Simulation of the Post-Infusion Stage of Vacuum Infusion With Resin Injection Gates Locked

The article considers a type of vacuum infusion molding of a thin-walled composite part, characterized by blocking the injection gates for feeding liquid resin at the moment of filling a multilayer porous composite preform with resin, followed by applying external compression pressure to equalize the pore pressure and the fiber volume fraction. The consequence of the gates blockage is the disappearance of the pressure gradient entraining the resin, and a sharp increase in viscosity, which violates the correct description of the resin propagation by the Darcy equation. The article considers in detail the model description of the process, which allows for a rational choice of the moment of blocking the resin inlets and the law of changing the controlled pressures: external compression and vacuum, acting in the outlet vent. Using the example of a thin-walled composite preform polymerized by vacuum infusion on an open mold, it is shown that the modeling technology, which allows to estimate the start moment of resin gelation, allows for preparing the state of the model for the final stage - simulating the solidification of a thermosetting resin using fractional calculations.