Fully Predictive Micro-mechanical Modelling for Shear Viscosities of Continuous Fiber Reinforced Polymer Composites

Optimisation design of composite structures requires an accurate predictive model for forming behaviour. The simulation process contains a number of model parameters which include transverse and longitudinal viscosities of continuous fibre reinforced viscous composites, fundamental to predicting the shear rheology. Micromechanical interaction between fibre and matrix offers fundamental understanding of deformation mechanisms at the micro-scale level, leading to development of the fully predictive composite viscosity models, so as to eliminate any time-consuming experimental characterisation. The composite viscosity models were developed based on rheological behaviour during movement of fibres, and validation was performed using experimental results collected from the literature, indicating reasonably good agreement with the lower bound of the test data. It is suggested that non-Newtonian effects (rate dependency), viscoelastic effects and fibre rearrangement during shearing should be considered in the models to resolve the underestimation problem.