ISO 18437-5:2011 機械的振動と衝撃—粘弾性材料の動的機械的特性の特性評価—パート5：測定値と有限要素解析の比較に基づくポアソン比 | ページ 6

3.1

dynamic mechanical properties

fundamental elastic properties of a visco-elastic material, i.e. elastic modulus, shear modulus, bulk modulus and loss factor

3.2

resilient material

visco-elastic material intended to reduce the transmission of vibration, shock or noise

3.3

Young modulus

quotient of normal stress (tensile or compressive) to resulting normal strain or fractional change in length for a long specimen of resilient material

Note 1 to entry: The Young modulus is expressed in pascals.

Note 2 to entry: The Young modulus for visco-elastic materials which are isotropic is a complex quantity with symbol E *, having a real part E′ and an imaginary part E″.

Note 3 to entry: Physically, the real component of the Young modulus is related to the stored mechanical energy. The imaginary component is a measure of mechanical energy loss.

3.4

loss factor

ratio of the imaginary part of the Young modulus of a material to the real part of the Young modulus (the tangent of the argument of the complex Young modulus)

Note 1 to entry: When there is energy loss in a material, the strain lags the stress by a phase angle, δ. The loss factor is equal to tan δ.

[SOURCE:ISO 18437-2, 3.2]

3.5

linearity

property of the dynamic behaviour of a resilient material 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 αx₁( t ) + β??? x₂( t ) produces the output αy₁( t ) + β??? y₂( t ). This holds for all values of α, β??? and x₁( t ), x₂( t ); α and β??? are arbitrary constants.

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

[SOURCE:ISO 18437-2, 3.7]

3.6

Poisson ratio

ratio of transverse strain to the corresponding axial strain resulting from uniformly distributed axial stress below the proportional limit of the material

[SOURCE:ISO 17561:2002 ^[11] , 3.1.1]

3.7

shape factor

ratio of the area of one loaded surface to the total force-free area in a sample for compression or tension test with bonded ends