1 Scope
This part of GB/T 7962 specifies the test methods, test steps and data processing for the Young's modulus, shear modulus and Poisson's ratio of colourless optical glass.
This part is applicable to the test on the Young's modulus, shear modulus and Poisson's ratio of colourless optical glass.
2 Normative references
The following documents contain provisions which, through reference in this part of GB/T 7962, constitute provisions of this part. For dated references, subsequent amendments to (excluding correction to), or revisions of, any of these publications do not apply. However, parties to agreements based on this part are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. For undated references, the latest editions apply to this part.
GB/T 7962.20 Test methods of colourless optical glass - Part 20: Density
3 Terms and definitions
For the purposes of this part, the following terms and definitions apply.
3.1
Young's modulus
E
ratio of the applied tensile stress to the relative elongation of the object under the action of tensile stress
Note: the unit is Pascal (Pa).
3.2
shear modulus
G
ratio of shear stress to the relative transverse contraction of the object under the action of shear stress
Note: the unit is Pascal (Pa).
3.3
Poisson's ratio
μ
ratio of the relative elongation of object under force to the relative transverse contraction in the direction perpendicular to that of elongation
3.4
transverse wave
wave of which the propagation direction is perpendicular to the vibration direction of the particle in the medium, the propagation velocity is represented by the symbol VT; solid medium has a characteristic of not only bearing volume deformation but also bearing shear deformation, so transverse wave is generated where shear force alternately acts on solid medium; transverse wave can only propagate in solid medium
3.5
longitudinal wave
wave of which the propagation direction is consistent with the vibration direction of the particle in the medium, the propagation velocity is represented by the symbol VL; longitudinal wave is generated in any solid medium in case of alternative volume change
Foreword i
1 Scope
2 Normative references
3 Terms and definitions
4 Principle
5 Apparatus
6 Sample
7 Test steps
8 Result calculation
