IEEE 344-2013 pdf download IEEE Standard for Seismic Qualification of Equipment for Nuclear Power Generating Stations
cutoff frequency: The frequency in the response spectrum where the zero period acceleration (ZPA)asymptote begins. This is the frequency beyond which the single-degree-of-freedom (SDOF) oscillatorsexhibit no amplification of motion and indicate the upper limit of the frequency content of the wavelormbeing analyzed.
damping: An energy dissipation mechanism that reduces the amplification and broadens the vibratoryresponse in the region of resonance. It is usually expressed as a percentage of critical damping. Criticadamping is defined as the least amount of viscous damping that causes a single-degree-of-freedom (SDOFsystemm to return to its original position without oscillation after initial disturbance.
earthquake experience spectrum (EES): The response spectrum that defines the seismic capacity of areference equipment class based on earthquake experience data.
flexible equipment: Equipment, structures, and components whose lowest resonant frequency is less thanthe cutoff frequency on the response spectrum.
floor acceleration: The acceleration of a particular building floor (or equipment mounting) resulting fromhe motion of a given earthquake, The maximum floor acceleration is the zero period acceleration (ZPA) ofhe floor response spectrum.
Fourier spectrum: A complex valued function that provides amplitude and phase information as afunction of frequency for a time domain waveform.
iragility response spectrum: A response spectrum that defines the ultimate seismic capability of theequipment under test based upon fragility data.
ground acceleration: The acceleration of the ground resulting from the motion of a given earthquake. Themaximum ground acceleration is the zero period acceleration (ZPA) of the ground response spectrum.
inclusion rules: The rules that define the bounds of equipment included in a reference equipment classbased on an acceptable range of equipment physical characteristics, dynamic characteristics, and functionsfor which seismic ruggedness has been demonstrated by experience data.NOTE-See 10.2.3.1 and 10.3.3.1.
independent items: Components and equipment that (a) have different physical characteristics or (b)experienced different seismic motion characteristics, e.g., different earthquakes, different sites, differentbuildings, or different orientations/locations in the same building.
median-centered in-structure response spectrum: In-structure response spectrum developed usingrealistic damping and best estimate modeling parameters to obtain the most probable structuraamplification that could realistically occur for the level of the specified earthquake ground motion.
narrowband response spectrum: A response spectrum that describes the motion in which amplifiedresponse occurs over a limited (narrow) range of frequencies.
natural frequency: The frequency(s) at which a body vibrates due to its own physical characteristics (massand stiffness) when the body is distorted in a specific direction and then released.
operating basis earthquake (OBE): An earthquake that could reasonably be expected to occur at the planisite during the operating life of the plant considering the regional and local geology and seismology andspecific characteristics of local subsurface material. It is that earthquake that produces the vibratory ground