Inverse characterization of vegetable fibre-reinforced composites exposed to environmental degradation

The characterization of composite materials, particularly those reinforced with vegetable fibres, presents additional challenges, like the influence of the manufacturing process, fibre-matrix adhesion problems, progressive stiffness reduction or material degradation due to environmental elements (moisture, heat and UV) exposure. The present work studies the suitability of inverse characterization, based on modal properties, to determine the mechanical properties of jute fibre-reinforced composite plates, subjected to environmental exposure to simulate outdoors application conditions. With this method both the elastic and the damping properties of composite specimens are found, which highlights its great usefulness in the prediction of mechanical properties. It was found that this non-destructive method can better estimate material properties than the rule of mixtures, reflecting manufacturing, processing conditions and also the influence of moisture absorption and UV degradation on the mechanical properties of these natural fibre composites. This method is an important tool since it can be performed in the final parts where the results account for all external influences.