BS ISO 6721-6-2019 pdf download.Plastics一Determination of dynamic mechanical properties Part 6: Shear vibration一Non-resonance method.
5.2 Llectronic dala-proceuhig equipment
Data-processing equipment shall be capable or recording the force and displacement cycle amplitudes to an accuracy ci t 1 %, the phase angle between the force and displacement cycles to an accuracy oft OY and the frequency to an accuracy oft 10%.
5.3 Temperature measurement and control
Acrording to b’ 6721-1.
5.4 Devices for measuring test specimen di,ncnsions
Accorng to ISO oZ2.1L
6 Test specimens
6.1 General
According to ISOZZI.zl.
6.2 Shape and dimensions
Various shear test specinwn assemblies can be used. A suitable design is shown in Flgure2.. here the metal end-pieces P are cylindrical. but any cross-sectional shape is suitable as long as the end-pieces (an be clamped rigidly in the shear load stage. The dimensions of the end•pbeces and the polymer specimens S shall be chosen such that the deformation of the end-pieces under an applied load is negligible in campariwn with that of the specImens. For a polymer whose shear modulus Ia less than 100 MPa. this will mean that the thickness of the end.pieces maybe comparable with the thickness I of the specimens,
The cross-sectional shape of the polymer specimens in the plane of their bonded faces is not critical. although a rectangular section is recommended in order to simplify the application of a term representing the contribution to the specimen deformation from bending. See FormulaW.
The specimens are typically cut From a sheet of the polymer and bonded to the end-pieces to construct the shear test-specimen assembly. The dimensions of each polymer specimen shall not vary by more than 3 % ci the mean value. This dimension shall be sufficiently large to allow adequate accuracy to he achieved in the determination of dynamic straiti and hence dynamic moduli (see FurmuLi LUJ. In addition, it is recommended that the dimension Ii of the polymer in the direction of the applied load should be greater than 4L in order to make the correction los- bending negligible.
NOTE A variation In dynamic properties can be obsrrved between specimens of diltereni thickness prepared Imy mniecuon mouldi.g owing to dihlerences which can be present in the structure oW the polymer in each speclnwn
6.3 Preparation of polymer specimens According to ISO 67211.BS ISO 6721-6 pdf dowload.