Activités de recherche :
de la fabrication de composites à renfort fibreux 3D par le procédé d’infusion
Doctorant: Chen LI1
Xiaojing GONG2, Arthur CANTAREL3
a promising method for composites manufacture with various advantages. It has
four main steps including preform set, resin infusion, curing and disclosing
process. Among all these processes, infusion is the most important step which
will determine the final quality of the part. Thus, numerical simulation of the
resin infusion is meaningful . The work performed and the results obtained
will be presented in the second part, which mainly focus on the permeability
estimation on random fiber models  and dual scales models and then the
future work is listed in the perspective.
2. Permeability estimation intra tow in the
For porous media, permeability tensor
is the most significant parameter to describe the property of the reinforcement
for infusion processing. As an intrinsic property of the porous material, K
can be calculated by Darcy's law based on the velocity field obtained by solving
Navier-Stokes equation and continuity equation together. Hence, the Stokes
equation can be used for free flow with the consideration of incompressible
fluid and the inertial term can be neglected in micro, meso and macro scales.
random position and size of the fiber producing codes are developed to set up
realistic geometrical models. Numerical simulation has been realized based on
we have studied the influences of several parameters on the flow of the resin
during infusion. It includes 3 micro-structural parameters: Î´min, L, Î”r and a
macro parameter: Îµ. Here Î´min is defined as
the minimum distance between two neighbor fibers among all the fibers; âˆ†r is the range of the fiber radius, L is the length of the square domain and
Îµ is the porosity. We have also used
Morris sensitivity method to analyze the influences of these parameters.
Porosity Îµ has the most obvious
influence on permeability while L has
a significant effect on average velocity compared with other parameters. These
influences observed in a Representative Elementary Volume (REV) can be
generated to whole structure.
3. Permeability estimation of dual scales in 3
In order to estimate the permeability in 3 directions
using dual scales: intra and inter tows, the model with random position codes
have been developed in this work. The idea of this model is to generate the
real position of the fibers, the determination of the permeability of 3
directions can be achieved by applying the calculation method mentioned above for
intra as well as inter tow. The results from this model seem very promising,
because the permeability obtained in the transverse section (Fig. 1) correlate
well with the results published in the reference . Moreover, the
permeability in the longitudinal direction obtained from
this model is much closed to that calculated by traditional method. Actually, to our knowledge no
any other works has been realized in the literature on the determination of 3D permeability at dual scales.
3D geometrical models of braided and woven fiber will be studied to set up for
(2) The two phases coupling free flow and porous flow will be studied to
detect the infusion character on both of 2D and 3D models. Parameters of
structure which may influence the infusion process will be defined. Their
interactive influences on the infusion will also be explored.
(3) A final method will be developed for flow front prediction at macro
scale with various local permeability on different position of the part(Fig. 2 for 3D simple part and Fig. 3 for 3D car bonnet).
Figure. 2. Macro porous flow at part level (3D simple part)
Figure. 3. Macro infusion process at part level (3D car bonnet)
Gantois, A. Cantarel, B. Cosson, G. Dusserre, J.-N. Félices, F. Schmidt, BEM-based
models to simulate the resin flow at macroscale and microscale in LCM
processes, Polymer Composites, 34 (8), 2013
Zhang, B. Cosson, S. Comas-Cardona, C. Binetruy, Efficient stochastic
simulation approach for RTM process with random fibrous permeability.
Composites Science and Technology,
W.R. Hwang, S.G. Advani. Numerical simulations of Stokes-Brinkman equations for permeability
prediction of dual scale fibrous porous media. Physics of Fluids, 22 (11), 2010