Caracterisation combinee de la permeabilite et de la compaction des renforts fibreux dans les procedes de fabrication des composites par infusion

The manufacturing of composite parts by resin infusion consists of applying vacuum inside the cavity of a mold composed of a rigid plate sealed with a flexible membrane. A liquid polymer is infused by gravity through a fibrous reinforcement as a result of the applied vacuum. The use of this process has greatly increased since it enables the manufacturing of large parts at relatively low cost. The numerical simulation of the process reduces the conceptual time required to set-up the fabrication process. The physical parameters of the materials used in the simulation software must be evaluated experimentally. During an infusion, the flexibility of the membrane enables an expansion of the fibrous reinforcement, thus a gain in thickness. The permeability depends on the fiber volume fraction and is not a constant parameter in time for the infusion processes. The actual methodology for the characterisation of permeability and compaction of fibrous reinforcements in rigid molds requires many different experiments. Moreover, this methodology is not adapted to the true operating conditions of resin infusion. In this work, a new methodology is proposed in order to obtain during a single experiment the expansion and permeability of a fibrous reinforcement for different fiber volume fractions. A new experimental test bench has been developed that enables a combined characterisation of permeability and expansion of the fibrous reinforcement. These parameters are then used in the infusion module of PAM-RTM to validate resin infusion in a part of variable thickness. Finally, a study was conducted on the fairings of the solar car of Ecole Polytechnique de Montreal, in which it was shown that a numerical simulation can help to determine an effective infusion strategy. The numerical results of the infusion of this complex part are then studied and compared with a real infusion to complete the validation of the numerical software.