De. Kranbuehl et al., IN-SITU SENSOR MONITORING AND INTELLIGENT CONTROL OF THE RESIN TRANSFER MOLDING PROCESS, Polymer composites, 15(4), 1994, pp. 299-305
An intelligent closed-loop expert control system has been developed fo
r automated control of the resin transfer molding process of a graphit
e fiber preform using an epoxy resin, E905L. The sensor model system h
as been developed to make intelligent decisions based on the achieveme
nt of landmarks in the cure process, such as full preform impregnation
, the viscosity. and the degree of cure of the resin rather than time
or temperature. In-situ frequency dependent electromagnetic sensor (FD
EMS) and the Loos resin transfer model are used to monitor and control
the processing properties of the epoxy resin during RTM impregnation
and cure of an advanced fiber architecture stitched preform. Once corr
elated with viscosity (eta) and degree of cure (alpha), the FDEMS sens
or monitors and the RTM processing model predicts the reaction advance
ment of the resin, viscosity and the impregnation of the fabric. This
provides a direct means for monitoring. evaluating, and controlling in
telligently the progress of the RTM process in situ in the mold throug
hout the fabrication process and for verification of the quality of th
e composites.