Viscolastic behaviour of short-fibre reinforced polyamide with damage

This article concerns the characterization of the viscoelastic behaviour of short-fibre reinforced polyamide taking into account microstructural damage. The purpose of the work is to identify the characteristic material damage function and the damage evolution during constant strain-rate tensile loading. Samples with different fibre orientations are tested in order to analyse the effect of the fibre alignment. This article focuses on the comparison of the analysis at two temperatures: 23 °C and 80 °C. A continuum damage model based on a work done by Schapery is applied. The results show that the damage is nearly zero under a certain stress and strain respectively and it intensively grows beyond this threshold. Further damage depends on both strain-rate and loading duration. The strain-rate dependency at 80 °C is similar to the one at 23 °C and lower strain-rates. The measured stress can be accurately predicted by the model.