexible equipment: Equipment, structures, and components whose lowest resonant frequency is less than the cutoff frequency on the response spectrum,

3.9 floor acceleration: The acceleration of a particular building floor (or equipment mounting) resulting from the motion of a given earthquake. The maximum floor acceleration is the ZPA of the floor response spectrum.

3.10 Fourier spectrum: A complex valued function that provides amplitude and phase information as a function of frequency for a time domain waveform.

3.11 ground acceleration: The acceleration of the ground resulting from the motion of a given earthquake. The maximum ground acceleration is the ZPA of the ground response spectrum.

3.12 InclusIon rules: The rules that define the bounds of equipment included in a reference equipment class based on an acceptable range of equipment physical characteristics, dynamic characteristics, and functions for which seismic ruggedness has been demonstrated by experience data.

NOTE See 10.2.3.1 and 10.3.3.1.6

3.13 Independent Items: Components and eqLliprnent that (a) have dit1rent physical characteristics or (b) experienced different seismic motion characteristics. e.g.. different earthquakes. different sites, different buildings, or different orientationsJlocations in the same building.

3.14 median-centered in-structure response spectrum: In-structure response spectrum developed using realistic damping and best estimate modeling parameters to obtain the most probable structural amplification that could realistically occur for the level of the specified earthquake ground motion.

3.15 narrowband response spectrum: A response spectrum that describes the motion in which amplified response occurs over a limited (narrow) range of frequencies.IEEE 344 pdf download.