Flow visualisation of a cavitating hydrofoil as part of a preliminary test validation study for a large numerical and physical research project.


Liquid Composites Molding and Curing Simulation

PAM-RTM, a resin injection software module within PAM-COMPOSITES, is used to simulate the injection or the infusion of a resin in a preform. It can also be used to analyze the curing of thermoset components, in the autoclave or out of the autoclave (OOA).

PAM-RTM can model a wide range of processes including:

  • Resin Transfer Molding (RTM)
  • Vacuum Assisted Resin Infusion (VARI)
  • Compression RTM (C-RTM)
  • High Pressure RTM (HP-RTM)

This module predicts how the resin flows in a preform that might include inserts (metals, wood, foam).

Typically, simulation results reveal:

  • filling time
  • risk of dry spots appearance or fiber washing
  • flow front velocity
  • pressure applied to the mold
  • porosity level
  • curing time
  • temperature and degree of cure evolution

With PAM-RTM, RTM manufacturing defects are eliminated and product quality is improved upfront in the product development process, before any tools are cut, thanks to optimization of the following parameters:

  • injection/infusion strategy (choice of LCM process)
  • injection pressure or flow rate
  • temperature cycle (tool and resin)
  • location of injection gates, vents and vacuum ports
  • type and positioning of the flow media
  • curing cycle

Simulation can also be used later in the process to correct manufacturing issues after they are identified.

RTM simulation of an automotive B-Pillar with PAM-RTM

A key parameter of Liquid Composites Molding (LCM) simulation is the permeability of the reinforcements of the preform. Permeability depends highly on fiber orientations, therefore, it is important to account for these fiber orientations in injection/infusion process simulation. Geometrical approaches can be used to approximate the orientations of the fibers in the preform. However, it can also use accurate fiber orientations computed in a PAM-FORM preforming simulation.

Thanks to its unique, high performance DMP solver, PAM-RTM can handle large numerical models using shell or solid elements. These large numerical models are frequent in the wind industry because of the large size of the components and in the automotive industry because of the detailed geometry requiring small element size.

The capacity to treat very large to very small models made of solid elements is unique to PAM-RTM. This solid modeling capability is required to capture how the resin flows through the thickness and to identify risks for internal dry zones.

Infusion simulation of the root of a wind blade using solid modeling to account for the flow media influence on the resin flow with PAM-RTM

PAM-RTM's leading capabilities include:

  • conditional opening and closing of the injection gates and vents
  • automatic flow rate control to minimize porosities
  • gravity effect
  • sequential draping module for an estimate of the fiber angle in the preform
  • chaining of filling and curing simulation with the possibility to include “overfilling”
  • coupling with PAM-FORM and PAM-DISTORTION
  • Design of Experiments (DoE) for variability analysis