Prepared by Dae Jung Kim, Supervised by Dr. Alfred Loos and Goker Tuncol
1. What is RTM?
4. Motive
7. Results and Conclusion
RTM is a technique for manufacturing high quality
In this study, the two process parameters of a
The results are compared with a simulation program
composite parts. In this process:
constant flow case, namely the filling time and the
using Finite Element (FE) solution. Results agree well.
1. Fabric preform is placed inside mold cavity.
pressure build-up at the inlet are estimated using a
Calculated process parameters:
2. Mold is sealed and closed.
simplified analytical solution based on Darcy’s Law.
The filling time: 340 seconds
3. Resin is injected into mold cavity to saturate preform.
The flow is assumed to be one dimensional.
The pressure build-up at inlet: 1.72*107 Pa
4. Resin cures, the mold is opened and the composite
part is formed.
1D Darcy’s Law:
u = flow front velocity (m/s)
K dP
u
m dx
Piston
Rigid Lid
Air Port
Fiber Preform
Resin
COMPARISON BETWEEN TWO METHODS:
K = fabric permeability (m2)
m = resin viscosity (Pa.s)
P = resin pressure (Pa)
5. Programming (using MATLAB)
Rigid Base
Resin Injection Pot
Rigid Metal Mold
2. Advantages of RTM
With RTM, parts with the following features can be produced:
 Lightweight with high fiber volume fraction and strength.
 Cost effective.
 Large in size and complex in shape.
 Good surface quality.
6. Simplified Mold Filling Simulation
 Dimensional accuracy (low tolerances).
 Easy to add inserts and special reinforcements.
3. Examples
Chair
Tennis
Racket
Aircraft
Components
Section
xo(cm)
xf (cm)
ho (cm)
hf (cm)
Shape
1
0.0
5.3
6.4
10.2
Tapered
2
5.3
7.9
10.2
10.2
Straight
3
7.9
12.4
10.2
7.6
Tapered
4
12.4
17.0
7.6
10.2
Tapered
5
17.0
24.9
10.2
6.4
Tapered