Thermomechanical behaviour of short glass fibre reinforced polyamide

Short Glass Fibre Reinforced Polyamide 6.6 composites are increasingly used in structural automotive applications. The resulting fibre distribution within injection-moulded components has a major impact on their mechanical properties due to the complex flow path taking place while filling the mold. Even for simple structural geometries, resulting mechanical fields are heterogeneous. Moreover, the mechanical behavior of polyamide composites is sensitive to mechanical loads and especially to environmental conditions such as temperature and humidity. In this work, we propose to use Infrared Thermography to monitor heterogeneous energy dissipation during tensile tests for different PA66GF35 specimens with various short glass fibre distributions. In addition, the thermoelasto-viscoplastic constitutive model developed by A. Launay was used to simulate temperature evolution during the tests. It is shown that particular attention must be paid to improve fibre distribution considerations for a right prediction of thermoelastic couplings.