Quantitative Study of the Impact of Biaxial Test Protocols on the Derived Material Parameters for a PVC Coated Polyester Fabric

Fabrics have been used in tensile surface structures for over 50 years. Their unique properties, such as their high flexibility and low self-weight, make that these materials can be used in very efficient and architecturally unique constructions.However, due to these materials consisting of woven fibres and different interacting layers, deriving their mechanical properties unambiguously has proven difficult. Current biaxial testing methodologies differ between institutes and much discussion exists as to how the obtained test results should be interpreted or to which extend these variations have a possible impact on the design and analysis of tensile fabric structures.To quantify the impact of the used testing protocols on the obtained results as well as the method for deriving the elastic constants from said results, we tested fabrics using various test methodologies so that the direct impact on the test results could be quantified. Following these tests, material parameters were derived using various methods to show the impact of both the used test methodology as well as the method of deriving the material's constants. These results were than deployed in various computational models to quantify the actual structural impact of these variations.This paper describes the analysis conducted on biaxial test results from a PVC coated polyester fabric (Sioen T2107), quantifying differences in the deviated material parameters and the resulting predicted stress-strain behaviour. The results show that taking different data sets can lead to significant different results, which then lead to a difference in the strains and displacements derived from the computational simulations.