ISO 4917-4:2024 地震に対する原子力発電所の設計 | ページ 6

3.1

behaviour coefficient

q

reduction coefficient applied to the force magnitude determined by linear analysis of earthquake events

Note 1 to entry: The coefficient, q, takes the dissipative effects into account that arise from the materials used, from the support structure and from the structural design.

3.2

centre of gravity

<dynamic> point of action of gravity, which can be considered as the point on the approximated single degree of freedom model of a structure, at which the acceleration is equal to the respective value of the response spectrum

3.3

damping

<modal> damping ratio of the respective eigenmode in mechanical systems

3.4

demand response spectrum

response spectrum that is specified for the design verification or qualification of structures, systems or components and that is usually obtained by multiplying the design response spectrum by safety factors and test-signal specific magnification factors

Note 1 to entry: Demand response spectra may also be created as an enveloping curve of the response spectra at the various places of installation.

3.5

design spectrum

enveloping, widened and smoothed single-degree-of-freedom response spectrum that is used as the basis for the seismic design

Note 1 to entry: In this context, it is differentiated between ground acceleration response spectrum (primary spectrum), building response spectrum (secondary spectrum) and component response spectrum (tertiary spectrum).

3.6

non-linearity

<geometric or physical> nonlinear relationship between the quantities of action and reaction resulting from the equilibrium and kinematic analyses of a system

Note 1 to entry: A physical nonlinearity is the nonlinear relationship between stresses and distortions resulting from a nonlinear material behaviour.

Note 2 to entry: A geometric nonlinearity is defined by a change of dynamic behaviour due to a change of shape, closing or opening of gaps, uplifting or sliding of a component.

3.7

primary system

heavy structure that supports one or more lighter-weight secondary systems (3.8)

3.8

secondary system

lighter-weight partial system that is supported by a heavy primary system (3.7)

3.9

single-frequency excitation

frequency, which has a time history in which at every point in time only a single excitation frequency (e.g. sine sweep, fixed frequency) occurs

3.10

test response spectrum

response spectrum determined based on the actual motion of the shaking table

3.11

upper limit frequency

frequency above which no significant seismic response in mechanical components would occur

Note 1 to entry: The upper limit frequency may be specified as the cut-off frequency of the excitation spectrum.