Un modele biphasique pour simuler la mise en forme par compression des composites a fibres courtes

摘要

A two-phase approach is proposed to model the rheology of polymer glass-fiber compounds such as SMC or GMT during processing. Hence, we consider the compounds as formed by two disti8nct media: the fiber net and the polymer. The anisotropic behaviour, which is induced by the microstructure of the fiber net, is reduced to the simple case of transverse isotropy. The rheology of the two media as well as their interaction follows non-linear (in power law) viscous behaviours. The equations of this model are simplified to the case of the compression of SMC. This gives the formulation of a shell model whose equations are written into a finite element code. Simple examples of isothermal simulations thus show the strong influence of material and process parameters on the phenomenon of phase separation.