On Viscoplasticity Characterization of Natural Fibres with High Variability

Abstract

Zapas model has shown good results in characterizing viscoplasticity in polymers and composites. Typically all viscoplastic parameters for this model are obtained in creep and strain recovery tests at different stress levels and at different test length. Obtaining parameters for highly variable bio-based materials is more challenging: trends are hidden in the scatter and data fitting is complicated. This paper suggests “single specimen methodology” for complete viscoplastic characterization and identification.