Mold filling simulation of Natural Fiber Reinforced Composites processing by Resin Transfer Moulding (RTM)

MORÁN JUAN IGNACIO; FRANCUCCI GASTON MARTIN; RODRIGUEZ EXEQUIEL SANTOS

Lucerna

Conferencia; SAMPE-SETEC 12, 07th International Technical Conference and Forum; 2012

Seico

The numerical modeling of the infiltration of reinforcements during the processing of composite materials by Liquid Composite Molding (LCM) techniques is an important tool that allows predicting the flow front patterns, filling times and resin pressure developed during mold filling. Therefore, molds can be designed in the computer through numerical simulations using different injection strategies, until the obtained results are acceptable. This is very important to optimize the process and reduce the production costs. Darcy’s Law is widely used to model most of these processes. According to this law, the fabric property that affects the fluid flow is its permeability. Usually, this property is considered constant and depends on the fabric architecture, porosity and fiber type. However, the modeling of the LCM processing of natural fiber reinforced composites is more complex than synthetic fiber reinforced composites due to additional phenomena that take place simultaneously with the fluid flow, such as fluid absorption and fiber swelling. These phenomena modify the porosity and therefore the permeability of the fabrics as the infiltration process proceeds. In this work, some models that include the aforementioned phenomena are proposed for the simulation of the resin transfer molding (RTM) and/or vacuum assisted resin transfer molding (VARTM) processing of natural fiber based composites. These models take into account the variation in permeability of the fabrics as the fibers absorb fluid and swell, and predicted more accurately the flow front development through the reinforcement than the classic models that use a constant permeability value.