Characterisation and modelling of the temperature and rate dependent shear behaviour of a non-consolidated powder impregnated fabric

The shear behavior of a non-consolidated powder impregnated PA66/glass woven semipreg is investigated through bias extension tests at different temperatures and testing speeds in the thermoforming processing range, and compared to the behavior of the same material after a preconsolidation step. Results show in both cases an increase of the shear modulus with lower temperatures, as expected from the thermodependance of the matrix viscosity. In contrast with the preconsolidated samples, the semipreg does not present a dependence on shear rate, which is attributed to different friction configurations between the yarns. A model based on multiplicative decoupling allows for a good prediction of the shear behavior of the semipreg material.