GB/T 33061.7-2023 Plastics—Determination of dynamic mechanical properties—Part 7:Non-resonance method under torsional vibration
GB/T 33061.7-2023 Plastics—Determination of dynamic mechanical properties—Part 7:Non-resonance method under torsional vibration
Basic Information
Scope
This document describes a torsional non-resonant method for measuring the shear complex modulus G* of rectangular or cylindrical solid plastics in the frequency range of 0.001 Hz to 100 Hz. Higher frequencies may lead to significant errors in the measured dynamic performance (see 10.1.1 and 9.5.1).
This document is suitable for measuring the dynamic storage modulus of plastics ranging from 10 MPa (hard rubber) to 10 GPa (fiber-reinforced plastics). It can also be used to study plastics with a modulus less than 10 MPa, but a simple shear (see GB/T 33061.6) or torsional deformation of a thin layer between parallel plates can provide a more accurate measurement of their dynamic mechanical properties.
This document is particularly suitable for measuring loss factors greater than 0.02, allowing the study of the dynamic performance of most glassy and rubbery relaxation regions as a function of temperature and frequency (see GB/T 33061.1).
Note: The torsion pendulum method (see ISO 6721-2) can be used for measuring loss factors less than 0.1, but the method described in this document covers a wider and continuous frequency range.