Boundary element approaches for filling simulations of anisotropic reinforced preforms used in the resin transfer molding process

The boundary element method (BEM) is implemented in the simulation of the filling of anisotropic fiber reinforced preforms used in the resin transfer molding process (RTM). They are analyzed both as a homogeneous and a non-homogeneous domain. In the former case, two injection regimes are considered: constant pressure and constant flow. The BEM results of flow front positions, pressure history and pressure profiles in the two main directions of permeability are compared to analytical and experimental results. In the second case of non-homogeneous domain, the domain integral appearing in the boundary integral formulation is treated by the dual reciprocity (DR) technique; the DR-BEM results of the curve pressure versus radial distance Pressure vs. Radial distance in the main directions of permeability are compared to numerical results obtained from the solution of the equation of pressure using MacLaurin series. In this case, the influence of the linear radial change of the fiber volume fraction on the flow front positions and on the curves of pressure versus radial distance is analyzed Pressure vs. Radial distance. For the homogeneous case, an acceptable coincidence between BEM and analytical results is appreciated as the circular inlet effect, which is considered in the BEM formulation and is not considered in the analytical method, lessens with the time. In non-homogeneous case, the coincidence among the DR-BEM and the numerical MacLaurin series results indicates that the DR-BEM is a promising technique to deal with the infiltration phenomenon of anisotropic reinforced preforms in non-homogeneous domains.