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Verification of a three-dimensional resin transfer molding process simulation modelExperimental evidence was obtained to complete the verification of the parameters needed for input to a three-dimensional finite element model simulating the resin flow and cure through an orthotropic fabric preform. The material characterizations completed include resin kinetics and viscosity models, as well as preform permeability and compaction models. The steady-state and advancing front permeability measurement methods are compared. The results indicate that both methods yield similar permeabilities for a plain weave, bi-axial fiberglass fabric. Also, a method to determine principal directions and permeabilities is discussed and results are shown for a multi-axial warp knit preform. The flow of resin through a blade-stiffened preform was modeled and experiments were completed to verify the results. The predicted inlet pressure was approximately 65% of the measured value. A parametric study was performed to explain differences in measured and predicted flow front advancement and inlet pressures. Furthermore, PR-500 epoxy resin/IM7 8HS carbon fabric flat panels were fabricated by the Resin Transfer Molding process. Tests were completed utilizing both perimeter injection and center-port injection as resin inlet boundary conditions. The mold was instrumented with FDEMS sensors, pressure transducers, and thermocouples to monitor the process conditions. Results include a comparison of predicted and measured inlet pressures and flow front position. For the perimeter injection case, the measured inlet pressure and flow front results compared well to the predicted results. The results of the center-port injection case showed that the predicted inlet pressure was approximately 50% of the measured inlet pressure. Also, measured flow front position data did not agree well with the predicted results. Possible reasons for error include fiber deformation at the resin inlet and a lag in FDEMS sensor wet-out due to low mold pressures.
Document ID
19960009062
Acquisition Source
Legacy CDMS
Document Type
Contractor Report (CR)
Authors
Fingerson, John C.
(Virginia Polytechnic Inst. and State Univ. Blacksburg, VA, United States)
Loos, Alfred C.
(Virginia Polytechnic Inst. and State Univ. Blacksburg, VA, United States)
Dexter, H. Benson
(NASA Langley Research Center Hampton, VA., United States)
Date Acquired
September 6, 2013
Publication Date
September 1, 1995
Subject Category
Composite Materials
Report/Patent Number
VPI-E-95-04
NAS 1.26:199792
NASA-CR-199792
CCMS-95-10
NIPS-95-06462
Accession Number
96N16228
Funding Number(s)
CONTRACT_GRANT: NAG1-343
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
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