Three-dimensional resin transfer molding: Isothermal process modeling and implicit tracking of moving fronts for thick, geometrically complex composites manufacturing applications - Part 2

In the manufacture of complex thick composite structures, isothermal proces s modeling simulation tools analyzing the three-dimensional flow of resin i mpregnating the thick fiber preform are instrumental in initial process opt imizations. Re present a new implicit formulation based on accurately fakin g into account the transient nature of the time-dependent conservation of r esin mass and employing the pure finite element method to implicitly solve for the pressure field and to hack the flow front progression of the resin inside the mold cavity. Our emphasis is on thick composites. Our previous e fforts involved two-dimensional thin sections [1] and the implicit type app roach. The present method is an extension of that effort to three-dimension al thick composites. The numerical developments involving the present impli cit methodology and hacking of the resin progression flow fronts provide an improved and physically accurate representation of the physical problem. T hey do not involve the time step restrictions based on the Courant conditio n as in the traditional explicit finite element-control volume (FE-CV) asso ciated formulation discussed in Part 1 in this issue. Instead, we treat the transient process as a series of quasi-steady-state processes. For illustr ative purposes, the present developments are first validated with simple ge ometries, then extended to practical applications for isothermal conditions , and finally, contrasted to part 1 in this issue of this study.