BS ISO 6721-6:2019 pdf free.Plastics一Determination of dynamic mechanical properties Part 6: Shear vibration一Non-resonance method. Various shear test specimen assemblies can be used. A suitable design is shown in Figure 2. Here the metal end-pieces P are cylindrical, but any cross-sectional shape is suitable as long as the end-pieces can be clamped rigidly in the shear load stage. The dimensions of the end-pieces and the polymer specimens S shall be chosen such that the deformation of the end-pieces under an applied load is negligible in comparison with that of the specimens. For a polymer whose shear modulus is less than 100 MPa, this will mean that the thickness of the end-pieces may be comparable with the thickness L 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 Formula (1). 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 %…