Development of grid-like structure hybridised advanced sheet moulding compound composite part with characterisation and prediction of the flexural stiffness

Abstract

To increase the mechanical properties of sheet moulding compound (SMC) and extend the application on structural components, cost-effective towpreg-based grid-like structures with varying spacing, layers and layout were constructed, numerically studied on the tray-based 3D part and finally defined, which were co-moulded with SMC in the one-shot compression process. The hybridisation effect on the global and local elastic flexural property was experimentally characterised for the 3D part and 2D plate. For the 2D plate, an adapted analytical model was proposed treating the hybrid SMC as a laminate of different plies. A parametric study evaluated the influence of manufacturing process variables on predictive accuracy. Plateau-shaped out-of-plane waviness in towpreg was identified as the critical variable, and one adapted exponential power distribution was tailored to capture the waviness and integrated into the analytical model. Furthermore, demand for thinner towpreg was identified.