Results & Conclusions

The main objective of the PLIT project was to provide a scientific approach to the physics of the LRI process, applied in aeronautics for the cost-efficient and clean manufacture of large high quality stiffened wing panel composite structures, by a “numerical process simulation model”, to study the resin flow during the impregnation, within the scope of the Green Regional Aircraft program of Clean Sky JTI.

A complete Test Bench was conceived and delivered to SICAMB during the project for the manufacturing of large stiffened wing panel GRA demonstrators by the LRI technology.

PANEL

Photo: Stiffened flat wing panel manufactured by LRI (courtesy of Alenia Aermacchi and SICAMB) 

The optimization of the LRI technology was done by a scientific approach to the physics of the LRI process, using numerical simulation for mastering the resin flow during the impregnation stage avoiding filling defects and improving the robustness of the process.

Two major points were addressed during the project: the development of an optimized simulation methodology for the LRI process, specially suited for the analysis of large parts and stiffened wing skin panels, and the generation of an in-depth understanding of the flow phenomena with more experimental data and experience.

For the validation of the LRI numerical model, experimental tests were carried out during the project and experimental filling times were accurately measured at some defined locations within the panels for the correlation with the simulation results.

The optimized LRI simulation methodology computes for the through-the-thickness resin flow in LRI processes with the significant advantage of a minimized computing time, specially suited for the analysis of very large panels.

Experimental characterization of permeability and viscosity model parameters were key factors for achieving a good correlation between experimental and simulation filling times.

LRI