乐播传媒

A new test fixture for biaxial stretching of polymeric sheets 

 By Davide De Focatiis

Abstract:

There is always a need for reliable experimental data, whether to support the development of constitutive models, or to provide parameters, and in general standards provide a convenient methodology. There are, however, often circumstances that prevent the use of standard methods, for example a limited supply of material, limited funds to purchase the equipment required, or just an absence of applicable standards. This talk will focus on one example in which a new test fixture has been developed to address a specific research requirement: the need for accessible and low-cost biaxial testing for polymers and elastomers. A remarkably simple fixture was designed based on a single degree of freedom mechanism and a variable number of clamps arranged along a circumference, able to stretch polymers biaxially using the actuation provided by a standard uniaxial test machine. Validation was performed on several elastomers by comparison with a twin-axis biaxial machine, and different variants of the fixture have also been compared in terms of number of clamping points and of grip design.