ISO 10846-1:2008 音響と振動 — 弾性要素の振動-音響伝達特性の実験室測定 — Part 1: 原理とガイドライン | ページ 6

3.1

vibration isolator

resilient element

isolator designed to attenuate the transmission of the vibration in a certain frequency range

Note 1 to entry: Adapted from ISO 2041:- ¹⁾ , definition 2.120.

3.2

resilient support

vibration isolator(s) suitable for supporting a machine, a building or another type of structure

3.3

test element

resilient element undergoing testing, including flanges and auxiliary fixtures, if any

3.4

blocking force

F _b

dynamic force on the output side of a vibration isolator which results in a zero displacement output

3.5

dynamic driving point stiffness

k_1,1

Note 1 to entry: The subscripts “1” denote that the force and displacement are measured on the input side.

Note 2 to entry: The value of k_1,1 can be dependent on the static preload, temperature, relative humidity and other conditions.

Note 3 to entry: At low frequencies, elastic and dissipative forces solely determine k_1,1. At higher frequencies, inertial forces play a role as well.

3.6

dynamic driving point stiffness of inverted vibration isolator

k _2,2

dynamic driving point stiffness, with the physical input and output sides of the vibration isolator interchanged

Note 1 to entry: At low frequencies, where elastic and dissipative forces solely determine the driving point stiffness, k_1,1 = k_2,2. At higher frequencies inertial forces play a role as well and k_1,1 and k_2,2 will be different in case of asymmetry.

3.7

dynamic transfer stiffness

k _2,1

Note 1 to entry: The subscripts “1”and “2” denote the input and output sides, respectively.

Note 2 to entry: The value of k_2,1 can be dependent on the static preload, temperature and other conditions.

Note 3 to entry: At low frequencies, k_2,1 is mainly determined by elastic and dissipative forces and k_1,1 ≈ k_2,1. At higher frequencies, inertial forces in the resilient element play a role as well and k_1,1 ≠ k_2,1.

3.8

loss factor of resilient element

η

ratio of the imaginary part of k_2,1 to the real part of k_2,1, i.e. tangent of the phase angle of k_2,1, in the low-frequency range where inertial forces in the element are negligible

3.9

point contact

contact area which vibrates as the surface of a rigid body

3.10

linearity

property of the dynamic behaviour of a resilient element, if it satisfies the principle of superposition

Note 1 to entry: The principle of superposition can be stated as follows: if an input x₁( t ) produces an output y₁( t ) and in a separate test an input x₂( t ) produces an output y₂( t ), superposition holds if the input a x₁( t ) + b x₂( t ) produces the output ay₁( t ) + b y₂( t ). This must hold for all values of a , b and x₁( t ), x₂( t ); a and b are arbitrary constants.

Note 2 to entry: In practice, the above test for linearity is impractical and a limited check of linearity is performed by measuring the dynamic transfer stiffness for a range of input levels. For a specific preload, if the dynamic transfer stiffness is nominally invariant, the system can be considered linear. In effect, this procedure checks for a proportional relationship between the response and the excitation.

3.11

direct method

method in which either the input displacement, velocity or acceleration and the blocking output force are measured

3.12

indirect method

method in which the vibration transmissibility (for displacement, velocity or acceleration) of a resilient element is mea­sured, with the output loaded by a compact body of known mass

Note 1 to entry: The term “indirect method” can be permitted to include loads of any known impedance other than a mass-like impedance. However, the ISO 10846 series does not cover such methods.

3.13

driving point method

method in which either the input displacement, velocity or acceleration and the input force are measured, with the output side of the resilient element blocked

3.14

flanking transmission

forces and accelerations at the output side caused by the vibration exciter on the input side but via transmission paths other than through the resilient element under test

3.15

upper limiting frequency

f _UL

frequency up to which results for k_1,2 are valid, according to the criteria given in various parts of ISO 10846