Infiltration of <i>Z</i>-direction Injection RTM Process Based on <i>Ex-situ</i> Toughening Technology

Abstract

Aimed at ex-situ toughening technology and Z-direction RTM process,Darcy's law was modified by introducing the saturation parameter. The partial differential equation describing the unsteady flow of the resin in the fiber preform was established. The effect of process parameters such as volume flow rate, resin viscosity and fiber preform's permeability during the constant flow process on the injection pressure was investigated. The resin flow between intra-tow and inter-tow of the preform with untoughened layers and toughened layers was simulated. The results show that the numerical simulation results are reliable. The inner pressure in the fiber performs increases with the increase of injection time. The injection pressure increases linearly with the increase of volume flow rate and resin viscosity, while decreases with the increase of fiber preform's permeability, which accords with Darcy's law. The infiltration visualization of resin flow through meso-scale and micro-scale fiber preform is realized, which provides an important supplement for prediction of the macro-flow in fiber preforms and provides guidance for actual process.

Keywords

• <i>ex-situ</i> toughening
• unsteady infiltration
• finite element simulation
• RTM process